# Brians Radial Engine



## Brian Rupnow (Oct 4, 2009)

I think the time has come!!! I have built 5 single and double cyl. engines, with and without valves. Now for something a bit more challenging.--I really like the Hula engine as designed by Philip Duclos. I think perhaps I will design and build something similar. Follow along if you like. This should be very interesting. Please note that I have never seen the plans for this engine.---only the YouTube video of it running. All designwork you will see on this build originates with me. It is not my intent to rip off nor plagerize someone elses engineering work.----This solid model is my "begining concept"---It will change as I go along and get deeper into it.--- Brian


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## Krown Kustoms (Oct 4, 2009)

Nice, Im on the wagon.
-B-


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## black85vette (Oct 4, 2009)

Arranging all the connecting rods on the crank would drive me crazy. Looks like a fun one.

So what contraption are you going to drive with this one??  ???


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## BAH101 (Oct 4, 2009)

Hi Brian, its gonna look nice with all the rest of your engines. On a IC radial, they use a Master Rod, similar to the pic (I hope gets inserted). This is a 7 cylinder master, but I think you will understand where I am coming from.


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## Brian Rupnow (Oct 4, 2009)

black85vette  said:
			
		

> Arranging all the connecting rods on the crank would drive me crazy. Looks like a fun one.
> 
> So what contraption are you going to drive with this one??  ???



Jeez----Give me a break!!! It will be enough of a challenge to make this work without worying about what to drive with it. Besides---It will be kinda like the beam engine. There will be enough monkey motion going on with just the operation of the engine.---Its not going to need to run anything else.


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## Brian Rupnow (Oct 4, 2009)

Should ought to look something like this when it runs----


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## Cedge (Oct 4, 2009)

Brian
That is among the most mesmerising engines you'll ever watch run. The cylinder motion is almost organic. The Duclos version has 6 cylinders and is a messy little monster, slinging oil to all points of the compass. You might find you want to give the exhaust ports a bit of directional assistance....

Steve 
The guy with a Dalmatian spotted T-shirt ala Duclos.....(grin)


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## lathe nut (Oct 4, 2009)

Brain if you are going to do that I know its a done deal in your mind,you have built all the parts and see it running all in the minds eye, how about if you rest someday can I borrow your brain, you have enough projects to keep all of going for several years, so looking forward to this one, thanks again for sharing, Lahte Nut


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## Cliff (Oct 4, 2009)

Hey Brian looks like a fantastic build sounds exciting I will be following along watch a great build. Cliff


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## Brian Rupnow (Oct 5, 2009)

All of the cylinders, pistons and connecting rods are identical.--However, the main frame which holds everything does get pretty strange---


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## black85vette (Oct 5, 2009)

I have no idea if it would work for a wobbler configuration, but could you use a plate for all the pistons to connect to on the same geometric plane like the radial in this picture?

http://en.wikipedia.org/wiki/Radial_engine


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## kvom (Oct 5, 2009)

So to keep the connecting rods identical you need to offset each cylinder.


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## Brian Rupnow (Oct 5, 2009)

Okay---This is the configuration using a seperate hub which all the con-rods connect to. The cylinders are not offset, and the cylinders are all fixed position with one "master rod" attached rigidly to the conrod hub. It works--I have "proven" that with the attached animation. Right now I'm going bananas trying to see if this is adaptable to oscillating cylinders. It is bending my head quite a bit trying to figure this out. If I can use this method with oscillating cylinders, I would prefer to. Its just that I've never actually seen it done this way with oscillating cylinders. The beauty of oscillating cylinders is that there is no valve train to be concerned with, as the oscillating action of the cylinders provides the valving.


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## putputman (Oct 5, 2009)

kvom, this is kind of an ugly version of Brian's stepped concept. It does work well. 
To eliminate all the external plumbing required to run several cylinders, I machined a labyrinth of grooves on the back side of the frame and then sandwinched them with a back plate.
Also made the cylinders double acting by capping the open end.


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## Brian Rupnow (Oct 5, 2009)

Damn!!!--I think I can make this work---


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## black85vette (Oct 5, 2009)

th_wav woohoo1

Looks great.


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## Brian Rupnow (Oct 5, 2009)

Can it really be this easy??? Everything SEEMS to work okay in the solid model. I may be all wet here, but I guess the only way to tell will be to go ahead and build it.





View attachment ASSY-BRIAN RADIAL NEW TRY.PDF


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## Brian Rupnow (Oct 5, 2009)

And Cedge---Thanks a million for the phonecall. That was very thoughtfull of you. like I said---If I get this thing all built and it doesn't work, I may call you back to get help scraping the egg off my face!!!---Brian


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## Brian Rupnow (Oct 5, 2009)

This seems to be the most complex part, so I will start with it. Don't copy this, as it will probably have errors and changes in it as I go along. I will post a revised and corrected drawing when the engine is running properly. I just wanted to give you a preview of what I will be working on as we go along here.





View attachment MAIN SUPPORT FRAME-RADIAL-NEW TRY.PDF


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## eskimobob (Oct 5, 2009)

Looking forward to following ths :bow:


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## Brian Rupnow (Oct 5, 2009)

I took a look through my aluminum scrap stockpile and of course, as luck will have it, I didn't have any 1/4" plate.--So---I used a peice of 3/8" material. (I will flycut it down to 1/4" thick.) I have layed out the overall outlines with a scriber and compass and protractor. The black marker is only there to make things show up in the photograph. You will also see that I have marked one side of the plate as "good side" in marker---thats to make sure all my measurements are taken fron the same side of the plate. My little milling vice will only open to about 2 7/8" wide, so I will use a peice of "sacrificial" aluminum plate and clamp this plate directly over it to my mill table to drill all the holes in it. While I have it clamped down I will also drill the five 9/16" diameter holes in the crotch of all 5 spokes to form the 0.281" radii between them. I will flip the plate over and flycut the far side to prevent milling away all my layout lines. After all the holes are drilled, I will use the bandsaw to cut the material away from between the spokes, then stand the plate up in my mill vice to drill the 1/16" holes thru from the ends of the spokes to the center air annulus.


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## rickharris (Oct 5, 2009)

Like this one you mean? http://npmccabe.tripod.com/3sisters.htm sounds good.


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## Mike N (Oct 5, 2009)

Brian,

What keeps the connecting rod hub from getting ahead or behind the crankshaft rotation? That's why all radial engines have one master connecting rod. 

Mike N


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## black85vette (Oct 5, 2009)

Not trying to answer for Brian. (I'm not that smart) But in looking at his design it has a major difference. Its ports are timed by the motion of the cylinder not specifically relative to the crank. In a real radial engine it would be more critical since the valves have to be in time with the crank and cam. Running a little ahead or a little behind the crank may not really matter to an oscillating engine.

