# Oscillating I.C. Engine



## Brian Rupnow (May 18, 2015)

A few years ago, Philip Duclos designed a rather homely (or so I thought) little engine with an oscillating cylinder, not unlike one of Elmer Verburg's steam powered "wobblers". The REALLY BIG difference was that this engine was gasoline powered.----and---It was a hit and miss engine---and it was air cooled. It was a very clever design, and according to Philip Duclos, it ran well. I want to build something different enough to be interesting, and to add my own personal touches to "pretty it up" a bit. I give Philip full credit here for his original design, and hope that wherever he may be now, that he smiles a bit when he sees what I am doing to his "Whatzit" engine.----Brian


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## bmac2 (May 18, 2015)

Ok Brian youve got me. Im hooked. Just have to see what you come up with on this one. If you can pull it off Im not sure youll be able to put it on the shelf with the rest of your engines . . . . this one might have to be kept in a cage.


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## Brian Rupnow (May 18, 2015)

Bob--I did a web search for "oscillating internal combustion engines", and didn't find any. Then I searched specifically for "Whatzit engine" (that was the name of the one Philip Duclos designed and built) and couldn't find anything.  I think this will be a lot of fun. I seem to vaguely remember a write-up where somebody had built one but they couldn't keep the spark-plug wire from jumping off when the engine was running, so they installed a stationary "spark-post" very close to the moving sparkplug, and the spark jumped the gap to fire the plug in the oscillating engine.


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## Cogsy (May 18, 2015)

This I have to see. I've missed your builds Brian, and I just knew you'd be back with something really special - although I half imagined you'd already have it built. It'll be even better to watch the design and build develop.

I can already see that this might end up being my next Rupnow engine build.


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## nemoc (May 18, 2015)

Brian,  When I first saw the whatzit engine I knew I would build one some day, haven't got to it yet, but it's on the list.  I too thought it was an ugly duckling.  I really like where you are going with it.  Can't wait to see it come together.


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## RonGinger (May 19, 2015)

I saw an oscillating cylinder marine IC engine several years ago at the Mystic Seaport Marine engine event. It was a very interesting engine and I thought about trying to model it. I have only seen one, it is a rare form.

It will be fun to see how this one comes out.


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## ShopShoe (May 19, 2015)

I'm glad to see another Brian Rupnow project underway.

Sparks jumping a gap? Now that's interesting.

I can't wait for the chips to start flying.

--ShopShoe


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## tornitore45 (May 19, 2015)

Very interesting and unusual project.
I wander how the sealing against compression is achieved since in steamer is usually dependent on the spring but suppose IC has much higher pressure.


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## Brian Rupnow (May 19, 2015)

So now, after another four hours of modelling, it becomes clearer how this can be. The green support stanchions are fixed in position to a base. On the non carburetor side, there is a steel ball bearing setting in the recess at the end of the stub-shaft on the side of the cylinder. Then there is a 1/4" set screw resting against the outer side of the steel ball, locked in position with a 1/4" hex nut. On the carburetor side, there is a 1/16" cross section rubber o-ring (I will probably use Viton because of the heat.) setting between the end of the boss on the cylinder side stub-shaft which is hollow, and a flat bottomed counterbore in the green stanchion. This provides an air tight seal. The carburetor is bolted to the outside of the stanchion, and doesn't move. I will probably stick a paper gasket between the carburetor and the stanchion, but for now I haven't shown it. In one of the pictures, you can see the intake valve on the same end as the sparkplug--it is an atmospheric intake valve and requires no valve lifter. The exhaust valve is on the other side of the carburetor block, and will be operated by a lifter. There is a single hole in the side of the cylinder, and as in the Webster engine, it serves as both intake and exhaust port. You can see the (purple) head of the exhaust valve in the cross section.


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## Brian Rupnow (May 20, 2015)

Hang on boys, I'm modelling as fast as I can!!! Wife and I had to drive to Hamilton this morning to welcome my newest grandchild, Benjamin--8 pounds 7 ounces born at 6:30 this morning.--Mom and baby are doing well---Ben looks just like me--No hair and no teeth!!! This engine is a four cycle. The carburetor is attached solidly to the dark green cylinder support stanchion, which does not move. Strange as it may seem, the valves are both mounted in the same block that holds the carburetor, so the valves don't move either. There is a cam lobe on the far side of the red gear, setting in a cut out area in the pale green crankshaft support and the "pinkish/purplish" rectangular part with the round dark blue pin in it is the exhaust valve pushrod. That round dark blue pin is the "exhaust valve lockout latch" that the "hit and miss lever" catches on to send the engine into "miss" mode.---More to come!!!---Brian


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## vascon2196 (May 20, 2015)

I am really liking this!

Looking forward to seeing this through.


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## Swifty (May 21, 2015)

Brian Rupnow said:


> Hang on boys, I'm modelling as fast as I can!!! Wife and I had to drive to Hamilton this morning to welcome my newest grandchild, Benjamin--8 pounds 7 ounces born at 6:30 this morning.--Mom and baby are doing well---Ben looks just like me--No hair and no teeth!!!



Hopefully another engine maker. We currently have 1 three year old grandson, with another 2 grandchildren on the way, one in August and one in September.

Paul.


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## Brian Rupnow (May 21, 2015)

The modelling is completed for this engine, except for riser blocks under the baseplate so the flywheel doesn't hit the bench-top. NOW---This is the point at which I may do something really crazy!!! Remember how, in another thread I asked about an offset, gear driven flywheel. You will see that even if this flywheel did have "deflector blades" soldered into the lightening holes in the flywheel web, to create a fan effect, the air wouldn't blow on the cylinder where I want it to. Now--If I extended that crankshaft support block closest to the flywheel about 2 1/2" horizontally, moved the flywheel over the same amount and mounted it on a stub shaft attached to the crankshaft support block, and popped a couple of 2.5" o.d. spur gears in there, the flywheel would be right where I need it to be.  One gear mounted on the end of the crankshaft and one mounted on the flywheel--the fan effect from the flywheel would blow directly over the cylinder fins. If it didn't work, I can replace the extended crankshaft support with one similar to what is shown in the model, move the flywheel back, and remove the gears. All I would be "out of pocket" for would be a couple of purchased hardened gears. (I could even make the gears myself for that matter.)---Whatcha think???


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## Swifty (May 21, 2015)

Good idea Brian, just don't forget that with the gears, the flywheel and fan blades will be rotating in the opposite direction.

Paul.


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## Cogsy (May 21, 2015)

I think it'd be interesting. If it didn't work out it should be easily reversible as well.


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## vascon2196 (May 22, 2015)

How about a pair of miter gears allowing you to drive a fan back across the fins of the engine block? I don't know....I just like watching the design develop in CAD and all the possibilities. Do what you think is best Brian! It is looking good!


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## Brian Rupnow (May 22, 2015)

Something unusual here---In his book 'The Shop wisdom of Philip Duclos' where these plans originated, Philip specifies the use of "Hot rolled or cold rolled steel" for the cylinder. He specifies cast iron for the rings. Okay--I can see the need for the strength of steel as opposed to cast iron because of the two pivot bosses on the outer walls of the cylinder, but I have never seen steel specified for a cylinder before.  I don't think that it is a mistake. I'm just very curious as to whether steel will work satisfactorily for the application.--Any opinions??----Brian


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## Brian Rupnow (May 22, 2015)

I really wish I could make the cylinder from aluminum, it would be so much easier to machine.  Almost every plan I have ever seen calls for the cylinder to be cast iron, and any that have an aluminum cylinder always call for a cast iron liner. I know, my weedeater, chainsaw and lawn mower all have gas engines with aluminum cylinders, and they seem to get away with it just fine. The aluminum I use is just common bar stock purchased from my local metal supplier, and I have never asked what grade it is. Probably 6061, but I'm not sure.  I don't know if all the other hundred million small engines with aluminum cylinders are running some special aluminum material that I don't have access to. I hope I get some more insight into this before I actually begin the build process.---Brian


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## Cogsy (May 22, 2015)

At least in small scale I believe steel works quite well. Bob Shores Peewee V4 that I'm currently building specs 12L14 for the cylinders, aluminium piston and cast iron rings. I think Steve Huck's V8 also uses this combination and I know he has many running hours on his engines.

As far as the Ali, I think you'd get away with it, but the pivots would probably have to be made of a different material, especially the (I assume) hollow one that the port/s run through. Using an O-ring instead of cast iron rings should protect the bore but if it did wear quickly you could either bore it out and reduce the pressure on the O-ring or insert a cast iron sleeve.


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## nemoc (May 22, 2015)

In my copy of his book the cylinder spec. is CRS, HRS or cast iron.  It's not in the text,  it is on page 128 above photo 8.  As for your question, I think the only problem with an aluminum cylinder on this engine are the pivot points.  I don't think the aluminum would hold up.


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## RonGinger (May 23, 2015)

For the small size engines we are talking about here just about any metal ought to work. Nothing gets heavily loaded. We dont run them long enough to do any real wear. If you make an aluminum cylinder and pivot how many hours do you expect it to run? Ill be most models dont run more than a few dozen hours in their lifetime. Has anyone ever taken a model apart and noticed major wear?

I am sure neither Phil Duclos or Bob Shores ever did any calculation to determine the metal type- they just specified what they liked to work with.


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## Brian Rupnow (May 23, 2015)

If I make the cylinder from cast iron, it will be fairly easy stuff to work with. The only issue I see with cast iron is that the bosses on the sides will be fairly delicate---will need to use a very sharp tool when machining them or they will pop right off of the main cylinder block.--(Don't ask me how I know this!!) However, the bore and fins are pretty easy to machine in cast iron. If I make the cylinder from aluminum it will be super easy to machine, and will be very "flashy", but I don't think the pivot bosses would last very long, and I don't know how the bore would stand up to interaction with a sharp edged cast iron ring on the piston.--Would probably be okay with a Viton ring and a bit of oil mixed with the fuel for lubrication. --Could possibly press fit a thin bronze bushing over the cylinder bosses to take the "wear factor" from oscillating. Steel would definitely be the material of choice in regards to strength and wear factor of the pivot bosses, and it wouldn't be too bad to machine the bore and the outer shape and the bosses.--Could however, be a real "bear" to machine the fins into. I plan on using an HSS slitting saw to cut the fins.--Decisions, decisions--


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## Barnbikes (May 23, 2015)

Could you make an aluminum cylinder and press fit steel pins into it for pivot points?

How about making the head out of steel and .750 deeper and put the pivots on it?


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## Brian Rupnow (May 23, 2015)

Barnbikes said:


> Could you make an aluminum cylinder and press fit steel pins into it for pivot points?
> 
> How about making the head out of steel and .750 deeper and put the pivots on it?


Barnbikes--I thought about making the head from steel and doing as you suggest.. It poses a problem though, since the intake/exhaust hole goes thru the pivot on one side. If I did that, then I would have to seal between the head and the cylinder on the side as well as on the top.---Brian


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## Brian Rupnow (May 23, 2015)

The cylinder is pretty simple. The slots which create the fins are the scary part. I know my small mill does a great job cutting .094" wide x 3/8" deep in aluminum. Probably it wouldn't grunt at cast iron. Steel though---Ah, Jeez, I'm not sure about that.


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## Swifty (May 23, 2015)

How about making it out of aluminium and making the pivot bosses larger in diameter, and also shrink fitting a brass or bronze sleeve on each side. As drawn, the walls of the boss are only 1/16" thick, a bit thin for aluminium.

Another idea, make the main piece straight sided, machine a counterbore in where the pivots are, and loctite a bronze boss in place. The boss could have a large head on it that fits in the counterbore, allowing more area for loctite.

Paul.


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## Brian Rupnow (May 23, 2015)

Swifty said:


> Another idea, make the main piece straight sided, machine a counterbore in where the pivots are, and loctite a bronze boss in place. The boss could have a large head on it that fits in the counterbore, allowing more area for loctite.
> 
> Paul.



Paul--I like that idea. but--air cooled engine--gets hot--Loctite releases when hot.


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## Swifty (May 23, 2015)

I just checked the highest temp handling loctite, only 180 C, not a lot. Could you make the area around the pivots wider and use small fasteners to hold the pivots in.

Paul.


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## Brian Rupnow (May 23, 2015)

Paul--I really like the idea of aluminum. It has a far higher "bling" rating than either cast iron or steel, doesn't rust, and best of all is really easy to machine. I don't think my small mill would have enough power to cut the fin-grooves into steel. I could indeed make the area around the pivots wider, and use small fasteners. It would require blind tapped holes so as not to break through into the combustion chamber---or---move the fasteners so they are either above or below the cylinder bore.--I will think on this----I've still got a ton of bronze here.--Thinking--Thinking---


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## Jasonb (May 24, 2015)

CI will polish up to a high "bling" if you want it to.