I am willing to be wrong here and won't take a bullet fighting for my opinion, but that is how it looks to me.


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## doc1955 (Oct 5, 2009)

But without a master rod they will all advance and I don't see it working (just my thought) I could be wrong have been a time or two in the past :big:
Now if the cylinders were stationary and slide valve were used it I feel would work just fine say a rotary slide valve in the on the back side.


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## Mike N (Oct 5, 2009)

Mike N  said:
			
		

> Brian,
> 
> What keeps the connecting rod hub from getting ahead or behind the crankshaft rotation? That's why all radial engines have one master connecting rod.
> 
> ...


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## black85vette (Oct 5, 2009)

Should not take much to make one of the pistons the master rod.  May make the timing a little different since the plate will be rotating a little bit back and forth with the master rod rather than maintaining a fixed orientation.


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## Brian Rupnow (Oct 6, 2009)

You fellows can't tell from the drawing, but the con rod on the top vertical cylinder is the master rod. It will be silver soldered to the rotary hub. All of the other rods pivot at the rotating hub.---Brian


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## Brian Rupnow (Oct 6, 2009)

First stage of drilling completed. It doesn't look like much, but there are 25 drilled holes in that puppy!!! There is a peice of "sacrificial" aluminum plate underneath the plate being drilled, so that I don't drill into my mill table. ---And don't get alarmed if some of the holes aren't perfectly on my layout lines. Remember, those lines were scribed by hand using an old drafting protractor, and were a visual reference only.--All the holes were drilled using ordinate measurements taken from the center hole, using the dials on the x and y feed of the mill.


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## cfellows (Oct 6, 2009)

Looking good, Brian. How did you calculate the ordinate positions of the holes while doing the drawings?

Chuck


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## Brian Rupnow (Oct 6, 2009)

cfellows  said:
			
		

> Looking good, Brian. How did you calculate the ordinate positions of the holes while doing the drawings?
> 
> Chuck


Chuck--You missed a post.--Look back on page #2--the drawing is there.


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## Brian Rupnow (Oct 6, 2009)

I had a slight change of plan--I decided that since I was planning to use the lathe anyways to put the annular air passage in the back side of the main frame, I might as well use the lathe to cut my plate down from 3/8" thick to 1/4" thick. I drew another circle with my old drafting compass about 1/2" greater in diameter than my greatest part dimension and rough cut it out on my bandsaw. I have a hub/fixture left over from another job that has a very convenient 0.375" stub on the face and is tapped fro 5/16" bolts and also has some 5/16" clearance holes though it. I mounted the 3/8" reamed hole in the center of my plate on the stub and bolted it to the face of the hub, then set it up in my lathe and turned the outer diameter to be concentric with the hole in the center. (You will see in the next post that I had to slot one of my 9/16" clearance holes to pick up the hub bolt pattern, but thats okay---I took the material out of one of the webs that will be cut away between the spoles.) Here is a picture of the step just described, and of the hub/fixture.


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## Brian Rupnow (Oct 6, 2009)

I then reversed the jaws in my 3 jaw chuck, mounted the plate as shown, and then turned the plate to 1/4" thick in the area I needed it to be 1/4" thick. I also ground an old cut off tool to a vicious looking point and plunge cut the annular groove.


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## Brian Rupnow (Oct 6, 2009)

Here we are drilling the air galleries that reach from the end of the arms to the center annulus. This was a bit trickier than I anticipated. My mill soesn't have enough headroom to hold my precision chuck and the main chuck and a 1/16" diameter drill.--And besides, my 1/16" drills weren't long enough!!  I hunted around and found an 0.075" drill, and used it to drill into the end of a 1/8" diameter rod in the lathe, silver soldered it in place in the end of the rod, then chucked it up in my main chuck (which won't hold anything smaller than a 0.105" dia drill because it won't close enough to grip it). Also, you can see how I inserted some 1/8" diameter rods thru the reamed holes in the part being drilled to level it in the milling vice.


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## Brian Rupnow (Oct 6, 2009)

And Voila'---we have a pretty shiny starfish. This part is complete now. I have showed the front side and the rear so that you can see the annulus that distributes air out the 5 spokes.


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## ariz (Oct 6, 2009)

Brian you solved well the setup problem with this piece and the result is very nice
go on with the build, and thanks for sharing


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## Brian Rupnow (Oct 6, 2009)

I think I will build the stand next. I originally had it made from an angle, but realized I couldn't machine the annulus on the lathe if did that.


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## ozzie46 (Oct 6, 2009)

Brian, Great job.

 If you meant your last plan post to be a .pdf file, it didn't make it.

 Ron


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## Brian Rupnow (Oct 6, 2009)

ozzie46  said:
			
		

> Brian, Great job.
> 
> If you meant your last plan post to be a .pdf file, it didn't make it.
> 
> Ron


Ron--I didn't plan it to be a .pdf---Mainly because the drawings as well are a 'Work in progress". I don't want folks downloading and saving drawings untill I have made revisions as necessary as the work progresses. I will post all the drawings for this as downloadable .pdf files once the engine is running and all drawings have been corrected.---Brian


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## Brian Rupnow (Oct 6, 2009)

This is not a "milestone" post.---Rather I have posted it because I'm so damn proud!!! I FINALLY GOT TO USE MY ROTARY TABLE. I had planned to cut the air annulus in this part on my lathe, but decided at the last minute to use my rotab. I paid a lot of money for it when I bought it 2 years ago, and I have only ever used it once before, to cut spokes in a flywheel for my twin cyl. horizontal engine. It works very well for the operation I just performed, and I feel so good about it I had to take a picture. You will also see that as I got part way thru the operation, I had to stop and cut a clearance in the hold down strap to allow me to cut to the depth I needed.


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## ozzie46 (Oct 6, 2009)

No problem Brian, Just checking. Thm: Thm:

  Ron


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## Brian Rupnow (Oct 7, 2009)

So---Now we have the main body finished and mounted and the center brass bushing in place. Its just mocked up for a picture right now. After lunch I have to do a little creative gasket making to keep air from leaking between the "star" and the vertical support. Then its time to start with my cylinders.


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## Brian Rupnow (Oct 7, 2009)

I spent this afternoon making and installing a gasket, machining an air inlet tube, the crankshaft, and a bronze flywheel. I machined the crankshaft from a solid peice of 7/8" diameter shaft, with the most of it turned down to 1/4" diameter. Why---well, partly because I'm a masochist, and partly because I don't know how much vibration there is going to be with this engine, and I didn't want a built up crankshaft flying apart. Interesting story about the peice of bronze that I used for a flywheel---my old neighbour gave it to me. He says he has had that peice of bronze since just after the Korean war. Apparently it was part of the guidance system in a torpedo?????? I also stopped by my metal supplier and picked up the material to make my cylinders and pistons and connecting rods from.---will start them tomorrow.