Why not do a practice cut in a scrap of the same grade steel to see if your mill is upto it before you decide


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## Charles Lamont (May 24, 2015)

You could make steel pivots rather like two-bolt pipe flanges with fixings above and below the cylinder centre line to give more depth to the blind holes. A short shoulder on the back would locate in the cylinder, and if you wanted, the whole asssembly could be put between centres for a final light cut to ensure the bearing surfaces of the pins were absolutely in line.


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## Charles Lamont (May 24, 2015)

Oh, and another thing. All that air being pumped in and out of the bottom of the cylinder is a criminal waste. How about designing it to at least allow the option of fitting some valves at this end? You could have a very compact little compressor! The maximum output pressure the engine would comfortably drive against could be increased experimentally by increasing the diameter of the piston rod. Worth a bit of thinking time, surely?


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## Brian Rupnow (May 24, 2015)

Or---How about an alternate design--aluminum cylinder with radial grooves (easier to make on a lathe), thicker cylinder wall, and hard press fitted steel pivots?


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## nemoc (May 24, 2015)

I like it!  Looks great and solves all the problems.


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## vascon2196 (May 24, 2015)

Brian Rupnow said:


> Or---How about an alternate design--aluminum cylinder with radial grooves (easier to make on a lathe), thicker cylinder wall, and hard press fitted steel pivots?



Looks like that design will work out sweet.


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## Brian Rupnow (May 24, 2015)

Without getting too far into fixing up the other bits--it would look like this.--Kinda cool, I think!!


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## Brian Rupnow (May 24, 2015)

That cylinder reminds me of the bee-hive that used to be on the old Bee-Hive Cornsyrup cans. Of course, you have to be a long ways on the wrong side of 50 to remember them cans.


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## Barnbikes (May 24, 2015)

Looks great. Need to make a round connecting rod guide though.

I started building one of these last year but talked to a guy at a local show who could never make his run and stopped mine. He claimed the flywheel in the plans is way to small.

As far as the spark plug you might have to make a plug with the old style screw on cap and have a eyelet on your wire so it does not fall off.


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## canadianhorsepower (May 24, 2015)

Brian Rupnow said:


> Without getting too far into fixing up the other bits--it would look like this.--Kinda cool, I think!!



Hi Brian
nice project, but the rotating mass transfer is so big it will be worst then a 
grasshopper.:hDe: engine vibration goes 90 degree forward to the power stroke in your case all the power would hit the ground and jump all over the place. I told you the same thing about your own design:fan: but you told me no it would be fine..........when I started working on your design after my cancer fight you told me "it's jumping all over the place change the crank balance" this is the same case

cheers
Luc


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## Brian Rupnow (May 24, 2015)

Luc--You may well be right. Almost all of the i.c. engines I have built will "jump all over the place" if they are not bolted down to a table. I'm not too concerned if it tries to jump around, as long as it runs. Many single cylinder engines used on lawnmowers, weed-eaters, chainsaws, and cement mixers would "jump all over the place" if you set them on a tabletop with out bolting them down and tried to run them.


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## Brian Rupnow (May 25, 2015)

Okay---the jury has decided. It is going to be an aluminum cylinder with pressed in steel pivots. I have had to do a few strange and wonderful things to accomplish this.  The engine as originally designed had a 4.5:1 compression ratio, and a 1" bore. I determined that when the piston is at top dead center, it stops .050" before the side of the pivot hole in the side of the cylinder. So--I reduced the diameter of the bore to 7/8" from the outboard end of the cylinder to .025" past the hole for the pivot. That gives me an extra .062" of wall thickness to hold the pressed in pivot pins in place, and still leaves .025" clearance between the top of the point where the 1" diameter piston stops it's upward travel and the beginning of the reduced bore diameter. This of course increased the compresion ratio to a higher number. Fortunately, the original design had the inside of the cylinder head extending down into the cylinder itself by a considerable amount. I was able to shorten this intrusion into the cylinder by a sufficient amount to restore the compression ratio to what it should be.


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## Brian Rupnow (May 25, 2015)

Like this---


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## Brian Rupnow (May 25, 2015)

I just had an amazing idea. In the cross section of the cylinder, you can see the extra "breather holes" cut in the cylinder con-rod guide to prevent pulling a vacuum when the piston is on it's way up from dead center.-This means that every time the piston travels down, a puff of air comes out of those holes. if I went absolutely steam punk crazy, and made up a couple of 180 degree u-bends  in brass hollow tubing and fitted them into two of the top holes, they would blow a blast of air over the cooling fins with every revolution of the crankshaft, as the piston travelled down in the bore!!


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## Brian Rupnow (May 25, 2015)

Check this out!!!


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## Brian Rupnow (May 25, 2015)

That's it!! All of the modelling is finished. I know the design has evolved since I started, but that is the nature of design. Sometimes I have to design a thing and look at it for a while before I decide whether or not it is practical or pleasing to my eye.---or "do-able" on conventional machine shop tooling. I don't know when I will actually start building this engine, but it probably won't be too far off. I will build the cylinder first, because that will be the trickiest bit of machining.---And Oh yeah--The jury is still out on those inserts in the flywheel, but they would create air flow!!!---Brian


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## Brian Rupnow (May 25, 2015)

Gotta have a plan of attack---


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## Brian Rupnow (May 27, 2015)

That went amazingly well!! I have to stop now and do some real work, but you have to admit--that IS a graceful shape.


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## hussien95 (May 27, 2015)

it look very Impressive engine,excellent work.


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## Brian Rupnow (May 27, 2015)

Well, THAT was a very interesting hour!!! My goodness, I love that mounted digital caliper.-I have never cut such accurate, consistently spaced fin grooves before. Nothing jammed, nothing broke, and I cut them at 215 RPM which is faster than I have ever used before, using my HSS parting tool and lots of dripped on cutting oil.


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## vascon2196 (May 27, 2015)

Nice job Brian...if that is the toughest part the rest of the build should be a breeze!


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## bazmak (May 27, 2015)

Nice one Brian,will watch this thread with interest.If you would supply drawings
i would like to make this my first IC engine.Looks good and nice and compact
Keep posting. Regards barry


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## Brian Rupnow (May 27, 2015)

Baz--You are a very brave man!!! My suggestion for a first i.c. engine is the good old tried and true Webster. If however, you have a desire to live dangerously, at least wait until I finish mine to see if it will run or not!! I know of at least two that were built to the original design. One by Philip Duclos, the original designer, and one by a fellow in Florida. I have made a few changes to the original design, and I have never had it confirmed that the original engines ever ran---well or otherwise.---Brian


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## Brian Rupnow (May 28, 2015)

Cylinder has had one end cut off and is bored to 1" diameter. Actually, it has two sizes of bores, 1" where the piston travels, and 7/8" in the actual combustion chamber. The holes have been drilled and tapped in the visible end. I always have to be very careful on a part like this that I don't "paint myself into a corner" and find that there is nothing to hold onto to do farther stages of machining.--I can now make a 1" diameter arbor that has a flange in the middle for bolting to the end of the cylinder which is drilled and tapped. On one side of the flange, the arbor extends into the bore of the cylinder, right up to the step in the bore. On the other side of the flange, it sticks out a couple of inches so I can hold it in the chuck on my lathe to part of the other end and into the chuck on my  rotary table to machine the flats on each side and the through holes.


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## Brian Rupnow (May 28, 2015)

So far, we're right on track. I know this cylinder is making things picture heavy, but it is a multi-step operation, and the new-bees appreciate the step by step pictures.  The next thing will be a trip over to the mill to tap the bolts in the cap end, and then into the rotary table to mill the flats and the drill/ream the pivot holes. I have a bit of a sneaky feeling that this aluminum may be too soft to run without a liner, but Hey--Nothing ventured -Nothing gained!! I've checked it out already, and if it is too soft, I can but in a cast iron liner and run a 7/8" piston.


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## nemoc (May 28, 2015)

Hey Brian,  Looks great so far.  I have no doubt it will run.  I did see a running example at Cabin Fever 4 years ( I think ) ago.  I looked through my photos of that trip but couldn't any pics of it.


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## Brian Rupnow (May 30, 2015)

The cylinder is finished. all went very well, with no mishaps, until when I was taking it out of the mill I realized that the flats were cut 45 degrees out of phase.  I thought briefly of committing Hari-Kari, but then realized that this was a good thing. The pressed in steel pivot pins will now be directly under two of the head bolts, so I can extend the thread right into the steel pivots and that will act as some additional "security" to keep the pivot pins from trying to escape, and will give more thread for the two head bolts directly over the pivots. Setting on one side of the cylinder is a cut off section from the piece of aluminum I started with ---it will become the cylinder head. On the other side is a chunk of 660 bronze, which will be the con rod guide on the other end of the cylinder.


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## Brian Rupnow (May 30, 2015)

No matter how I rationalized it, it just wasn't going to look good. So--I put in a second set of tapped holes in each end, and offset the hole pattern 45 degrees from the flat areas. The set of holes I don't use will be covered up by the caps bolted to both ends of the cylinder. I have an "undersize" 3/8" reamer (0.3735")which I used to ream the cross hole of the cylinder. All of my cold rolled round stock is .001" undersize, so I turned the pivots from 01 drill rod    to an exact .375", coated them with "press fit" #648 Loctite and after putting a 7/8" diameter slug in the top of the cylinder to guard against flattening it, I pressed the pivots in with my 1 ton arbor press. They went in HARD!!! I now see that I have milled away more fins on the sides than I intended to, but I'm going to have to live with that. That is one of the dangers of designing your own stuff and having two or three "iterations" of the same part.--You lose track of what you are doing when you actually make the part. Overall, though, I' liking this!!


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## Barnbikes (May 30, 2015)

Have you thought of putting a shoulder on the valve side pivot shaft? That way you would not have metal to aluminum wear. 

Just a thought.


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## Brian Rupnow (May 30, 2015)

Barnbikes said:


> Have you thought of putting a shoulder on the valve side pivot shaft? That way you would not have metal to aluminum wear.
> 
> Just a thought.


I'll probably put in a .010" washer made from brass shim stock on each side.


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## Brian Rupnow (May 30, 2015)

And so, the end of a good day. Making parts, fixing mistakes, and taking time out in the middle of the day to put up a clothes line for my oldest son's mother in law. (And yes, there is a story to that, but I won't tell it here!!)  That's just a dummy con-rod sticking in the brass con rod guide. If a person had a yard of that 660 bronze, you could trade even for a small island in the Caribbean. If  I sleep tonight and goodwife doesn't have any plans for me tomorrow, I'd like to make the cylinder head.


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## Cogsy (May 30, 2015)

In my head I thought it was going to be a lot bigger than it is - or you've got yourself some comically oversize scissors and pencils... Looking great so far.


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## Mechanicboy (May 31, 2015)

canadianhorsepower said:


> Hi Brian
> nice project, but the rotating mass transfer is so big it will be worst then a
> grasshopper.
> 
> ...



Nice to leveling of asphalt.


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## Brian Rupnow (May 31, 2015)

And now you know how I spent my Sunday, or at least a good portion of it. Lets see--I started at 6:00 this morning and it's 2:00 PM now. That's 8 hours, but I took half an hour to eat and 21/2 hours to model a conveyor for a customer. so---That cylinder head is a five hour part. It isn't perfect, but it's good!!!


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## Barnbikes (May 31, 2015)

What size spark plug are you using?


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## Mechanicboy (May 31, 2015)

I can see the spark plug is a NKG 6-CM, right?


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## Brian Rupnow (May 31, 2015)

Right!! it has an M10 x 1 metric thread. I can buy them at the local auto parts store. To go any smaller than that, I have to order them from a model engine parts supplier and have them shipped to me.


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## Brian Rupnow (Jun 3, 2015)

This morning I built the two stands that the cylinder sets in to "oscillate". What you don't see in the pictures are the bronze bushings I pressed/loctited into the aluminum stands. On the thick stand, there is a steel ball that fits into a coned recess in the pivot shaft, and a threaded set-screw in the stand that puts some pre-load on the cylinder so it sets up tight against an o-ring seal which is buried inside the other pivot stand. In he other angular support stand you can see the two #4-40 threaded holes that the carburetor and valve body attaches to.


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## jimjam66 (Jun 3, 2015)

Great progress and a unique (to me, anyway) idea.  Would you see an application for this, Brian, or is it a 'lets see whats possible' thing?