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## Brian Rupnow (Oct 8, 2009)

This morning I got up and machined the connecting rod hub. And yes, the one "master rod" will be siver soldered to this hub. Come on, talk to me people, if you are interested in this build. I feel like I'm posting in a vacuum here. I do intend to post all the detail drawings for this once its working.---Brian


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## Krown Kustoms (Oct 8, 2009)

Looks good, I am still trying to figure out where I have seen this type of engine before.
I have seen it in person but cant remember where.
I haven't been to an engine show yet.

Does the center hub work as an eccentric?

-B-


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## cfellows (Oct 8, 2009)

Sorry for the silence, Brian. However, I always check out your progress first thing when I log on. And I do understand that a lot of our motivation for posting pictures is in the comments received.

I am amazed at how fast your projects proceed. I think the main difference between you and I is that you have a good set of working drawings before you begin and I kind of make mine up as I go along. My process is definitely slower than yours!

Does your cad software have the option for automatic ordinate distances? If I were drawing something like a radial engine, I would tend to use polar coordinates and angles from the center. Not sure how I would get that converted to x-y positions...

Chuck


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## Brian Rupnow (Oct 8, 2009)

Krown Kustoms---Many older propellor type aircraft had radial engines. The hub is not an eccentric--the ecentric is at the end of the crankshaft. The hub orbits --its very difficult to explain. Look at my animation post that says "Damn---I think I can make this work". Chuck---You are so right!!! It is the dialogue with all the other people out there that makes this fun and keeps me motivated. When nobody answeres my posts, I start to feel like nobody is interested. When I make drawings I can choose whatever type of dimensions I want to use. There is an "automatic" dimensioning sequence I can choose, but it puts so many dimensions on the drawing that I could go crazy looking at them all. All I have to do is select where I want the dimensions to appear, between which edges, and the software puts them there, one at a time. That way I have control over what type of dimensions are used and where they go. Since I "grew up on a drafting board", and only moved into computer world about 12 years ago, I tend to use a combination of outline dimensions and ordinate dimensions. As far as how fast I do things---Thats only because I have no real work these days, so I can work 8 hours a day on this stuff. If the friggin economy ever comes back, I'll probably be so busy doing "real" work that I will have no time to build model engines.----Brian


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## Captain Jerry (Oct 8, 2009)

Brian

It looks like you are heading down the right track. That engine ought to run just fine. I like the change from staggered pistons with individual connection to the crank to the hub with master rod. I have looked at the staggered design in the past and it just didn't look good to me. I like symmetry. 

Will the valve positions for the cylinders all be the same? I haven't plotted it out but it seems that the cylinders with the free connection might have a slightly greater wobble angle than the one with the master rod. Even if they do, it may not make any difference to the port positions.

Keep it up. I want to see that hub spin. Most radial engines hide all that action in the crankcase.

Jerry


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## black85vette (Oct 8, 2009)

Good stuff Brian. Lot's of us watch the project with great interest, but may not have much to add. Had a guy on one of my Corvette forums that responded to every post he read. But most of his posts were just  or Thm: I think he had a total number of posts around 25,000.

I also wonder about the timing with a master rod. Does it make the other cylinders time a little different? I assume your software models this and places the ports appropriately. Is that right?


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## Brian Rupnow (Oct 8, 2009)

Thanks for the responses guys. As far as the port timing, My solid model tells me that either there is no difference between the master rod timing and the other 4 cylinders, or else so little difference that it shouldn't make any difference. I won't really know myself untill I go to run this thing.


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## tel (Oct 8, 2009)

Brian Rupnow  said:
			
		

> When nobody answeres my posts, I start to feel like nobody is interested.



I'm watching with interest Brian, but, so far, nothing really to add.


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## kvom (Oct 8, 2009)

Since I am working on the Halo engine, also a 5-cylinder radial, I have been following this build as well. The Halo has fixed cylinders with pushrod valves operated by cams, so quite different in design.


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## Brian Rupnow (Oct 8, 2009)

This afternoon wasn't as productive as I would have liked. First off, I thought my mill was out of tram. After multiple checks, I established that my mill table is in perfect tram, but my (cheesy) tilt/twirl/swivel vice is out of tram by 1 thou from right to left over the width of the 3" jaws. I decided that was within acceptable limits for the work I do, but it still consumed an hour doing all the checks. Then my wife started making unreasonable demands about cutting the lawn one more time this year before the whole fam damily comes for thanksgiving this weekend, so that burned another hour---and tomorrows garbage day, so had to do the big garbage gather and load up the blue (recycle) box. -------I really hate being environmentally friendly---Liked it much better when I was a kid---anything organic went to feed the pigs---anything that could be burned was set on fire in the back yard---and anything left was thrown down over the bank into the swamp!!!. (and if you're wondering, no, I'm not a member of Greenpeace.)-----Anyways, I built my first connecting rod. An inordinate bunch of work for such a little darn thing. First step--turned a peice of 5/16" diameter brass to 1/8" and 1/4" diameter in the lathe and used a #5-40 die in a tailstock mounted die holder to thread it.---Forgot to take a picture!! Second step--Over to the mill to drill and ream cross hole in end of rod.


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## Brian Rupnow (Oct 8, 2009)

Without changing my set-up, I milled the flat on one side of the rod---


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## Brian Rupnow (Oct 8, 2009)

Flipped the rod around 180 degrees and stuck a peice of 1/8" diameter rod in the reamed hole and used my level to make sure that it was setting at the correct angle of rotation---


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## Brian Rupnow (Oct 8, 2009)

Then milled the flat on the second side of the rod.---I'm not sure if this is the correct way to do this, but it is the best I could figure out without having to buy more tooling.


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## Brian Rupnow (Oct 8, 2009)

And, as I said in an earlier post, the master rod gets pinned, then silver soldered to the hub.---Yes, I'm a messy silver solderer---but once its filed, sanded, and polished, nobody will ever know. ---I did use a 3/16" drill and put a chamfer in the outside of the brass hub so that when I remove all the excess silver solder there will still be a ring of it left all around the 1/8" diameter pin. This silver soldering will be on the side of the hub that doesn't show when things are assembled.


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## zeeprogrammer (Oct 8, 2009)

This is getting more interesting. I was reviewing the thread and some of the videos and pictures got me thinking.

When I first started this wonderful hobby last February...I got a casting kit for a Model #2A (wobbler). Messed that one up and got a 2nd. Then a 3rd and then a 4th. Finally got the thing built and running. My first engine!!!

Anyway...I now have the 'parts' for 3 additional wobblers...and hopefully some improved machining skills. So I'm thinking...why not build a radial out of them?

So like I said...this is getting more interesting and I'm learning a lot on this thread.


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## Groewrs (Oct 8, 2009)

Looking good, Brian!

That's the way I would have milled the connecting rod. One day I'll invest in some collets and collet block...

Like most others here, I enjoy following your progress. At least one of us is achieving something in the workshop 

Gordon


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## Kermit (Oct 8, 2009)

When it comes to soldering of any kind... just remember this.

The Bigger The Blob, the Gooder the Job.



 :big:

I heard that so long ago I can't remember who said it, but it still gets me smiling to this day. 

Kermit


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## cfellows (Oct 8, 2009)

Brian, you're like the Eveready Bunny. I'm plum tuckered out just watching your progress!


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## Deanofid (Oct 8, 2009)

Going great guns, Brian. You're a real terror when it comes to makin' chips!




			
				Krown Kustoms  said:
			
		

> Looks good, I am still trying to figure out where I have seen this type of engine before.
> I have seen it in person but cant remember where.
> -B-


Phil Duclos came up with it. He called his the Hula Hula engine. 
Looks like this one, but six cylinders. I have prints for it, I think,
along with some for a similar three cylinder.


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## Cliff (Oct 8, 2009)

Hey Brian I think that all your builds are awesome and am inspired with the way you make up the prints and then build the engine I always had to build what ever I was doing and then draw the prints. Keep up the good work. Cliff


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## Brian Rupnow (Oct 9, 2009)

Five good little cylinders "to be"---and one really, really BAD little cylinder "not to be". And yes, thank you very very much---I AM AWAKE NOW!!!! Now I am off to do the (shudder) vacuuming, and helping good wife to clean house up for impending Thanksgiving guests.


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## Bill Mc (Oct 9, 2009)

Happy Thanksgiving Brian (and your family). P.S. I still have that visit to make.


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## black85vette (Oct 9, 2009)

Ouch. Bet that was exciting.

Happy Thanksgiving.


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## cfellows (Oct 9, 2009)

So, was that a milling cutter that grabbed ahold of the bad little cylinder?

Chuck


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## Brian Rupnow (Oct 9, 2009)

That was the result of a "Stupid Attack""!!! My cylinders are exactly 1/2" wide. I haven't got a chamfering milling cutter yet, so I cocked my 'Tilt/swivel/gyrate vice over to 45 degrees to cut the chamfers. I THOUGHT I had a 3/8" wide parallel under the cylinder to bring the edge I wanted to chamfer up above the vice jaws.--It was a 1/2" wide parallel. The vice locked up on the steel 1/2" parallel, and as soon as the cutter hit the brass (which was not locked anywhere near as tight as the parallel) the cutter pulled it up. and stalled the mill. I then went upstairs, put on clean underwear ;D ;D ;D, and made sure I had a 3/8" parallel in there for the rest of my chamfering.


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## Brian Rupnow (Oct 9, 2009)

Figuring it out as I go along.---I didn't know just how I was going to cut the relief area on the cylinder (highlighted in pink in the model.) After a bit of head scratching, I reground a carbide tipped boring tool to be flat across the tip with a 7 degree relief angle on the back side, turned the boring tool so that it sets at 180 degrees to its normal position in the holder, and ran the mill in reverse!!!---It worked like a charm!!! I still have to do a set up on the lathe to turn the diameter on the end.


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## vlmarshall (Oct 9, 2009)

Very nice! ;D
I was just talking with someone yesterday about the usefulness of a boring head.


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## Brian Rupnow (Oct 9, 2009)

One down, four to go. I'm not sure why I have the chatter marks. I tried running the lathe at 550 RPm and at 970 RPM---didn't seem to make much difference. It might be my hand ground HSS tool, or maybe I should be running the lathe faster?


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## kvom (Oct 9, 2009)

I usually turn brass stock that size at ~600 rpm.


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## Brian Rupnow (Oct 9, 2009)

Now I understand why I see some people building "Vice stops". I wish I had one today.--Multiple set-ups for these cylinders would be so much easier if I had a second "fixed reference surface" other than the fixed jaw of the vice. This is almost the first time I have had to build multiple parts the same. I say almost, because when I built my twin horizontal engine, there were two con rods, and valve rods.


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## Deanofid (Oct 9, 2009)

Brian Rupnow  said:
			
		

> One down, four to go. I'm not sure why I have the chatter marks. I tried running the lathe at 550 RPm and at 970 RPM---didn't seem to make much difference. It might be my hand ground HSS tool, or maybe I should be running the lathe faster?



Your lathe tool for brass is flat on the top, right Brian? The only clearance you want on a turning tool for brass is on the front (side facing the head stock) and on the end, (end of tool, facing work). Top surface should be completely flat. And yes, you can run the lathe pretty fast cutting brass.


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## Brian Rupnow (Oct 9, 2009)

Deanofid  said:
			
		

> Your lathe tool for brass is flat on the top, right Brian? The only clearance you want on a turning tool for brass is on the front (side facing the head stock) and on the end, (end of tool, facing work). Top surface should be completely flat. And yes, you can run the lathe pretty fast cutting brass.


Thanks Dino---I didn't know that. I just used the same tool as I use on mild steel and aluminum.


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## Deanofid (Oct 9, 2009)

Brian, here are a few pics of a good brass cutter for the lathe. The degree of the angles is not critical. Mainly, the top needs to be flat.
























I find it hard to make good photos of tool edges due to lighting reflections. Hope these are of some use.

Dean


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## kvom (Oct 9, 2009)

One way to have a quick vise stop is to press a parallel against the sides of the jaws and then press the work against the parallel while tightening the jaws.

I'm able to use a lathe bit with top relief on brass without difficulty. Perhaps it's because my lathe is more rigid than yours.


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## spuddevans (Oct 10, 2009)

Brian Rupnow  said:
			
		

> Now I understand why I see some people building "Vice stops". I wish I had one today.--Multiple set-ups for these cylinders would be so much easier if I had a second "fixed reference surface" other than the fixed jaw of the vice.



You might well have a vice stop and not realise it. This is what I use until I get round to making a "proper" one.






Just make sure you clamp it on the fixed jaw ( dont ask me how I know that :big Works a charm for me.

Tim


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## Cedge (Oct 10, 2009)

Kvom
That top relief is giving you more problems than you might think. It's not the rigidity of your machine that is a factor as much as it is the fact that a raked tool grabs and tears brass rather than cutting it cleanly. It's just the nature of the material. You'll get a nicer finish with the flat top cutter. After hand polishing more than a few miles of brass, I can definitely attest to the difference.