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## Brian Rupnow (Jun 3, 2015)

JimJam--As I pointed out at the beginning of this thread, the original design for this engine came from Philip Duclos. I believe this falls into the category of "Novelty Engine".  I don't really see any practical application for an engine like this, other than for fun. It is the "uniqueness" that attracted me.----Brian


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## bmac2 (Jun 3, 2015)

Hi Brian
_This_ engine is very close to the _WHAT THE? _ category. Great work and thanks for posting.

David: Most of these model engines are just smile generators. For your first runner Id suggest a glass of wine and Ill bet it can go right up to snort and chuckle.Thm:


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## Brian Rupnow (Jun 3, 2015)

By the way---Did I ever mention how much I dislike machining steel?? I am badly spoiled by using mostly aluminum and brass for the things I build.  My relatively small mill likes it that way too. However---There are times when nothing will do but steel. Such is the case with the piece in the foreground of the picture. The 1/2" hole gets an oilite bushing to support the crankshaft, the 1/4" hole in the bottom of the counterbore gets a stationary camshaft, the counterbore is where the cam attached to the large timing gear lives, and the horizontal slot is where a bronze  pushrod goes. The pushrod is rectangular, and has a slot in two opposing sides which fits over the steel slot to guide and support it, and one end rests against the cam.  I didn't have any cold rolled steel to make this part, but I remembered seeing a rusty, crusty piece of 1" thick hot rolled in my "metal storage bin". I did a bit of searching and found it, and was able to carve this fairly reasonable piece out of it. I still have a lot of work to do to finish it, but it is an interesting part of the engine.


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## Swifty (Jun 4, 2015)

Coming along great Brian, but I'm with you when it comes to machining steel, had my fill of it during 35 years of toolmaking, aluminium is so much better to work with.

Paul.


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## barnesrickw (Jun 4, 2015)

Had a rough patch with steel just this week.  Aluminum is much more fun.


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## deverett (Jun 5, 2015)

...and much lighter!

Dave
The Emerald Isle


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## Brian Rupnow (Jun 5, 2015)

I've had so much unexpected "drop in" engineering design work, that I am considering buying a new milling machine. (To get rid of some of the money!!) My BusyBee Craftex CT129 is still going strong, but I would like something a bit bigger, stronger, newer. I don't want a knee mill, I am quite satisfied with the square column mill-drills that are available. Busy bee has a new 1 HP mill, with a larger x and y movement and an R8 spindle taper. It is 110 volt, which is a good thing because I don't have 220 volt available in my small machine shop. Of course, this means that along with the mill, I will have to buy a new boring head, because mine has an MT2 taper and it is not the removable shank type. The mill comes with a chuck, but I would have to buy a 1/2"-R8 collet and a 3/8" R8 collet to hold my milling cutters, and I think it's about time I had a new electric center finder.  The price for everything including the sales tax is just under $3000, and my wife says "Go ahead!" Damn, I love that woman!!! I just came home and measured the space available in my machine shop, and the new mill is so much bigger than what I have that either the bandsaw or the 1" belt sander or maybe both will have to move out to the main garage. My "machine shop" is a seven foot square annex of one corner of my design office that never got used---it had an enormous old drafting table in it that never got used, so when I began this machining hobby 5 years ago the drafting table went and a wall was built to separate the machining area from the office area. I may be about to outgrow things---


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## bazmak (Jun 6, 2015)

Congratulations on having a very understanding Wife Brian
I dont know how old you are but as you get older you realise you 
cant take it with.The old adage,i will save up for it goes out of the window
If you can afford it then buy it and enjoy it now Regards barry


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## Brian Rupnow (Jun 6, 2015)

Barry--I'll be 69 in July. I've been very fortunate to have fallen into a ton of work this spring, which generated the money to buy a new mill. I am scrambling like mad now, trying to figure out where to put a new mill if I buy one. My current mill is 29 1/2" from end to end of handles on the X axis. The mill I am considering buying is 45" end to end of the handles. I could move my bandsaw out into the main garage and that would free up sufficient room in the machine shop, but next winter when it's 20 below zero in my main garage I wouldn't like it so much.-----Brian


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## bazmak (Jun 7, 2015)

Keep the mill and lathe together.If the bandsaw gets less use for shorter periods move it.I have similar problems,you have to prioritise space to machine.My bandsaw,grinders and linisher are moved to out of the way spaces and brought out as i need them for short term use.I am 68 and bought the new mill and lathe,enjoy now while you can.I got the R8/ef32 collet set
for $100,made a chuck for the lathe now i can grip anything from 2 to 20mm
in both machines.If your getting a new mill then spend a bit more on extras
If your short we can have a whipround. Regards barry


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## RonGinger (Jun 7, 2015)

$3000 sounds high- have you looked at the Grizzly G0704? I bought one a year ago and really like it- it is R8 and has a table just about the same size as my Jet knee mill. Its only about $1200

I don't know about the import issues of getting a Grizzly into Canada, but I bet if you drove down to the store in PA and brought one home in your car it wold not be bad.  And a nice road trip as well.


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## Brian Rupnow (Jun 7, 2015)

I couldn't let the whole weekend get away without building at least one part for the engine. We now have an outboard crankshaft support complete with bronze bushing (and no, I didn't use Loctite on it.) I have had a crazy/busy weekend working for a customer, doing  8 hours work which I had estimated and quoted at 4 hours work--(Hate it when that happens), painting headboards for grandkids new beds, and cutting dangerous trees out of the fenceline between me and the neighbour. There are two holes yet to be tapped in that aluminum part I just made for ignition points, but I will wait till I have the ignition points in my hand to check the hole position first.


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## Brian Rupnow (Jun 10, 2015)

A crankshaft web in the process of being born. I have decided to make this a 3 piece crankshaft, pressed together. The web is 5/16 crs flatbar.  A couple of tricks are involved here. #1--when drilling/reaming the holes for the crankshaft and the rod journal, don't use the mill vice. Put a flat piece of sacrificial plate on top of the mill table and clamp the bar which will become the web to the flat plate. Vices (at least the vices I can afford) always tip the piece being milled a small bit when closed on the part, and if you drill/ream these holes while the piece is held in the vice, the rod journal will orbit as it rotates, and you definitely don't want that. I use an undersize reamer for the two critical holes, at 0.3735" diameter. I use drill rod for the crankshaft, because it comes in at .00025 to .0005" oversize A total of  .0002" interference seems about right for this size of stock when press fitted together. If, in my judgement the pieces don't press hard enough, I will cross drill and dowel with a .093" hardened pin.


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## Brian Rupnow (Jun 10, 2015)

Tonight I finished the crankshaft web. The holes are reamed with a 0.3735" reamer. The crankshaft itself is made from 01 drillrod, which is about .0005" oversize, or 0.3755" diameter. The part with blue dye on it is a full 0.3755" diameter, and it will be the "pressed" area. The short polished area at one end has been polished down to 0.3735" for a "lead" into the hole in the web. The long polished area has been taken down to 0.375" to fit through all the bores and bushings it has to go in. I used #220 grit emery cloth strips 1" wide to do the polishing with. When I press it into the web, it will stick out about 1/2" on the "off" side. I do this to ensure that it doesn't go in crooked, which can happen when you are pushing through a relatively thin web---5/16" in this case. I will trim that end off flush with the web after the pressing is done. All pressing will be done with both pieces at room temperature. My 1 ton arbor press is not powerful enough to do this pressing, and my mechanics bench vice won't open far enough to do the job. I will take it to the factory where I am currently doing a bit of design consulting and use their 12 ton press for this operation. When I press in the short piece of crankshaft that the con rod fits onto, I will use my bench vice.


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## Brian Rupnow (Jun 10, 2015)

And check out that crazy bronze exhaust valve push-rod!!


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## Cogsy (Jun 10, 2015)

Looking good Brian. I'm eager to see how your funky looking governor operates/adjusts. At the rate you work at it won't be long.


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## Brian Rupnow (Jun 11, 2015)

The Rupnow Retirement Fund took a big hit today!!! A brand new milling machine from BusyBee. This thing is a monster compared to my old Craftex CT129 that I bought 6 years ago. This one is 110 volt, with a 1 1/2 HP motor. The travel in X axis is 16" and in Y axis is something like 8 1/2". It has an R8 spindle taper. I decided to buy a base for this one instead of making my own from angle iron like I did with my first mill. This thing is majorly heavy compared to my old mill. I know because I just unloaded it out of my pickup by myself with my old faithful cherry-picker engine hoist. It seems to be quite unstable, with high center of gravity. I will arrange some temporary bracing from 2 x 4`s to keep it from accidentally tipping over until I get it to it`s final resting place and can tie the top of the stand into the studding in a wall.


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## Brian Rupnow (Jun 11, 2015)

I can see a problem already. My old mill moved .002" for every graduation on the X and Y dials, and the table moved exactly 0.100" for each full turn of the dial.---On the new mill, each graduation represents .0025", and one full turn of the dial makes the table travel 0.125". It's not a question of which one is right and which one is wrong---It's a matter of me unlearning almost 6 years of moving .002" per graduation.--Wonder what I will screw up first???


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## Charles Lamont (Jun 11, 2015)

You could make a dial with 75 divisions.


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## techonehundred (Jun 11, 2015)

Time to get a DRO and quit looking at the dials.:hDe:


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## bazmak (Jun 11, 2015)

I have the same problem Brian,but each grad. is almost exactly 1 thou,
when you get used to it you can work in both.The mill does look big,is it going in your garage or next to your lathe ?


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## Brian Rupnow (Jun 11, 2015)

Baz--My garage is not heated (much) in the winter. It is below the main bedrooms of the house, so it gets a bit of heat by convection, but not much---water in containers will freeze!!!. I'm thinking I will put the bandsaw in the garage and sell my old mill to make room for the new mill in my little machine shop. I can probably stand the cold for long enough to cut something out on the bandsaw, but I want the mill in where it is always warm.---Brian


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## Brian Rupnow (Jun 11, 2015)

I have an idea percolating--I can probably sell my old mill with all the tooling for enough money to buy a set of decent DRO's for my new mill.


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## Cogsy (Jun 11, 2015)

I had a similar problem when I changed lathes but it didn't take long to adjust. Really though, a DRO would be a nice addition. Congrats on the purchase.


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## jimjam66 (Jun 12, 2015)

That looks a beaut, Brian!  Old-timers disease being what it is, a DRO is probably the only way to avoid disaster caused by old habits dying hard.  Well, based on my experience anyway ...


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## RonGinger (Jun 12, 2015)

Are you sure about those dial measurements? It sounds like you have a metric lead screw, or a 16tpi. I would check that carefully.


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## Brian Rupnow (Jun 12, 2015)

Ron--I did check it carefully. It is stamped right on each dial .0025". I put a dial indicator on the table and checked travel against the dial indicator reading, and with one full turn of the handle the table advances exactly 0.125".


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## Brian Rupnow (Jun 12, 2015)

I just checked with Shooting Star Technology. Their DRO system is actually made in Canada, in British Columbia. For two scales to do the X and Y axis and all the attendant hardware and software, it comes to $812.00 which includes taxes and shipping. That's a pretty hard lump to swallow, but their system is highly recommended by others who have bought the system through Little machine Shop in USA. If I can sell my old mill, along with all the tooling for $1000 I will buy them.


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## canadianhorsepower (Jun 12, 2015)

Brian Rupnow said:


> I just checked with Shooting Star Technology. Their DRO system is actually made in Canada, in British Columbia. For two scales to do the X and Y axis and all the attendant hardware and software, it comes to $812.00 which includes taxes and shipping. That's a pretty hard lump to swallow, but their system is highly recommended by others who have bought the system through Little machine Shop in USA. If I can sell my old mill, along with all the tooling for $1000 I will buy them.



Brian 
getting a 2 axes for a mill????? you'll regret for the rest of
your life get a 3 axes


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## Brian Rupnow (Jun 12, 2015)

And behold!!! Tonight we have a finished crankshaft. We almost had a finished con rod, but I got fooled----badly. I hunted around in my "bits and pieces" drawer and found what appeared to be a nice piece of 3/8" brass or bronze. I did my laying out, milled the profile, drilled and reamed the hole for the crankpin, put in the counterbore that the end of the con rod fits into, and was very pleased with myself. It was only on the final cut to part it off from the parent stock that it split cleanly in two!! What the Heck!!! It was only on close examination that I discovered that at some time in the past I had epoxied two pieces of 3/16" brass or bronze together for some reason.---RATS!!! Tomorrow I will make the same piece over again from real 3/8" material.


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## Brian Rupnow (Jun 12, 2015)

Luc, you may well be right. I will check and see what a 3 axis set up will cost. I've spent my toolroom budget for this year, so I'm going to be limited to what $ I can get for my old mill and all the tooling that goes with it.