Steve


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## Brian Rupnow (Oct 10, 2009)

Okay boys and girls--Here we go. I have built all the parts on the following drawings, and can certify their "correctness and completeness". I'm still not certain the engine will run, but my gut tells me it will.---Besides, Roland is running out of things to build!!!! First we start out with a general arrangement----and if you save these plans, please show your appreciation with a karma point.---And if you see that I have totally screwed up somewhere tell me so I can correct it please.---Brian









View attachment ASSY-BRIAN RADIAL NEW TRY.PDF


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## Brian Rupnow (Oct 10, 2009)

First of all, lets build a base to mount things to--






View attachment BASE FOR RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 10, 2009)

Then a vertical stand to hold up the main body---





View attachment VERTICAL STAND FOR RADIAL ENGINE.PDF


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## zeeprogrammer (Oct 10, 2009)

Nice Brian.
I went back a few posts and found some nice gems for my learning.
In particular the part about rake for a brass cutter. I understand more now.


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## Brian Rupnow (Oct 10, 2009)

Then an updated edition of the big starfish main support body--





View attachment MAIN SUPPORT FRAME-RADIAL-NEW TRY.PDF


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## Brian Rupnow (Oct 10, 2009)

And Oh yeah--You're going to need a gasket between the vertical support and the main body--





View attachment GASKET.PDF


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## Brian Rupnow (Oct 10, 2009)

Every engine needs a main bearing--





View attachment BEARING FOR RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 10, 2009)

And a crankshaft (even if I did call it a "crank Throw")--





View attachment CRANK THROW BRIAN RADIAL NEW TRY.PDF


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## Brian Rupnow (Oct 10, 2009)

And a hub for all those crazy connecting rods to attach to (the master rod, which is the same as all the other rods actually gets soldered to this hub)





View attachment CONROD HUB-BRIAN RADIAL NEW TRY.PDF


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## Brian Rupnow (Oct 10, 2009)

And speaking of connecting rods---





View attachment CON ROD FOR RADIAL ENGINE-NEW TRY.PDF


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## Brian Rupnow (Oct 10, 2009)

And we'll need some pistons to go on the end of those con rods





View attachment PISTON FOR BRIANS RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 10, 2009)

A cylinder (or five)





View attachment CYLINDER.PDF


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## Brian Rupnow (Oct 10, 2009)

Those silly pivot pins that get soldered to the cyinders---





View attachment CYLINDER PIN-RADIAL STEAM ENGINE.PDF


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## Brian Rupnow (Oct 10, 2009)

And if any of you are wondering why many of the drawings say "New Try" on them---Its because my first try at this design was a version with the connecting rods stacked and the cylinders offset. I didn't want to delete the first part designs I had made, so I "saved as copy" and renamed the parts as "New Try" to avoid "software confusion" issues.


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## Cliff (Oct 10, 2009)

Hey Brian your engine is looking fantastic and the prints are top notch as usual but the drawing on post #82 doesn't have a way down load it. Cliff


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## ozzie46 (Oct 10, 2009)

Also some are .jpg and some are .pdf


  Thanks for for posting them. I have a folder just for your stuff.  :big: :big:

 Ron


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## black85vette (Oct 11, 2009)

Dang! The first post for this was just on the 4th. You have got more done this week than I ever hope to learn how to do. Just one question: do you ever sleep??


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## Brian Rupnow (Oct 11, 2009)

Cliff  said:
			
		

> Hey Brian your engine is looking fantastic and the prints are top notch as usual but the drawing on post #82 doesn't have a way down load it. Cliff


Cliff---I fixed that.


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## lathe nut (Oct 11, 2009)

Brain, you make it seem so simple to draw and build, some day, I say a well spring of wisdom, thanks, I will have to get a lot better to try that one but copy, paste and save to file for now, thanks again, Lathe Nut


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## Brian Rupnow (Oct 11, 2009)

These small engines alwys work a bit better when you have something to connect the airline to--





View attachment AIR INLET-RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 11, 2009)

Here are some sub-assemblies that will help a great deal





View attachment SUB ASSY OF CYLINDER AND CYLINDER PIN.PDF


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## Brian Rupnow (Oct 11, 2009)

And another sub-assembly--






View attachment SUB ASSY OF MASTER ROD AND HUB.PDF


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## Brian Rupnow (Oct 11, 2009)

And last but not least---





View attachment SUB ASSY OF PISTON AND CON-ROD FOR RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 11, 2009)

I'm going to show you a sneaky trick I used for putting the round diameter on the end of the rectangular cylinder without using my 4 jaw chuck.--First I drilled a 1/8" diameter cross hole about 1/2" in from the end of a peice of 3/8" diameter brass rod and put it in the 3 jaw chuck.
Then I slid the cylinder down over the end of it and pushed a peice of 1/8" diameter cold rolled shaft thru the 1/8" reamed hole in the side of the cylinder and into the hole in the brass rod. (This is a "posed" picture------in reality, the round diameter is not turned yet at this stage.)
Then I wrapped a peice of masking tape around it to keep the steel pin from coming out.
Then I went ahead and machined the diameter on the outside of the cylinder.
I am thinking that the reason I had some chatter marks is primarily that I had the end of the 3/8" brass rod stuck out a bit too far from the chuck jaws.


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## Brian Rupnow (Oct 11, 2009)

Well, Thanksgiving is over for another year at my house. We have our celebration meal a day early to allow me a day to travel up to Bancroft and collect my ancient mother on Saturday and deliver her home on Monday. Massive amounts of turkey and apple pie were devoured, and 4 generations represented, from my 89 year old mom to my 2 year old granddaughter. Sure thing, nobody left the table hungry!!! I tried to sneak down into my little machine shop for an hour, but got caught and yelled at by my wife, so no machining accomplished today. I'm tired, I'm stuffed, and I'm happy.----and a Happy Thanksgiving to all my Canadian friends on the forum.-----Brian


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## cfellows (Oct 11, 2009)

Good tip on the cylinder turning, I'll have to remember that. 

Chuck


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## Krown Kustoms (Oct 11, 2009)

Nice trick, thanks&#9786;
-B-


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## chuck foster (Oct 11, 2009)

nice tip on the cylinder turning :idea: never would have thought of doing it that way.

chuck


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## Brian Rupnow (Oct 11, 2009)

Five little piggies, all in a row---Company all went home, wife and mother layed down for a snooze, and I sneaked away to my shop. Finished up the last of my 5 cylinders. I used Kvoms suggestion of using a parallel for a "deadstop" at the end of my vice jaws and it worked just fine. Thank you Kvom--It made multiple set-ups much quicker. I just love it when somebody shows me a neat new trick!!! We are closing in on this engine. All I have left to make are 5 pistons and 4 connecting rods---and a whack of silver soldering.