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## canadianhorsepower (Jun 12, 2015)

Brian Rupnow said:


> Luc, you may well be right. I will check and see what a 3 axis set up will cost. I've spent my toolroom budget for this year, so I'm going to be limited to what $ I can get for my old mill and all the tooling that goes with it.



I got my set up Diltron DRO from japan to US spec 3axes 500.00 taxe and shipping include I still have the name of the agent I deal with.
BTW you got a nice millThm:Thm:

cheers


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## RonGinger (Jun 12, 2015)

Brian, I think your mill has a built-in DRO on the Z axis. No need to buy a 3 axis DRO. I see little use for Z to be included in the XY DRO- none of the calculation functions use Z, only X and Y.

Your mill appears to be the same unit as my Grizzly G0704 mill, at least from the photo you included. I like mine a lot.


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## Swifty (Jun 13, 2015)

I checked out the mill on the Busy Bee site, I can see a digital readout for the speed, but that's all. I have a knee mill, but only have  X and Y readouts, and do not miss having them on the Z axis. I either work to the dial on the knee or use the stop on the quill to get accurate depths.

Paul.


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## Brian Rupnow (Jun 13, 2015)

Both my new mill and my old mill come with digital readouts on the z axis.


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## Brian Rupnow (Jun 13, 2015)

The big move is about to commence. the bandsaw moves out to the main garage. The old mill moves out to the main garage until I can sell it, and the new mill moves into my machine shop. I went up to BusyBee this morning and bought a machinery moving dolly, and I must say I am rather impressed.  I don't think I would recommend it for moving a Bridgeport around on, but for machinery in the "under 700 pound" category, I think it's just the "cats meow!!!" All the other men I know are old farts like me, and I have two big strong sons, but one lives in a far off city and the other one is sick.-----So---This move will be a "Brian by himself move" as is generally the case. i think this little "cart" is going to be a real asset.


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## Brian Rupnow (Jun 13, 2015)

And so, my lads, we have the "Naked Machine Shop". The machinery moving cart worked marvelously, as advertised. The bandsaw and old mill are both out in the main garage. No tipped machinery, no mashed fingers, not even a tense moment really. Just very, very slowly and carefully, like porcupines making love!! I even washed 5 or 6 years of accumulated crud off the wall behind the mill!! Tomorrow I will do a big clean-up on the old mill and get it ready to advertise for sale. I don't want to move the new mill into place until I get this DRO business resolved, because the mill sets up against a wall in it's final position and I think I may have to drill and tap something on the back side of the carriage to hold a scale.---Much easier to do before I move it from the garage, where it has access all around it.


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## Brian Rupnow (Jun 14, 2015)

Just a "heads up"--I have listed my old mill for sale here.---Brian
http://www.homemodelenginemachinist.com/showthread.php?t=24593


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## Brian Rupnow (Jun 14, 2015)

Well guys, that went quickly. Two hours ago I listed my old mill and tooling for sale , and a guy just paid cash for it and said, "Keep it here until I can arrange to pick it up!!" DRO here I come----Brian


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## Brian Rupnow (Jun 16, 2015)

I actually managed to have a free morning at home today, so I thought I had better do something to keep this engine thread alive. I won't have access to a mill until my DRO's arrive and are installed, so I decided I would make as many round parts as I could on the lathe. I have turned and bored the blanks which will become my timing gears, plus enough extra gears to help out some poor fellow in USA who got my Rupnow Engine-2 three quarters built and then found out you can not purchase these particular gears---you have to make them!!! I also made the cam shaft, the bushing which presses into the cam gear, the ignition cam and the governor spool.


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## Brian Rupnow (Jun 17, 2015)

I am now a card carrying member of the infamous "Hole in the Wall Gang"!!! The new mill was about 4" thicker through than the old CT129 mill, and I couldn't afford the amount it would have protruded into my work space between the lathe and the mill. I will gain my 4" back by cutting a hole as shown The hole doesn't protrude into the adjoining room (which is just storage space anyways.) I gained back my 4" of space because the drywall was 1/2" thick and the "2 x 4" is actually 3 1/2" thick. I didn't cut through the bottom "footer" of the wall, because I didn't want to mess with the structural integrity of the wall itself. I will build a 1 1/2" thick  x 3" wide rectangular steel tubing spacer to go under the front and two sides of the mill stand, and the back side of the stand will rest on top of that "footer".  I still have to frame in the top and one side of the opening with 2 x 4's, and do a bit of trimming and plastering. I will have that finished by the time my DRO kit gets here.


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## bazmak (Jun 17, 2015)

Like the idea Brian.I am an expert on using every additional inch of available space.I have built lots of bookshelves by removing the front panel of plasterboard and setting the shelves into the wall.The shelves are sized to suit
paperbacks and only project 50mm

   Can you remove another section between vertical studs and make some useful storage shelving ? Regards barry


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## Swifty (Jun 17, 2015)

Barry, that could be a display shelf for your models 

Paul.


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## bazmak (Jun 17, 2015)

Like the idea,but her who must be obeyed would not


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## Brian Rupnow (Jun 18, 2015)

Nice work Baz. I am not a good 'finish' carpenter by any stretch of the imagination, but I'm great at framing and drywall work.--especially in the machine shop, where it doesn't have to meet too many critical eyes except my own.---Brian


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## Brian Rupnow (Jun 18, 2015)

For all you Canadians out there, who might consider buying this CX601 mill from BusyBee tools--A word of caution!! My old CT129 mill was set up so that each increment on the X and Y dials was .002" of table travel, and one full turn of a dial moved the table an exact 0.100". This made for a very easy mental calculation to determine how far you moved the table in either the X or Y axis. For some unknown reason, this new mill is .0025" movement for each graduation, and the table moves an exact 0.125" for one full turn. I checked this with a dial indicator, and it is correct.----This moves things into the realm of impossibility to do any kind of mental calculation of how many full turns and graduated marks you must turn the dials to move a given distance.----So---If you buy this mill, be prepared to use a calculator to figure out every move of the mill table, or shell out close to $1000 for a two axis DRO set-up. In my opinion, this is just about the stupidest thing I have ever seen. Caveat Emptor!!! (Buyer Beware.) If I had known about this before I bought the mill and got it home, I wouldn't have bought this particular mill.


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## RonGinger (Jun 18, 2015)

This is very strange. .150 advance  per turn is a 6.6666 thread per inch. I do not believe anyone made such a thread. But .15 inch is  3.81 mm and that is also a very strange pitch.

However 4mm is .157 inches, so if you are making a .007 error in your dial measurement then you have a 4 mm metric thread. 

You really need a good DRO to use this thing.


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## nemoc (Jun 19, 2015)

Hi Brian,  I have the same problem on my mini mill.  It's set at .0625 for 1 full turn,  But over time I have adapted.  With zero setting circles you can still do the math in your head, it just takes a little longer.  BTW you are making great progress on the engine.  Everything looks really good.


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## Brian Rupnow (Jun 19, 2015)

I'm really not looking for the sympathy vote here. After six years of milling only using the dials, I was beginning to wonder just how nice it would be to have a DRO set-up, but simply don't do enough "for pay" milling to justify the expense. Fortunately, I have had two steady months of engineering design work, which pays for the mill and accessories. I have sold the old mill and a bunch of other tools which I no longer use, and that has pretty well covered the cost of the DRO set I have on order. I do use my lathe and mill for quite a bit of prototype work for some of my customers, but it is all very "hush-hush" stuff. I think it is a good milling machine. It is very robustly built, and has a whopping great 8 1/2" travel in Y axis and 23 1/2" in the X axis travel. It's just that I really resent being forced into buying a DRO kit because of the way the dials are set up.---Brian


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## Brian Rupnow (Jun 19, 2015)

Things are going well with the milling machine installation. I have finished framing in the hole in the wall, and fabricated a welded sub base which is 1 1/2" thick, and exactly 3 1/2" shorter than the milling machine support cabinet base.  The cabinet/base will set on top of the base and on top of the bottom "2 x 4" at the bottom of the wall. (A 2 x 4 is actually 1 1/2" x 3 1/2").  the two "ears" sticking out from  near the front of the welded base will eventually be lag bolted into the concrete floor. The cabinet/base will set right up tight to the near side of the opening in the wall, and be lag screwed to the vertical 2 x 4 which forms one side of the opening. The opening in the wall is about 7" wider than the cabinet/base, so I may frame things in a bit more and screw the other side of the cabinet/base to the other side too---jury is still out on that.  The welded sub base will be bolted solidly to the cabinet/base before the mill and cabinet/base are moved into place. The 1 1/2" thick welded sub base is made from hollow rectangular tubing, so I will drill large clearance holes in the side closest to the floor and smaller holes through the top side for 5/16" bolts which will pass through drilled holes into the underside of the cabinet/base.


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## Brian Rupnow (Jun 19, 2015)

And that, my friends, is a beautiful thing!! Everything so far is going according to plan. I have to drill a few holes in the side of the cabinet to attach it to the stud beside it to give the stand some more stability. (These China stands are sufficient to hold up the mill, but they are pretty damned wobbly when you have a 500 pound mill setting on top of them)---to say nothing of top heavy. I don't want my epitaph to read "Here lies Brian, crushed to death by his own milling machine that toppled over on him!!" The only comment I have on this work so far, is that the steel in the base of those China stands is harder than the Devil's horn. It appears to be made from the same material as old bed rails that I have "re-claimed" for projects. I almost gave myself a hernia drilling eight 5/16" holes thru the base to attach my welded sub base. I have to disassemble everything and paint my welded sub-base with grey Tremclad (rust resistant) paint.


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## bazmak (Jun 19, 2015)

Good work Brian,i get a lot of pleasure from this sort of work,and as soon as your done you find further improvements.Those storage drawers to the right look as though they are just waiting to be recessed in the wall ? When your tight for space the things you do


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## Brian Rupnow (Jun 20, 2015)

No, the storage cabinets which were custom built to fit just under the table of my old mill are too high to fit under the table of my new mill. I have to cut one drawer off the height to keep them more or less in their old position. They will not be recessed into the wall.


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## Brian Rupnow (Jun 20, 2015)

My apologies to all who were following the build thread on this engine. I know it has segued into a topic about installing a new milling machine, but such is the nature of home shop machining. I promise--I will get back to the engine build as soon as I have the new mill all sorted out.---Brian


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## Cogsy (Jun 20, 2015)

Scared me for sec there Brian - first line of the post sounded like you were abandoning the build! Keep posting as you have been I say. Lots of interesting stuff to read and learn about and it's all part of the journey on this engine.


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## Swifty (Jun 20, 2015)

I'm still enjoying the information about installing your mill, once you get a readout fitted, you will be in another world.

Paul.


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## bazmak (Jun 21, 2015)

I concur,im waiting for more photos for the mill.Almost forgotten about the engine


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## Brian Rupnow (Jun 21, 2015)

So there we have it, girls and boys!! The "hole in the wall" has been transformed in to "The Mill Alcove!!". I had hoped to get a first coat of paint on it today, but have to wait overnight for the acrylic caulking compound to dry. The floor has been drilled and two concrete anchors installed and the side of the cabinet has been drilled so I can lag screw it to the near side stud.


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## Brian Rupnow (Jun 22, 2015)

The machine shop is as ready as it can get for the new mill-----but------I have decided to set the mill up in my main garage because--I need the mill to make the brackets to mount the DRO. I can not put the mill into the shop until the DRO's are mounted because of very little access to the back of the machine in it's final destination. To add to the confusion, the Tee slots are a different size than my old mill, so I have to make new keys for the bottom of two vices and my rotary table. I bolted a 2 x 4 to the underside of the cabinet/base in the area that would set on the bottom sill plate in my machine shop wall, and that let me install 4 concrete anchors to stabilize things. My DRO's were supposed to arrive today from UPS, but I just got notified they have been held up at Canadian Customs and won't be delivered until tomorrow. What a crock!!! That's another chunk of money added onto everything else. Maybe they are looking for opium in the DRO box!!!


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## Brian Rupnow (Jun 23, 2015)

My 2 axis DRO kit from Dropros arrived today. Everything seems to have survived the trip from California in good condition, and the items in the kit appear to be of very high quality. There is a good installation manual, users manual, and a CD which I haven't had a chance to look at yet. Everything was packed in one cardboard box with what seems to be about 20 cubic foot of Styrofoam popcorn. Right now, after having opened all of the packages to inspect for shipping damage, and a quick look thru the installation manual, it seems a bit overwhelming.---I am thinking "Rocket scientist required" but I'm sure that after I have a bit of time to familiarize myself it won't be quite so daunting. I've lost track of my total cost now, but it is getting close to $1000----I will know better after I have a chance to plow thru my Visa bill. ---Brian


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## bazmak (Jun 24, 2015)

You cant take it with you,you have worked hard for it,enjoy it


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## Brian Rupnow (Jun 24, 2015)

So, what do you do when you have a chip making, oil splattering milling machine in one bay of your garage, and a hot-rod with a white convertible top and tonneau cover in the other bay?---Answer---you improvise. I have a collection of various tarps that I have accumulated over the last 40 years, and an overhead beam in my garage.--I'm certain that I probably picked the nastiest, dirtiest tarp of all, but it will get the job done on a temporary basis. I need the milling machine to make the brackets to mount the DRO's in the coming week. As a point of interest, you can see the big power hacksaw that I built about 45 years ago in the foreground. I was building "wrought iron" railing and room dividers as a sideline back then. The saw will handle anything up to 5" diameter. I only use it occasionally now, and for cutting drill rod.


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## Brian Rupnow (Jun 25, 2015)

Morning is off to a bad start.---Went to machine a bracket and found that the  BusyBee 1/2" and 3/8" collets  with R8 taper do not fit into their mill which is designed for R8 tooling. Waiting for 8:00 to get to the bottom of this. The chuck and boring head fit fine, just not the collets. These collets do not have the internal seat for the shank of the endmill to set up against either, like my MT2 collets had. Perhaps I am missing something here, but right now I'm righteously ugly!!!


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## Brian Rupnow (Jun 25, 2015)

The plot thickens--I called BusyBee in Barrie, raised merry Hell, and told them I was coming over to return the collets and buy dedicated end mill holders. When I got there, everybody was standing around looking non-plussed, and told me that they have the identical machine to mine still on the show room floor, and that neither there collets NOR there end mill holders would fit in the spindle of their machine. I was then referred to corporate head office in Toronto, and told I should dismantle my new machine which has never been used yet, and back off the screw in the spindle housing. At that point I got quite vocal and began threatening law-suit. After getting no joy at all from Busy Bee, I decided that perhaps it would be wise to go to a REAL tooling shop and borrow a REAL cutting tool holder with an R8 shank.---I did---and it doesn't fit my mill either. I am now setting in my office, measuring the slots in the R8 shanks, and seeing that on the ones that do fit my mill, the slots are 0.200" wide and 0.100" deep. The ones that don't fit have a slot 0.150" wide and 0.060" deep. I am going to sort this out, but it's a pain in the a$$.


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## bazmak (Jun 25, 2015)

Considering the Chinese make good products most of the time.i am still amazed
that so much goes wrong.If you read my thread on the batteries for the edge finder you know what i mean.Keep us informed when/if you get to make chips


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## Brian Rupnow (Jun 25, 2015)

General consensus on the other machining forums is to remove the pin from the spindle. Apparently it does nothing but cause frustration and is bound to fail sooner or later even if it does fit properly. I sincerely hope that will solve the problem.---Brian


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## Swifty (Jun 25, 2015)

A couple of the older Bridgeports at work had worn pins, it made no difference as the collets still tightened up.

Paul.


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## tornitore45 (Jun 26, 2015)

> General consensus on the other machining forums is to remove the pin  from the spindle. Apparently it does nothing but cause frustration and  is bound to fail sooner or later even if it does fit properly. I  sincerely hope that will solve the problem.---Brian



Truly, that is the solution although it forces you to get intimate disassembling your new mill.

My mill worked for a couple of year before the pin got dislodged 1/2 way and gave problems.  The only function I can see is to prevent the collet to spin if it is loose, but we would never do that, right?


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## Charles Lamont (Jun 26, 2015)

Apparently the keyway in an R8 shank should be 5/32" wide and 3/32"
deep, -0, +0.010".


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## Brian Rupnow (Jun 26, 2015)

I have removed the pin. I have complained loud and long to all levels of management at BusyBee. They are all aware that there may be a problem with ALL of the CX601 mills across Canada. I get very upset when something like this happens, but I have to remember, BusyBee, with whatever problems they may have, have given me good service over the past six years. I get mad, as anybody would in a similar situation, but I don't want to cut off my nose to spite my face!!! With the pin removed, the mill will take all of my different equipment with R8 shanks. I have made my first cuts in cold rolled steel with the new mill. It is no longer virgin. These are new machine growing pains. They definitely do not make me happy, but they don't make me want to label the machine as junk either. My previous smaller mill was from BusyBee, and it served me faithfully for six years.


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## Brian Rupnow (Jun 26, 2015)

The mill is up and running. My God, what a powerful  monster it is compared to my old small mill. I was side milling and end milling in steel, taking cuts twice as deep as my old mill and it never even grunted. I'm getting off to a rocky start here, but I think it's going to be okay. Tomorrow I start doing some layout work for the DRO brackets. I will probably model the brackets in 3D cad and lay out the areas of the mill where the DRO's attach. There aren't that many brackets to be made, only 3 from what I can tell right now, and they are all associated with the Y axis scale and reader head. The X axis scale just attaches directly to the rear of the table. I have a lot of "other stuff" going on this coming week, but hope to make good headway with the scales.---Brian


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## Brian Rupnow (Jun 26, 2015)

Now that I have totally polluted this build thread with ramblings about my new mill, I'm rethinking things. The oscillating engine will get finished, but I am being asked on a number of forums to go into more detail about the mill and the installation of the DRO package, and I can see a lot more postings being required to address all the mill related questions. I am going to leave this thread now, and pick it up again once all my work on the mill and the installation of the DRO kit and relocated head lifting handle are completed. My new thread will be titled "CX601 Milling Machine".


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## Brian Rupnow (Jul 19, 2015)

Now, where the heck was I when the lights went out two months ago---I have a big tin can full of parts, and I'm certain that I would be much happier if they were all bolted to something to kind of make sense. I will now try and get some fun out of my new mill, and whittle out a baseplate.---Brian


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## bmac2 (Jul 19, 2015)

Holy cow. Brian Id almost forgotten about this build. In going to have to go back to the start and read it over.


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## Brian Rupnow (Jul 20, 2015)

Well, it doesn't look THAT much more impressive with all the pieces assembled on the baseplate.--In the background you can see the slice of 1" x 5 1/2" diameter bronze that is destined to become a flywheel. And yes, I do have the gearblanks turned to diameter to cut gears from. Also, in the background, you can see the 3/4" x 1 1/2" aluminum "riser bars" that will lift the baseplate up high enough that the flywheel doesn't touch the tabletop.


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## Brian Rupnow (Jul 21, 2015)

There--I think that is a definite improvement with the risers in place under the base!!---And yes, those are the points and condenser I will use on the engine, displayed along with their part numbers. I purchase them from PartSource, an automotive supply house here in Barrie. The parent company is BWD automotive in Long Island, New York.--They are originally intended for use on some Chrysler automobile.


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## bmac2 (Jul 22, 2015)

Hi Brian. This is one wild looking engine. I was wondering are you going to mount the condenser there or hide it under the base?


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## Brian Rupnow (Jul 22, 2015)

bmac2 said:


> Hi Brian. This is one wild looking engine. I was wondering are you going to mount the condenser there or hide it under the base?


Bmac--That is one of those "I'll figure it out when I get to it" things. The condenser is shown there for display purposes only.---Brian


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## Brian Rupnow (Jul 22, 2015)

I'm about to head off into gear cutting territory, but I have a question wiggling around in the back of my mind about the aluminum cylinder. I like it. It's beautiful----but I don't know if it will stand up to the combustion process or not. If not, I will put in a cast iron liner, to take the bore down from 1" to 7/8". My question is, can cast iron be turned to have a 1/16" wall, or is that too thin to machine comfortably? The liner would only be 2" long. I have turned a few cast iron cylinders, but have very little experience with liners.---Brian


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## Swifty (Jul 22, 2015)

If you use a good grade of cast iron, I cannot see any problem with the thin wall. In use it will be supported by the cylinder around it. You may find it better to finish the ID first, then mount it on a mandrel to finish the OD.

Paul.


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## Charles Lamont (Jul 23, 2015)

Not long ago I made the 3/4" bore liners for the Westbury Seagull with the prescribed 1/32" wall thickness. No problem.


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## Brian Rupnow (Jul 24, 2015)

It's been a very "Geared up" morning hear!! I cut the two gears I require for the oscillating engine, and the four gears required for the flathead engine I built. Some fellow out in central USA built the Rupnow side valve/flathead engine and then realized he had no way to make the gears for it. I still  have some parting off to do, and some clean up, but these are the first gears I have cut with my new mill.


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## crankshafter (Jul 24, 2015)

Brian.
I can imagig turning the handle/counting turns and indexholes
Nice work Brian.

CS.


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## Brian Rupnow (Jul 24, 2015)

Actually, the 30 tooth and 15 tooth gears are easy to make on my set-up. The 30 tooth requires 3 full turns (always end up back in the same hole on the divider plate) and the 15 tooth required 6 complete turns, again ending up back in the same hole in the divider plate each time.


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## Brian Rupnow (Jul 24, 2015)

I just cut my first cam using the "Chuck Fellows Method"---(Google chuck fellows cam cutting youtube) and I must say, it works a treat!!! Thank you Chuck!!!--and---Since I haven't had time to rig a permanent depth stop on this new mill, I thought you might like to see the "Hokiest Depth Stop Ever"---But it worked very well. By the way--there are two gears on that piece of steel. I just haven't parted them off yet.


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## Brian Rupnow (Jul 24, 2015)

We've got gears. Lots and lots of gears. In fact, we've got a whole freakin days worth of gears!!! I have 8 hours in these gears!! I know that the two on my oscillating engine mesh properly---I've tried them. I haven't made up a test jig to check the mesh on my other four gears that are going to a guy in USA. I will make a test jig to check them tomorrow. The 3 jaw chuck on my lathe is about .0015 out of true center. The 3 jaw chuck on my rotary table tends to have a wondering true center. I know there is some "forgiveness' built into the design of these small spur gears, but I never feel really good about them until I have drilled a piece of scrap and inserted 4 short pieces of shaft to mount the gears on and actually turn them to see what is going to happen. Sometimes they are perfect. Sometimes they need an application of 600 grit carborundum paste and  spun for 15 minutes with the electric drill to get rid of any bind caused by eccentricity in my set-ups.


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## Brian Rupnow (Jul 24, 2015)

This post has nothing to do with the current engine build.---However--It does show 4 gears I made today mounted on a test jig, to see if they mesh properly without any binding. This time I was lucky--Smooth as silk!!!


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## Brian Rupnow (Jul 25, 2015)

This morning I made up the big and for the con rod, and the con rod itself, though as yet I don't have a piston on the other end of the rod. I also took the time to read the manuals and figure out how to find the center of a hole using my new DRO system. I might finish a piston today, but then I might not---It"s getting awfully nice outside, and I was in the shop for 10 hours yesterday----


.


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## Brian Rupnow (Jul 25, 2015)

As with all newly assembled engines, this one was very stiff when all the bolts were tightened down. I have come to expect that, so part of this afternoon was spent trimming a bit here, stretching bolt holes a bit there, until finally it would turn over by hand. Of course a large part of the issue is that there is no convenient "handle" to turn the engine over with. I'm down to the point where most of the large pieces are finished, but I think I will make a start on the flywheel tomorrow, more to have something to actually grab onto to turn the engine with than anything. I have decided not to put the cooling vanes in the flywheel---at least for now---.


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## Brian Rupnow (Jul 26, 2015)

I just about got ahead of myself here.--I need a piston before I move on to the flywheel.---And man, what a big piston it is!!! I used bronze because it has good lubricity characteristics, and because that is what I had. I am not concerned about the mass, as it is a slow revving engine anyways.


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## Brian Rupnow (Jul 27, 2015)

Now THAT my lads, is a flywheel!!!