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## Krown Kustoms (Oct 11, 2009)

Eagerly waiting.
-B-


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## ozzie46 (Oct 11, 2009)

Happy Thanksgiving to you Brian.

Ron


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## Cliff (Oct 11, 2009)

Thanks for the fix on post #82. I want to wish you and your family a Happy Thanks giving. Cliff.


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## Brian Rupnow (Oct 12, 2009)

A plethora of pistons---4 laying beside the cylinders and one mounted on the master rod.


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## cfellows (Oct 12, 2009)

Won't be long now... Lookin' good!

Chuck


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## Brian Rupnow (Oct 13, 2009)

This morning I finished the connecting rods. My, but they're tiny little buggers!!! I even found the piston I lost in the swarf pile last night ??? ??? (I lost track of how many I had made, could only find 3, so I built another. Now I have a spare!!! Yahoo---I just had some REAL WORK come in. Gotta quit playing machinist and put my design engineers hat back on now. Progress will be slowing down a bit now.


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## Brian Rupnow (Oct 13, 2009)

This evening we have 5 "Cylinder pins". Not the greatest threading job in the world, but the threads will be good enough to hold a #5-40 hex nut in place. (And yes, I used a threading die.) Now I'm off to the garage to silver solder these pivot pins into the cylinders.---Wish me luck!!!!


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## Deanofid (Oct 13, 2009)

Looks like there may be a problem with that die, Brian. Maybe it's time for a new one.
Are these threads on a 1/8" diameter?

Not criticizing! It just appears that you may have had trouble with these.

Dean


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## Brian Rupnow (Oct 13, 2009)

Yes, they are on a 1/8" diameter. As I said, they are not the greatest threads, but they will be sufficient to hold a #5-40 nut in place. They have to be chased anyways after my silver soldering is finished, and they should clean uop some then.


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## Brian Rupnow (Oct 13, 2009)

Making it up as I go along---Take#2----I decided not to build a jig to solder the cylinder pins in place. Since silver solder will not stick to aluminum, I turned five 3/8" diameter aluminum plugs to insert into the cylinders, full length. Then I used one of my home made gasket punches to cut 5 peices of 1/32" thick paper gasket to 1/8" diameter and dropped the circle of gasket material into the 1/8" hole in the brass cylinders. Then I set up one of my old vices and after inserting the cylinder pins I closed the vice on them, one at a time and silver soldered them. The vice is not tight--its just snug enough to keep the pins from jumping out of their holes when the flux begins to melt. The resulting steam as the water in the flux boils away will lift the pins out of the holes if they are not restrained as shown. The soldering was succesfull, and now the cylinders are cooling on the end of my desk. If I have lived right, I will be able to get the aluminum plugs out after things cool down.


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## lathe nut (Oct 13, 2009)

Brain, it would be best to wait till you are done to down load the drawing and thanks for posting the pictures of the parts and how they were made on the lathe or the mill for us who are not as sharp, I am ready to see it run, thanks again for sharing, Lathe Nut


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## zeeprogrammer (Oct 13, 2009)

Brian Rupnow  said:
			
		

> If I have lived right, I will be able to get the aluminum plugs out after things cool down.



Had I said that...it would be a certainty the plugs are there forever. Forever!

Enjoying the thread Brian. Thanks.


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## Brian Rupnow (Oct 14, 2009)

Well, I must have lived partly right!!! Three of the cylinder plugs came out with no trouble. Two of the plugs were stuck so bad that the ends twisted off the plugs. This turned into a serious mill and ream proposition, but they did come out. I will do the rest of the clean-up on the cylinders after my REAL WORKDAY is ended.


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## Brian Rupnow (Oct 14, 2009)

The cylinders are all finished, with the 1/8" diameter pivot pins silver soldered into place. Actually, they turned out very well. No matter how carefull I am with silver solder, I always manage to get some where I don't want it.--In this case, it migrated up the shank of the pivot pin on every cylinder, so I put my precision chuck into my 3 jaw on the lathe, held the cylinder assembly in it, and used my cut-off tool to machine the silver solder off the pin. (It has to be no more than 1/8" diameter or it won't fit into the holes in the main body.) I ran down to Canadian Tire after work today,hoping to get some #5-40 hex nuts, but wouldn't you know it, they had every size BUT the size I needed. I will go over to Brafasco tomorrow and buy some nuts, compression springs, and a 1/4" diameter shoulder bolt x 1/4" long to hold the connecting rod hub to the crankshaft. My Photobucket account is filled up right now, so I won't be able to post a picture untill tomorrow. It takes Photobucket 24 hours to verify that I am who I am so they can sell me Photobucket professional.


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## chuck foster (Oct 14, 2009)

ah yes brian.............but are you really you 

chuck


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## Brian Rupnow (Oct 14, 2009)

aermotor8  said:
			
		

> ah yes brian.............but are you really you
> 
> chuck


After 4 months of recession driven idleness, I'm really not sure if I'm me or not. I finally got a small contract this week, and if I get paid for it in a couple of weeks and not someone else, then I may be more sure I'm myself!!! ;D ;D ;D


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## Brian Rupnow (Oct 15, 2009)

THE ENGINE LIVES!!! And its an absolutely awesome runner. Now if I can get my photobucket straightened out,I will post a video.


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## black85vette (Oct 15, 2009)

th_wav  woohoo1

Way to go Brian. Can't wait to see it.


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## Krown Kustoms (Oct 15, 2009)

Glad to hear that it runs.
I was looking back and saw that all of your pics have been replaced with a photobucket logo.
They mean business when you fill them up.
I wont stray too far to see this one run.
Congrats on another "done one" 
-B-


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## kvom (Oct 15, 2009)

Personally I dislike photobucket and all the popup ads. Take a look at pbase.com - no ads, and pretty cheap.


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## Brian Rupnow (Oct 15, 2009)

Well guys, here it is!!! Its a great runner, and I have absolutely no complaints. It is built exactly as per the drawings (except I didn't chamfer the base yet.) I wish all of my builds, (and yours) would go as quickly and easily as this one.---Brian


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## ozzie46 (Oct 15, 2009)

Brian, it seems you can think up, design and build a project in about the same time it takes me to think about what I want to build next. :big: :big: :big:

Great job.  :bow: :bow: :bow:

 Ron


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## chuck foster (Oct 15, 2009)

* :bow: :bow: BRIAN DOES IT AGAIN!!! :bow: :bow:*

way to go, great looking engine and runs real fine

chuck


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## zeeprogrammer (Oct 15, 2009)

Fantastic Brian. Congratulations.
This was interesting and got me thinking about radials.
Thanks for the thread!. Great.