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## Gerhardvienna (Jul 27, 2015)

Brian Rupnow said:


> Now *THAT* my lads, *is a flywheel*!!!
> http://s307.photobucket.com/user/Br...24/FLYWHEEL FINISHED 001_zpsusv1ci9t.jpg.html
> http://s307.photobucket.com/user/Br...24/FLYWHEEL FINISHED 002_zpsicirbwi0.jpg.html


 
Agreed!!!
Best work from a master :bow::bow::bow:
Regards
Gerhard


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## Brian Rupnow (Jul 27, 2015)

Thanks Gerhard--I'm not sure I would class myself as a master, but I am certainly gaining a lot of experience. Things may slow down a little bit now---I've just been called back in for a few days at a local factory where I do design consulting on the projects they build. ----Brian


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## Gerhardvienna (Jul 29, 2015)

Brian Rupnow said:


> Thanks Gerhard--I'm not sure I would class myself as a master,....................
> ----Brian


 

I would! As so many others herein, you are!
Every look I take at the building reports here, I`m learning a lot. Thank you ALL.............
Regards
Gerhard


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## gbritnell (Jul 29, 2015)

Hi Brian,
On a side note, how are the new mill and digitals treating you?
gbritnell


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## Brian Rupnow (Jul 29, 2015)

George---I love them. I only wish now that I had bought 3 axis instead of two. There is a small puny digital readout that comes stock on the mill Z axis, but it is hard to see compared to the DRO readout.---Brian


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## Brian Rupnow (Jul 30, 2015)

A video for your entertainment.--No, the engine isn't running yet, but it is taking a major step forward.---Brian
[ame]https://www.youtube.com/watch?v=S8pbHkPGDRo&feature=youtu.be[/ame]


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## Brian Rupnow (Jul 31, 2015)

It looks like I'm down to carburetor time!!! This carb has only two largish pieces, and requires no throttle, so it shouldn't be as complex as many carb's I have built. The only thing I'm not really thrilled with is that both carburetors pieces are going to require 4 jaw work. I can do 4 jaw work, it just takes me an inordinately long time to get set up properly. However, it's not hard work---It's just picky work.


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## Brian Rupnow (Jul 31, 2015)

A minor change to that yellow valve body--(Which doesn't move with the rocking cylinder.) In the original version, the exhaust blew right out into the area where I intend to put a vertical cylindrical gas tank. Since the idea of hot exhaust blowing onto the side of a gas tank disturbs me a little, I have reconfigured the round boss to a new shape and put in an exhaust pipe which blows out at 90 degrees to the original exhaust path. Of course, this means that I have to plug the drilled exhaust port, but since i intend to silver solder the exhaust pipe in place, I can run a little more solder to hold the plug in place.---And as an added benefit, that also gives one less 4 jaw set-up than the original plan.


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## Brian Rupnow (Aug 2, 2015)

We have an exhaust valve body completed.--I'm very proud of this simple piece, because the main block had two 4-jaw set-ups required, and I manage to get both of them right. The exhaust pipe is soldered into place, as well as the cover for the cross drilled exhaust hole---(The cover kind of disappeared during the silver soldering process, but that's okay. It's not obvious on the finished piece). I have a bit of clean up and polishing yet to do on the part, but the exhaust valve body is essentially finished. Next up comes the intake valve body/carburetor, which bolts onto it.


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## Brian Rupnow (Aug 3, 2015)

Talk to me people--If you find this thread interesting at all, say Hi. I am coming into the final stages of this build, and although I post on three forums, it has mostly gone silent out there.I know folks are watching the thread, I see the post count going up each day.It's lonely out here!!!----Brian


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## james_III (Aug 3, 2015)

Hi, too puzzled to say anything that's make any real sense  Really like to see how this turns out.


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## Brian Rupnow (Aug 3, 2015)

Thank you for saying Hi James!! Leaping Lizards, Batman--Check out the intake valve/carburetor housing. That was my second part that needed to be done in the 4 jaw chuck. I may not like 4 jaw chuck work, but I certainly am improving at it. There are very few parts remaining to be made before I'm ready to run this baby!!!


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## Gerhardvienna (Aug 3, 2015)

Brian Rupnow said:


> .................................before I'm ready to run this baby!!!



We all are waiting for that, I`ve never seen an engine like this!
Regards
Gerhard


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## Brian Rupnow (Aug 3, 2015)

There must be something worse than having to make the same part twice, but right now I can't think of what it is!!! In the air-inlet of the carburetor you will now see a carburetor jet setting at 90 degrees to the air-flow, with a shiny #6-32 hex nut on one end and a smooth  0.175" diameter on the end facing away from the engine to hook my fuel line to. The needle valve, which isn't made yet, screws into the threaded end of the carburetor jet. Laying on the base of the machine, you can see the exact same part---WHAT???---Yes, the same part, except that the .040" hole drilled full length of it on the center, decided to take a turn for the worse and exit thru the side of the damned thing instead of out the other end. This happens to me sometimes. As I get more and more machining experience, it happens less often, but it still makes me say bad things and think evil thoughts when it does happen!!!


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## Swifty (Aug 3, 2015)

I'm still following along Brian, as I'm sure are a lot of others. It's a real bummer when you have to remake parts, usually happens to me when I rush things, the only consolation is that the second or third part takes less time as I've already had a trial run.

Paul.


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## Charles Lamont (Aug 3, 2015)

Brian Rupnow said:


> Yes, the same part, except that the .040" hole drilled full length of it on the center, decided to take a turn for the worse and exit thru the side of the damned thing instead of out the other end. This happens to me sometimes. As I get more and more machining experience, it happens less often, but it still makes me say bad things and think evil thoughts when it does happen!!!



I find it helps to take a 2lb lump hammer to the workshop door and throw it as far as possible down the garden.


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## Brian Rupnow (Aug 3, 2015)

I have reached that wonderful turnover point, where I have less pieces to make than are already made. I just printed off the last few drawings, and it looks like I'm down to two valves, two valve keepers, a needle valve, the hit and miss trip lever, and a gas tank. If I don't run into problems with leaky valves, I should have a runner before the end of August. Thank you to all who said Hi. It always happens at about this point in a build that has went on for a while--I start to wonder if anybody is following the build. I know people are looking because I can see the number of visits to the topic going up, but I guess my confidence needs a boost. It certainly makes me feel good when people take the time to stop by and say Hi.---Brian


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## Cogsy (Aug 3, 2015)

I know it's no consolation Brian, but I'm a world class expert on having to make the same part 2, 3 or even 4 times. Like Swifty, the more times I make a piece the faster I get at it. Worse for me though is making a part and having it be off quite a bit but still just usable, then trying to decide whether to be lazy and use it or try, try again.


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## vascon2196 (Aug 3, 2015)

Brian,

I've been following this every week since the start. I am looking forward to seeing it run...as of course you are.

Looks great.


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## gunna (Aug 4, 2015)

Cogsy said:


> Worse for me though is making a part and having it ........


....disappear into the mess under the lathe or where ever those little parts go when they escape.

Brian, have no fear, we may not be talking but by golly we are watching.
Ian.


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## jimjam66 (Aug 4, 2015)

Yup, still glued to the screen here ...


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## ShopShoe (Aug 4, 2015)

I'm watching Brian. I have to get my daily fix of Brian Rupnow posts. Thanks for posting "warts and all."  I think we all have to see "#$%&*" happens to the best of us sometimes to keep going.

--ShopShoe


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## Brian Rupnow (Aug 4, 2015)

Nothing really exciting or high-tech to post about tonight. Just a couple of valve spring keepers. The intake valve keeper is reamed to .125", the exhaust valve keeper is threaded #5-40 (And yes, that IS a hex machined onto the back side of it.). I picked up the springs at Brafasco while I was running all over town getting quotes for a customer, and managed to work 6 hours in my office on a design job.


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## Brian Rupnow (Aug 6, 2015)

I just had a very exhausting time this afternoon!! Okay, I know, horrible pun!! I turned the exhaust valve from cold rolled 1/2" diameter steel, and left it attached to the parent metal until I had a chance to lap it into the valve seat with #400 then #600 lapping paste. I know it is setting on a tub of 320 grit, but I didn't actually use any of that---it was just holding up the valve for a picture. After trying the "Blow your guts out thru the exhaust pipe test" to convince myself that the valve was really going to seal, I cut the valve away from the 1/2" cold rolled rod and installed it in the exhaust valve body, along with the spring, keeper plate, and lock nut. I left about .025" clearance between the locknut and the brass valve lifter, when the lifter is not "up" on the cam.


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## Brian Rupnow (Aug 6, 2015)

Dang!! I didn't notice how crooked that lock nut was setting until after I had posted the picture!! I took it off, turned it around, and put it back on. It's  setting straight now, but you're going to have to take my word for it.


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## oneKone (Aug 7, 2015)

Hahaha, coming along very nicely.


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## Brian Rupnow (Aug 7, 2015)

I found a precious hour this morning to whittle out an intake valve, lap it, and install it in the intake housing. I still have to make paper gaskets to go between the intake and exhaust housings and between the exhaust housing and the pillar it bolts against. I have never had much luck with the "gasket in a tube" stuff by Permatex nor anyone else.---Perhaps that is because I end up taking things apart and putting them back together again about 40 times before I'm actually finished!!!


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## Brian Rupnow (Aug 8, 2015)

And today we have the needle valve, complete with needle silver soldered to adjusting knob. It works.--I can blow a stream of air through the jet from the gas line end with my mouth firmly puckered around the fuel inlet.---As I close the needle valve with my fingers, it gets harder and harder to blow until finally it seals completely. Tomorrow it will be time to build gaskets.


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## tms6401 (Aug 8, 2015)

I'm still watching as well Brian. Unfortunately life get's in the way of even replying.

I am looking forward to it running.

Tom

PS ... How do you like the new mill?


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## Brian Rupnow (Aug 8, 2015)

Wife is having a nap---I kept working!!! Gaskets are made and installed. Valve timing is set. When spun by hand, I am getting a bounce back on compression stroke. Not a lot of bounce back, but it's there. Holy Cow---All that's between me and a running engine is the starter ring which bolts to the flywheel to let me engage my variable speed drill as a starter!!! I can borrow a gas tank of one of my many other i.c. engines.---Getting excited now!!!


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## jimjam66 (Aug 9, 2015)

I'm on the edge of my seat - is there anything more exciting than anticipating the first 'bang'?


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## Brian Rupnow (Aug 9, 2015)

Today's offering to the Machine Gods consists of a starter hub, the part which fits into my variable speed drill to engage the starter hub, and a mounted condenser. I have set the valve timing and the ignition timing. The ignition points and cam are hidden in behind the hub of the flywheel.


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## Brian Rupnow (Aug 9, 2015)

Now is the difficult time. The engine is ready to run. I have gas tanks which I can "borrow" from many of my other engines. The issue is that this type of engine has no throttle. It is designed to run "wide open" or "full throttle". The device which controls the RPM is the hit and miss lockout lever and the centrifugal governor. There is nothing that quite compares to starting one of these engines without the governor set up in place. First you wonder if it will start and run. Then, in one terrifying burst you wonder if you will be able to shut it off before it over revs and explodes. This all happens in a matter of nano-seconds, and it scares the crap out of you. I will make the lockout lever and install it before I try to start this engine. There is a spring required to control the centrifugal weight, and I think the spring I currently have in place is too light. I went to Brafasco and raided their spring collection, but the only spring that would actually fit the hole prepared for it is the spring out of a ball point pen. The strength of this spring is critical to the way the engine runs. If the spring is too light, the governor weight will fly out and engage the exhaust valve lifter at too low an rpm, and the engine won't have enough speed to keep running. If the spring is too strong, the governor weight won't fly out and engage the exhaust valve lifter until the engine reaches warp speed.    And the only way you will know if the spring is too light or too strong is to start the engine and find out!!! At least I have progressed from having to pull the spark plug wire off and risk electro-shock therapy. I have a kill switch on my "power box" which has the 12 volt coil in it.


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## Brian Rupnow (Aug 10, 2015)

So---How good are your eyes? In the first picture, the counterweight on the centrifugal governor has pivoted and swung outward from centrifugal force, causing the brass spool to slide along the crankshaft, which makes the hit and miss catch lever pivot and swing in under the 1/8" diameter split pin in the bronze valve lifter. This prevents the exhaust valve from closing, so the engine remains in the "miss" cycle as long as the engine rpm is high enough to keep the governor weight swung out like that. In the second picture, the engine has slowed down enough that the spring captured between the governor weight and the governor weight support has caused the governor weight to pivot and swing back in, which moves the brass spool the other way, thus causing the hit and miss lever to pivot the other way and swing out from under the split pin, which now lets the exhaust valve lifter  follow the cam and let the exhaust valve close to build compression as the engine continues to rotate because of the flywheel. In this state the engine will then fire and start the whole cycle over again. There is some very fussy work in getting all of this to happen freely in a static position.


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## Brian Rupnow (Aug 10, 2015)

FIRE IN THE HOLE!!!!  Engine is firing, but just as I suspected, the governor spring is too weak. It fires once, goes into miss mode and stays there. The weak spring doesn't have enough strength to retract the governor weight against even a low firing rpm!!


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## jimjam66 (Aug 10, 2015)

Brian Rupnow said:


> So---How good are your eyes?



I'll take your word for it ...


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## Brian Rupnow (Aug 10, 2015)

I have a fix for this, but it will take a while. The counterweight and counterweight support bracket are exactly as designed by the original designer, Philip Duclos, and the hole for the spring is only 0.172" in diameter. I can open this up to 0.219" safely, which will allow for a larger, stronger spring. Before I modify anything though, I will go back down to Brafasco and make sure they have larger stronger springs that will fit into a 7/32" diameter hole. Then I have to remove the flywheel, the ignition cam, and the crankshaft support bearing to get the counterweight support bracket off to work on it and enlarge the hole in it and in the counterweight.


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## Gerhardvienna (Aug 10, 2015)

Hi Brian
Maybe this will work for You?? Lay a shim at the shown place? 



Regards
Gerhard


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## Brian Rupnow (Aug 10, 2015)

Gerhard---the weak spring is on the governor, not the valve.---Brian


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## Swifty (Aug 10, 2015)

It's all looking great, although I can't make out where the governor spring fits, I know that you said it's a compression spring, so it's working to push the governor closed.

Paul.


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## Brian Rupnow (Aug 10, 2015)

I went to Brafasco and bought 3 springs that would fit into a 7/32" diameter hole in a "test piece" I had made. I got a light spring, a medium spring, and a heavy spring. I removed the governor and enlarged the hole that holds the spring to 7/32" diameter. Then I installed the medium spring (the copper colored one). For those of you who asked about the centrifugal governor, I have included shots of the governor bracket that is fixed to the crankshaft with a set screw, and the governor weight which swings out under centrifugal force to move the brass spool. You can see it before and after assembly. It pivots on a 1/16" diameter pin.


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## Brian Rupnow (Aug 10, 2015)

EXCELLENT NEWS!!! Engine starts and runs, but medium strength spring is still a bit too light. Engine is new, and still a bit stiff, so it dies before it can go from "miss" mode back into "hit" mode consistently. I am now changing up to strongest spring, but things are really looking positive!!!


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## Gerhardvienna (Aug 11, 2015)

Brian Rupnow said:


> Gerhard---the weak spring is on the governor, not the valve.---Brian



SORRY___My mistake:wall::hDe:
Good to hear it`s running, congrats!
Regards
Gerhard (waiting for some moving pics;D)


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## Mechanicboy (Aug 11, 2015)

Excellent done!  The next engine will be double acting oscillating engine?


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## Brian Rupnow (Aug 11, 2015)

No joy yet. The strongest spring does work all right (near as I can tell.) I had the engine running for short duration blasts, and grabbed the video camera a dozen different times but the engine wouldn't oblige me by staying running. I played with the ignition timing, first advancing it, then retarding it, looking for the "sweet spot" but never found it. I adjusted the carburetor needle to every conceivable position, but the best run I got was only about a two minute duration, with the engine gradually slowing down and coming to a stop. After about 50 different attempts to start the engine, I was rewarded with a rather ominous "clanking" sound every time it started. Nothing was visibly wrong that could be seen from outside the engine (and almost everything is on the outside of the engine.) The compression has improved exponentially, so the pressure caused by the engine firing has firmly seated the valves. I never reached the point where the engine "took off" and gained rpm until the centrifugal governor was activated, but I was able to activate it by spinning the engine fast enough with my 3/8" variable speed drill, so I know the centrifugal governor is working. I will pull the head off the engine sometime today and make sure that the piston isn't coming adrift from the connecting rod, and ascertain that my pressed together crankshaft hasn't slipped out of alignment.


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## Brian Rupnow (Aug 11, 2015)

TA-DA
[ame]https://www.youtube.com/watch?v=_j7U56CSLtI&feature=youtu.be[/ame]


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## Brian Rupnow (Aug 11, 2015)

I pulled the head off to check the piston, to make sure it hadn't come loose from the con rod but it was okay. I then seen that the set screws holding the flywheel and key in place had come loose, and that was what was making the nasty "clank" sound at the end of yesterday. I tightened them up and then I monkeyed with the ignition timing and fuel mixture some more. I advanced the spark more than I had tried yesterday, and I believe that is what finally did the trick. Now I have to try and suss out why it is not revving up. The flywheel is heavy, but that won't keep an engine from revving up. A heavy flywheel will only keep an engine from revving up quickly. I have noticed that the intake valve doesn't seem to be moving at all, although it must be moving some for the engine to run at all. I may try cutting half a coil from the inlet valve spring to see if that makes a difference.


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## Brian Rupnow (Aug 11, 2015)

Here we are going in and out of hit and miss mode. As I suspected, the spring on the atmospheric intake valve was too strong, making it difficult for the engine to draw in enough air (and consequently fuel) on the intake stroke. I removed the spring and cut off one full coil, and the engine immediately reached into a much higher rpm range with no other tweaking. The new higher rpm range allows the engine to go in and out of hit and miss mode, but it is running much too fast. I will now put the "medium" governor spring in place and see how much it slows the engine down.
[ame]https://www.youtube.com/watch?v=qymo4QU9d0Q[/ame]


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## Brian Rupnow (Aug 11, 2015)

We're done!!! This is the correct speed for a hit and miss engine to run at. Thank you to all who have followed this thread, and I truly do hope that any new-bees following may have learned something new.----Brian
[ame]https://www.youtube.com/watch?v=4Q1dWMnXfj0&feature=youtu.be[/ame]


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## jimjam66 (Aug 11, 2015)

That oscillating cylinder is SO weird to watch!  Fantastic work, the only question now is:  WHAT NEXT?


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## gbritnell (Aug 11, 2015)

Very well done Brian!
gbritnell


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## Gerhardvienna (Aug 11, 2015)

Great engine! This is a real good runner, gratulations!
Regards
Gerhard


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## Swifty (Aug 11, 2015)

Great job Brian, it was interesting to see the 3 videos and the difference that spring changes made to the running of the engine. The final video of it hitting and missing sounds great.

Paul.


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## barnesrickw (Aug 11, 2015)

This is an incredible engine.


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## Barnbikes (Aug 12, 2015)

Trying to imagine an inline engine. 3 or 4 cylinders all oscillating. Might have to make it a throttle governor though.


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## Cogsy (Aug 12, 2015)

Great work Brian - as always. I'll second what Swifty said about the spring changes. I think I'll play with the intake spring on my Rupnow engine (if I can get it back off my dad for a few days) and see if I can tweak the running/power to get more miss cycles in a row.


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## Roboguy (Aug 12, 2015)

Hi Brian, congratulations on completing an amazing engine! 

I am a complete newcomer to both this forum and the hobby, and this build thread is hugely inspiring and educational. Thanks so much for sharing. 

I love hit and miss engines, so this engine is definitely going on the someday maybe list! 

Cheers, 
James


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## Brian Rupnow (Aug 12, 2015)

Every time I build an engine, I discover something.--The thing about the engine refusing to continue running until I removed a coil from the intake valve spring was a "process of elimination" sort of deal. I knew I had spark. I knew the spark was coming at more or less the right time, or the engine wouldn't have run at all. I knew that I had fuel because I could see it moving in the transparent fuel line. I knew that the valve timing was right, or very close to it. The engine had reasonable compression---I could feel it.The sparkplug was good. This was a very typical problem that has plagued me and others before on these small i.c. engines. They start, they run, but only for 20 seconds or so and then they tail off as if they were running out of fuel. Too strong an intake valve spring (on an atmospheric intake valve) was all that was left. It couldn't suck enough air, and since it is the air movement that creates the vacuum to suck fuel up from the tank through Venturi effect, it was running out of fuel. This was an incredible find!!! Everybody that reads this will now be out in the shop dialing in their atmospheric intake valve springs!!!---Brian


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## toolznthings (Aug 12, 2015)

As always, very nice !!  Thm:Thm:Thm:

Brian


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## vascon2196 (Aug 13, 2015)

Great job Brian...I was there from the beginning and am happy to see such a great running engine.

I will be sharing this with my engineering students.


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## Mechanicboy (Aug 13, 2015)

Brian, how are the vibration of the oscillating engine?


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## Brian Rupnow (Aug 13, 2015)

Mechanicboy said:


> Brian, how are the vibration of the oscillating engine?



Probably bad, but I can't really tell. Every engine I build is screwed firmly to the wooden test bench with four #8 woodscrews, one on each corner. When you start an engine using an electric drill as I do, you absolutely do not want the engine to move. You don't want it to suddenly start and jump onto the floor, destroying months of work.I don't balance my engines. I build them, I run them, I video them,, and then they go "on the shelf". Different people have built the engines I design/build and complain because the engines "jump all over the place" when they are running. When someone posts a video of one of my engines running, not bolted down, and "walking" across the floor because of imbalance in the rotating assembly, I feel somewhat insulted. My mandate is to build an engine that runs. If someone wants an engine "balanced and blueprinted", then the onus is on them to look after that aspect of building the engine.----Brian


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## Brian Rupnow (Aug 14, 2015)

-It's funny how, as you solve the most common issues (poor compression valve timing), then you begin to focus on the OTHER problems. The first set of problems keep the engine from starting. Once you have solved the issue of getting the valves to seal, and your engine will actually start and run, then the second set of issues rears it's head----How to keep your engine running. And once you have your engines so they will start, and keep running, then you start wondering about the issue of "How do I get it to fire ONCE like the full size engines, and then immediately go into miss cycle for 8 or 10 revolutions, then hit again ONCE and repeat the cycle. My flywheel design boils down to "best guess". Right now, I think my flywheel is too heavy. There is simply too much inertia to overcome for that 1" cylinder to fire one time and bring it up to speed. The engine has to fire multiple times to bring it up to a speed where the governors will engage the miss lever. I don't believe it is an issue of the governor spring being too strong or too weak. I think the flywheel simply has too much mass for the bore of the cylinder. I'm not sure I will do anything about it, but I am wondering.---Brian


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## Brian Rupnow (Aug 15, 2015)

Guys--I truly do appreciate your comments and the fact that you stopped by and said Hi. I fully realize that to many veteran machinists, what I am making are just "nonsense toys". However, I find them exciting, and my machining skills improve with every engine I build.---Brian


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## Gerhardvienna (Aug 16, 2015)

Brian Rupnow said:


> ..........what I am making are just "nonsense toys". .................


Hi Brian
Isn`t that what we all do? Making expensive nonsense just for fun:hDe:
But I love it, spending time at the PC for planning and much more time at the workbench to build things up:fan:
At the time I`m NOT at the workbench, at that high temps above 35deg Cel. it`s much too hot for working, the next days will be cooler weather, so I can go on again.

.............and my machining skills improve with every engine I build.---
Absolutley correct!!!!!!!!!!!!!!
Regards
Gerhard


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## jimjam66 (Aug 16, 2015)

Brian, I submit that the bulk of the denizens of a forum titled 'Home Model Engine Machinist' are anything BUT veteran machinists and therefore we enjoy your build threads very much indeed!  Please don't stop on account a few who whine about things like vibration ... pretty please?


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## Roboguy (Aug 16, 2015)

Don't forget all us beginner's (I can't be the only one!) who learn so much and get very inspired by reading these threads. 

Brian, thanks again for taking the time to share with us all. 

Cheers 
James


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## Barnbikes (Aug 16, 2015)

Don't forget the dreamers who wish they could build something as cool as what you do.


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## Brian Rupnow (Aug 16, 2015)

JimJam--I wouldn't categorize people who complain about something legitimate as "whining".  Their complaints are real---The engines I build aren't balanced. They do "jump around" if they are not bolted down.  To be honest, it never crossed my mind that people would ever even attempt to start an engine which wasn't bolted down. Balancing engines is a kind of VooDoo art, that requires a lot of static balancing of parts and calculating weights of spinning assemblies before they are even made. There is a whole branch of science devoted to balancing rotating non uniform masses. I could do it---if I wanted to take the time to. Simply put, my engines are NEVER ran unless they are bolted down, so it's kind of a non issue for me. Those who do have a concern about it will have to balance the engines themselves. We have one excellent builder/poster from Australia that built the Rupnow engine #1 and then posted a video of it "walking" across the floor as it ran, due to it's out of balance condition. He posted a video of this because he found it amusing. He didn't do it to be negative, and he wasn't whining.----Brian


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## Cogsy (Aug 16, 2015)

Brian Rupnow said:


> We have one excellent builder/poster from Australia that built the Rupnow engine #1 and then posted a video of it "walking" across the floor as it ran, due to it's out of balance condition. He posted a video of this because he found it amusing. He didn't do it to be negative, and he wasn't whining.----Brian


 
Glad to hear this bit Brian - I certainly wouldn't want to insult you and you're right, it did amuse me. However with the rubber feet on a good non-slip surface the engine happily sits in one spot without being bolted down. 