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## Brian Rupnow (Oct 15, 2009)

And here are a few still shots of the finished engine.


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## putputman (Oct 15, 2009)

WOW Brian. Runs great!!! :bow: :bow: :bow: 
 ???I have been following the build, but for some reason, I didn't realize how small it is. ???
I have used your designs and ideas in the past and this is definitely added to the list.
I hope I am around when you finally retire and just design toy for us guys.


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## Brian Rupnow (Oct 15, 2009)

putputman  said:
			
		

> WOW Brian. Runs great!!! :bow: :bow: :bow:
> ???I have been following the build, but for some reason, I didn't realize how small it is. ???
> I have used your designs and ideas in the past and this is definitely added to the list.
> I hope I am around when you finally retire and just design toy for us guys.



It is a little devil, isn't it---but there is a reason I made it that small.. The very first engine I ever built was a little Elmer Verburg wobbler, and it ran so well that I used the same cylinder design as the one on Elmers engine. Its a 3/8" bore and 1/2" stroke. When I started to design the main frame, I seen how small it was going to be, but figured that there are a lot of fellows out there with little Taig and Sherline hobby lathes/mills that are very limited as to how large of peices they can machine. I think this will be a very popular engine, so I kept it small on purpose.----Brian


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## Krown Kustoms (Oct 15, 2009)

It runs great
Thanks for the extensive build log, I think most anyone could build this one with your documented build.
-B-
I am gathering up materials for this one.


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## Brian Rupnow (Oct 16, 2009)

Whoops!!!---Forgot the flywheel drawing. I decided to go with a plain flywheel, as its greater weight really helps smooth out the opration of this little engine.





View attachment FLYWHEEL FOR RADIAL ENGINE.PDF


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## Brian Rupnow (Oct 16, 2009)

And you will also want this spring information





View attachment SPRING FOR RADIAL ENGINE.PDF


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## Krown Kustoms (Oct 16, 2009)

Thanks Brian, I havent gotten for enough to see that they were missing.
-B-


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## Brian Rupnow (Oct 16, 2009)

This should get you a complete download of .pdf files of all the engineering drawings..
<a href="http://www.mediafire.com/?uzhvza0ywmn">http://www.mediafire.com/?uzhvza0ywmn</a>


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## Krown Kustoms (Oct 16, 2009)

Thanks
that works out better
-B-


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## NickG (Oct 16, 2009)

Brian, 

That is a great design and it runs superbly. Having seen the video I will have to study your porting arrangement in more detail, didn't realise it was all hidden!

Thanks for sharing.

Nick


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## kvom (Oct 16, 2009)

Latest challenge" build one faster than Brian did!  ;D


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## Krown Kustoms (Oct 16, 2009)

Brian, just to give you a heads up.
you have the dim for the spring at .2 on the drawing.

Its no big deal, everyone knows .2 is a bit big for spring wire, so natrually to adjust to .02
-B-


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## eskimobob (Oct 16, 2009)

Glad to see it run - superb job - very encouraging when a project moves this fast - gives me hope that I might eventually finish something :big:

Many thanks Brian :bow:


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## Brian Rupnow (Oct 16, 2009)

Krown Kustoms  said:
			
		

> Brian, just to give you a heads up.
> you have the dim for the spring at .2 on the drawing.
> 
> Its no big deal, everyone knows .2 is a bit big for spring wire, so natrually to adjust to .02
> -B-


Thanks--I fixed it.---Brian


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## Cedge (Oct 16, 2009)

Well done Brian. I wondered if the five cylinder might somehow seem less "alive" than the 6 cylinder version but both definitely have that same hyperactive organic effect. Congrats on coming up with a simplified design for what has been a classic eye stopping engine, for a long time.

Steve


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## lathe nut (Oct 16, 2009)

Brian, thanks again you are so good to use for sharing your knowledge, got projects for some time to come, it looks alive instead of running, that is cute, my question is what is next, I know that you have to have something in mind, let us hear it now, thanks again, your great, Lathe Nut


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## Cliff (Oct 17, 2009)

Thanks for a awesome post it is all top notch engine, post, and prints all top of the line. Cliff.


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## Brian Rupnow (Oct 18, 2009)

I registered with "Youtube" this evening and posted the link on there.
[ame]http://www.youtube.com/watch?v=FuB7YPVqKC4&layer_token=2cf62e5aa9393472[/ame]


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## Brian Rupnow (Oct 22, 2009)

I am doing up an article based on this thread for a magazine publication. Consequently, I took some time and put the drawing of the star shaped main body on 3 seperate detail sheets, so it would be a bit easier to read. The .jpg only shows the first sheet, but the .pdf file has all 3 sheets on it, if you click on the link.---Brian






View attachment MAIN SUPPORT FRAME DETAILS-BRIANS RADIAL ENGINE.PDF


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## Krown Kustoms (Oct 22, 2009)

Thanks, that helps a lot.
There is a lot going on in the original drawing.
Im not a good print reader... uhh ... let me start over- I dont read prints very well, good ones or bad ones.
(I guess thats why I build my own designs, now that I think of it)
-B-


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## Brian Rupnow (Oct 23, 2009)

I found a fellow in Barrie who has a business sharpening end mills for all the local machine shops. He sharpened all of my end mills, and made me up a ball nosed cutter and a 45 degree chamfer cutter. He has a big CNC machine that can do sharpening and custom grinding amost instantly. this is a picture of the chamfer cutter doing its thing on the base for my radial engine. It works really slick, but I found it does leave machining marks regardless of what speed I run it at.---A bit of light sandpaper fixes that very quickly. So--the base ends up a lot classier with a 45 degree chamfer all around the edges.


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## Deanofid (Oct 24, 2009)

Looking good all polished up, Brian!
I don't know which way you ran the bevel cutter into the work, but if you make the last pass about .001" and climb mill it at high spindle speed, it may clean up the cut a bit. You've got this piece all cleaned up now, but next time you use that cutter you might give it a try.

Dean


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## chuck foster (Oct 24, 2009)

brian : if you make the base out of aluminum you could use carbide router bits they will give you a nice finish and they are not to expensive. they come in a multitude of different shapes and sizes and profiles. 

just a thought 

chuck


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## Brian Rupnow (Nov 9, 2009)

Is anybody out there building this engine? I know Roland started to, then ran into a glitch and hasn't posted since. I'd be really interested in knowing.---Brian


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## Metal Butcher (Nov 9, 2009)

Hi Brian. First chance I get I would like to look over the plans. Seems like a big project for a beginner like me... but you never know.

I've been away for a bit and didn't follow your build. 