As for vibration, sitting on my 2 stroke dirt bike and giving it a good rev gives a certain 'tingly thrill', that's almost naughty...


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## Brian Rupnow (Aug 16, 2015)

As a point of interest--I have been running the engine intermittently over the last few days searching for that "sweetest of sweet spots" where the carb setting and ignition timing are just about at the perfect spot. I have continued clipping half a coil at a time off the atmospheric intake valve spring, until I am at the point where I can barely feel any compression at all in the valve spring when pressing on the valve stem with my finger. (I have removed a total of 2 1/2 full coils since the engine first ran.) Each time I removed half a coil, the engine ran better.----Now, something I read about in regard to intake valves. I have always reamed the valve guide with an "on size" reamer, and turned the valve stem for a very precise fit in the guide. Of course, the more precise the fit is, the more drag is created on the valve when it opens and closes, and the more important perfect concentricity becomes between the valve guide bore and the actual valve seat. The piece I recently read said to make the valve stem about .001" to .0015" under-size from the bore of the valve guide. This removes any potential "drag" on the valve stem, thus allowing a more lighter and responsive valve spring. It also takes away some of the need for absolute concentricity between the valve guide and the valve seat.--The valve can "float" a little bit concentrically, ensuring a good seal between the valve face and the valve seat. I had inadvertantly turned the intake valve stem a bit smaller than I ususally do, but I thought of the article I had read and decided to use the valve anyways to see what would happen. It appears that the article was correct.


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## canadianhorsepower (Aug 16, 2015)

Hi Brian 
this is not to poke you but look at the stats
on almost 8000 of your likes given sucks. 
other peoples do great work and you don't even 
tell them "GOOD WORK" it's back fires

cheers


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## Swifty (Aug 16, 2015)

Brian, thinking about your comment on the clearance between the valve stem and guide, I always assumed a close fit was necessary to stop any air being drawn down in the gap, but this could probably be balanced by a slightly richer carburettor setting. It's only when you stop and think about these things that other ideas spring to mind.

Keep up the great work, how do you like the new mill with readout, are you planning you next project yet ?


Paul.


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## barnesrickw (Aug 16, 2015)

Why would somebody go through the trouble of even calculating stats like that if it were not intended to poke?  #transparent.


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## canadianhorsepower (Aug 17, 2015)

barnesrickw said:


> Why would somebody go through the trouble of even calculating stats like that if it were not intended to poke?  #transparent.




If this message was for me I didn't have to calculate the stats.
It's on your page by HMEM


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## Brian Rupnow (Aug 17, 2015)

Swifty--I love the new mill and readouts.The mill is very powerful, no more blown fuses and the readouts are just wonderful.  I wish that as Luc suggested, I had went for the 3 axis readout package. There is a readout on the Z axis which comes with the mill, but it is small, poorly lit, and difficult to read.---Brian


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## Brian Rupnow (Aug 17, 2015)

Luc-I didn't know it worked like that. Let me see if I understand this--I'm supposed to give lots and lots of "likes" to people so that I get lots and lots of "likes" in return?  There used to be a song about that "We belong to a mutual, Admiration Society".


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## Journeyman (Aug 17, 2015)

Hi Brian - Well I for one "like it", I have followed the whole thread with great interest including the spin-off milling machine saga. Thank you for taking the time not only to design and build such a novel machine but to make the extra effort to document the build in such great detail. 

As far as pressing the like button, well that sort of smacks of what the youngsters do on Twitbook or Facer to gain an imaginary army of friends!

Well done again, looking forward to the next project...

John


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## canadianhorsepower (Aug 17, 2015)

Brian Rupnow said:


> Luc-I didn't know it worked like that. Let me see if I understand this--I'm supposed to give lots and lots of "likes" to people so that I get lots and lots of "likes" in return?  There used to be a song about that "We belong to a mutual, Admiration Society".



Brian, 
plz don't get me wrong on this, it's nothing personal. But being in a teaching environment I've seen this more than you can think and I hate it. We are both member on another group and the discussion have been going on for over a year to have a straight "LIKE" button. I kind of feal bad when I see peoples building your "personal engine plans AND FREE" and then complaint cause it vibrate:wall::wall: 
All I can say is Keep up the great work, nice design and they always work Thm:Thm:Thm:
and I must say You have the BALLS to design them from scratch 

and other will ***** at them from scratch


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## Brian Rupnow (Aug 17, 2015)

The engine is running good. Very good!! I have everything dialed in now to the point where I don't see much room for improvement.---BUT---The engine still has to "hit" 4 times consecutively before it ramps up enough speed to go into "miss" mode. A weaker governor spring won't fix this. With a weaker governor spring, the engine will go into "miss" mode immediately, and  not build up enough speed to keep going and "hit" again. A stronger governor spring will make the engine run faster, but not do a lot in terms of hit to miss ratios. I have to get rid of some of the mass in that flywheel. Right now, as it sets, the flywheel weighs 3.2 pounds, and of that 3.2 pounds, 2.72 pounds is in the outer rim. If I set the flywheel up in the lathe and carve away the inner surface of the rim by 33% of the existing thickness on both sides, the rim will then weigh 2.15 pounds.-This equates to a reduction in mass of roughly 21%.---In fact, since I have to remove it from the chuck and turn it around to machine the other side, I can even try it on the engine at the "half way" point where I have only carved away 10.5% of the existing mass. On one hand, I hate to carve up a reasonably pretty flywheel. On the other hand, it didn't cost me anything but my time, and I really would like to have a hit and miss engine that hits once, misses for 5 to 8 cycles, then hits again.


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## bazmak (Aug 17, 2015)

It seems simple why not remove say 5% at a time and note any
improvements then we can all have feedback


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## Brian Rupnow (Aug 17, 2015)

Bazmac---Mainly because I don't expect changes at the 5% level. 10%--maybe,20% very probably.


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## Charles Lamont (Aug 18, 2015)

Isn't the most effective way to reduce the flywheel's moment of inertia going to be to reduce the outside diameter?

Have you tried how it responds under load?


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## Brian Rupnow (Aug 18, 2015)

Charles Lamont said:


> Isn't the most effective way to reduce the flywheel's moment of inertia going to be to reduce the outside diameter?
> 
> Have you tried how it responds under load?


Charles--You are correct about the outer rim of the flywheel doing most of the work. that is why I am reducing the weight of the outer rim. I have applied a load to the engine while it runs (by applying thumb pressure against the flywheel)----This makes it "hit" continuously, with no "miss" cycles.


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## Brian Rupnow (Aug 18, 2015)

Positive results--With one side of the outer rim machined as per my previous post, (removing approximately 10.5% of the rims weight), the engine now fires 3 times before it goes into "miss" mode. It was firing 4 times before going into miss mode before I machined one side of the flywheel. The flywheel is now back up on the lathe, removing the same amount of material from the other side.


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## Brian Rupnow (Aug 18, 2015)

With the other side of the flywheel machined away, for a total weight reduction of about 21.5%, I don't at this time see a heck of a lot of difference in the hitting and missing. BOO---HISS!!! This engine has totally different characteristics than my water cooled hit and miss engines. The water cooled engines stay very stable in their set-up demands, requiring that the fuel mixture needs to be slightly leaned out as they warm up, but that is all. This engine gets hot.---Hot enough to burn my fingers with the cylinder. And as the heat gradient changes, so do the set-up parameters. I now have to wait half an hour for it to cool down completely before I mess with it anymore. One thing I know---The little 1/16 cross section x 1/4" i.d. o-ring that I have between the oscillating cylinder and the support bearing is only butyl rubber, and it is probably degrading very rapidly from the exhaust gas passing over it. I may go over today and get a Viton o-ring to replace it. That may help the engine stability.


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## Brian Rupnow (Aug 21, 2015)

I've spent the last few days studying relationships!! No, not that kind of relationships, ya dirty buggers!! The relationship between engine speed, flywheel weight, and governor spring strengths. The heavier a flywheel is, then the greater a "kick" it needs to bring it up to a speed fast enough for the governors to come into play. That is why my engine had to fire five or six times in a row, each time giving another kick to the flywheel until it was spinning fast enough to trip the governors. At this time there were two ways I could have gone--#1-A lighter governor spring, or #2-a lighter flywheel. I chose to go with the lighter flywheel option, and after much dialing and tuning and disassembly/reassembly, I have it tuned to a point where my engine fires only two and sometimes 3 times before the flywheel is going fast enough for the governors to kick in. Also, I note that with the lighter flywheel, the engine runs at a faster speed than previously. I could shave some more weight off the flywheel, but then we get into the opposite side of the equation--The flywheel has to be heavy enough to carry the engine through 5 or 6 "miss" cycles, and still have enough inertia to compress a charge of fuel for firing after the governors disengage.  I don't want to take more off my flywheel and have it too light. It is a lot easier to take metal off than it is to put it back on. Another option comes into play here, that I'm thinking about. The faster the flywheel is running, then the closer it is to the governor "trip point", and the less "kick" it needs to speed up to trip the governors.---However, that defeats the "I want my engine to run slowly" side of things. It's easier for me to change the governor spring than it is to remove and machine more off the flywheel, and at least with changing springs it is easier to "undo the change" than it is if too much weight is taken out of the flywheel.


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## Brian Rupnow (Aug 21, 2015)

I am getting very encouraging results by cutting off one coil at a time from the governor spring. The good news is that it is a standard spring from Brafasco, and if I cut it back too far, there are many more of the same where it come from.


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## gbritnell (Aug 21, 2015)

Brian,
As you stated the flywheel mass needs to be great enough to overcome the compression on the compression stroke. There was mention of increasing the compression to give the engine more power but if you were to go that route then you're increasing the problem that you already have. An engine will run probably all the way down to about 4:1 compression. It's not all a matter of ratio but of cylinder/piston sealing. I don't know what your designed compression ratio is but by possibly reducing it you accomplish what I stated in the first sentence. This would just be a matter of making a piston with less material above the wrist pin. It's much easier to make a piston than to take too much off the flywheel and then have to make another. 
gbritnell


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## grapegro (Aug 21, 2015)

Hello Brian,
                Working from memory, the govenor system you are using is a sliding block or sleeve. When you shorten the goveror spring, could it be that there is a sideways effect that could not allow the sliding movement freedom
Norm


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## Brian Rupnow (Aug 21, 2015)

As designed, this engine has 4.5:1 compression ratio. Norm--the governor spring sets in a cavity between two hinged pieces.


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## Brian Rupnow (Aug 26, 2015)

One final video before I leave this thread behind. I added an anti-backflow valve into the fuel line and shaved away close to 50% of the original flywheel rim thickness to get to the state you see in this final video. ----Brian
[ame]https://www.youtube.com/watch?v=oBSHanHaSRU&feature=youtu.be[/ame]


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## canadianhorsepower (Aug 26, 2015)

Like you say a little bit fast:hDe:
but by the sound of it, it's pretty stable on the number
of hit and the number of miss Thm:Thm:

Cheers


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## ShopShoe (Aug 27, 2015)

That was quite a project to follow.

As always, thanks for posting the design process with explanation, the machine and build process complete with a rethink or two, then the excellent video of another fun-to-watch running engine.

I also enjoyed the detour as you got your new mill set up.

--ShopShoe


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## Brian Rupnow (Aug 27, 2015)

Thought for the day---Imagine a rock, tied to a 10 foot length of string. Hold one end of the string in your hand, and swing the rock around in a horizontal plane. Once you get it going, you can swing that rock pretty darn slowly, and it will keep the sting tight and maintain it's position. Change up to a five foot length of string. You can still keep the rock swinging, but you are going to have to swing it faster to maintain a tight string and keep the string horizontal. Probably not twice as fast, but definitely faster. Now change up to a 1 foot length of string. It becomes impossible to swing the rock fast enough to keep the string tight and horizontal. Whatever forces are at play here, are probably not linear. The same physics apply to model hit and miss engines. My model is a 1" bore with an approximately 5" diameter flywheel. Let's just for the heck of it, translate that to a 3" bore. That would correspond to a 15" diameter flywheel. I don't have a full size 3" bore, single flywheel hit and miss engine here to measure, but I'm pretty darn certain that the flywheel on such a model would probably be at least 24 to 30" diameter. Not everything is scaleable. I did get the engine to slow down some by retarding the ignition a bit, but not a lot slower.---Sure has been fun though!!!


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## Brian Rupnow (Aug 30, 2015)

If anyone decides they would like to have a go at building this engine, then send a request to the email address in my web page (not the forum email) and I will send you a free set of my working drawings which are in Imperial (inch) dimensions.---Brian


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## jimjam66 (Aug 31, 2015)

That's a very generous offer, Brian!  Thanks again for all you do for us amateur engineers.


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