MB


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## lathe nut (Nov 9, 2009)

Brian I am scraping around for some material and trying to build up enough nerve to try it, looks like a lot for me but guess If I build one piece at a time I can get it done, guess it is like life, its a sinsch if you take it inch by inch, I got the drawing and copy and past everything that you posted, bringing a copy to my Machinist friend retired 30 years in the trade and he good but we are some distance apart, I know he can do it with easy, thanks again, Lathe Nut


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## Krown Kustoms (Nov 11, 2009)

Brian, I am still working on the radial.
I had a set back when I cut the anulus on the wrong side.
I built the upright and base but I havent had time to do much more, I will post pics on the build log when I get time.
-B-


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## Brian Rupnow (Nov 11, 2009)

Krown Kustoms  said:
			
		

> Brian, I am still working on the radial.
> I had a set back when I cut the anulus on the wrong side.
> I built the upright and base but I havent had time to do much more, I will post pics on the build log when I get time.
> -B-



I think you could easily save that piece by drilling all 10 of the 1/16" holes completely though the star, then seal up the ones opposite the annulus side with some epoxy.


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## kvom (Nov 11, 2009)

Brian,

WRT the plans for the spokes, I personally would prefer to see dimensions for the holes given as bolt circle radius.  I would want to drill them, as well as cut the profile, with the material mounted on my rotab. Given the position on each spoke, a rotation of 72 degrees positions the next.

Just my .02


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## Cedge (Nov 11, 2009)

Metal butcher...
Never look at a build as an entire project. You will only be making one part at any given time. Then you move to another part and so on. Brian already did the heavy lifting by providing you a road map. You only need follow it. Soon you have a whole bunch of parts and you can then begin to think in terms of the whole project as you begin assembly. 

Simply concentrate on the part you are making and the overall complexity never becomes much of a factor. You'll quickly overcome that feeling of being overwhelmed by "so many parts". The recent Victorian engine project would have been totally beyond me had I looked at it any other way. Go for it and you'll see what I mean.

Steve


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## Krown Kustoms (Nov 14, 2009)

Thanks Brian, I tried that but then I had a bunch of pathced holes that looked funny.

I am working on another now and it looks a lot better (CNC).

Metal Butcher - I agree 100% with Cedge - Any project will have a bunch of parts, you have to finish each one first before you complete. Look at one part at a time.

I have built a few motorcycles from scratch and to look at the finished bike it looks hard to do. One part at a time adds up to an easy build, the hard part is getting everything to fit right and look good.

-B-


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## lornetw (Mar 9, 2014)

Hello Mr. Rupnow. I don't know if this is an active thread, but here goes!

I am a teacher who teaches CNC machining  (manual programming, CNC machining and MasterCAM) in a trade school in  Montreal, Canada (school name : Cente Anjou, see : www.cspi.qc.ca/centre-anjou/).  We have about 15 CNC machines (milling and lathes) and three of our new  machines have CNC rotary tables. We also have three CMM machines for  accurately inspecting all the parts.

I am looking for a real cool  project for my students and I would like to do your radial engine (AKA  Brian's Radial Engine). What I really like about your engine is that  there are no really small fragile parts and the engine parts would be  easy to machine on our CNC  machines. I would like to know if you would give me permission to use  your radial engine as a project for my students.

If so, I would like to ask you a couple of questions.

CONROD  HUB : After studying your drawings for quite a while, I would like to  know if I have understood the mechanism properly. If the master Conrod  is silver soldered to the Conrod Hub, that means that it never pivots  (just thinking to myself !). If I understand correctly, the other  Conrods are also fixed and do not pivot because they are fixed with  Loctite. Is this correct?  If this is correct, the only reason the  engine can rotate is because the Cylinders pivot and the Conrod Hub  probably rocks slightly back and forth for each revelation of the Crank  ?  Or is the the Loctite just to lock the small 1/8 inch rod that holds  the end of  the Conrod  pin in place ?

If so . . . .  I was  thinking of doing a modification. If the above paragraph  is correct, could I replace the Conrod Hub with a solid pentagon hub  (with no groove) and drill and tap 5-40 at the correct spot on each  face. The Conrods could then be simple threaded rods. Or am I missing  something ?

When I first looked at the plans I was *sure* that the other Conrods (other than the master one) *had* to pivot in the Conrod Hub or they would break.

CYLINDER  : I always buy Machinist's Workshop and Home Shop Machinist (that's how  I found your engine !). So, after reading your explanation on page 26  of the Jan/Feb issue of Home Shop Machinist, I had a question regarding  the path of the airflow in the engine. By the way, I took the liberty of  changing the Air Inlet to an NPT pneumatic fitting (so my students can  practice tapping NPT). I can follow the airflow path, starting from the  side of the Vertical Stand, up into the circular annulus, into the  (5 arm) Main Support Frame (via its own circular annulus), up the  length of the arm and out the hole on the face of the arm. After that I  presume it is the rocking action of the Cylinder that permits the air to  enter into the top of the cylinder, pushes the Piston down and when the  cycle is finished, the cylinder rocks (pivots) the other way (as the  piston rises in the cylinder), letting the air exit by the other hole  that goes completely through the arm. Is this correct ?

NOTE : I  am using MasterCAMx7 to do all my drawings (production drawings, solids,  etc) and to generate the G-codes to machine the parts. If you give me  permission to do this project, I will keep you posted on my progress. I  am attaching a screen grab of my progress so far.

Other modifications :
I  will also be adding a small SHCS, screwed into the back of the flywheel  so the student can rotate the engine manually and thus show off the  interesting movement of the  mechanism.


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## Brian Rupnow (Mar 9, 2014)

Wow--You sure reached back a long ways in time to find this thread. You have my blessing to use the plans in any way you want.  Its been so long since I built it that I had to get it down off the shelf and have a look. Although the master rod is fixed in relationship to the center hub, all of the other rods do indeed pivot at the central hub. They have to, or it wouldn't work. Forget about a pentagon hub and the threaded con rods. If I mention Loctite in that area, its a small dab of Loctite to hold the pivot pins in place in the central hub, otherwise they would work their way out. You have the airflow mostly right. The annulus is used to feed pressurized air to the cylinder to make the piston go from top dead center to bottom dead center. When the movement of the central hub forces the piston from bottom dead center to top dead center, the cylinder rocks the other way so that any air trapped ahead of the piston can escape.---Brian


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## lornetw (Mar 10, 2014)

Hi, Mr. Rupnow.

Many thanks for giving me your permission to use your engine. Also, thank you for the explanation of how it works, this will help me in doing all the parts and the fixtures. I will keep you updated on how we are getting along making all the parts.

Regards,

Lorne Wilkins


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