# Six Shooter Elbow Engine



## Ken I (Dec 5, 2011)

Spurred on by the thread "elbow engine leaks too much" I have been posting to try and get some suggestions for a less leaky elbow engine design.

Captain Jerry has provided some valuable input.

Herewith the design so far :-

Using internal porting via the shaft with a cover plate bolted to the base of the cylinders I'm trying to eliminate the leakage from the exposure to the full piston diameter / clearance.

Any leaks will be confined to the bushing / shaft clearance instead.







Since all the thrust will be backwards there is a thrust ball bearing - unconstained diametrically to the cylinder to prevent binding due to concentricity issues.
I have incorporated a bushing as per Captain Jerry's suggestion and a radial ball bearing at the top, the cylinder then turns on 7mm of 10 diameter shaft (3.5mm ether side of the porting for sealing), the radial bearing at the top and the thrust bearing at the bottom.

I've added a hardened thrust washer to the elbow for the piston thrust face, this will either be a push fit or locktite to the elbows.

I am considering making a turning fixture for the elbows - they would still be bent from rod - but the 4mm piston running diameter would be machined in the fixture after bending to get it dead square.

I have only a rudimentary flywheel sketched in at the moment - I'm hoping to build a motor that will run without it as I want to add some "bling" features to the cylinders to make them look like a revolver cylinder.

Hence the name "Six Shooter" 


Ken


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## Captain Jerry (Dec 5, 2011)

Excellent design, Ken. I think you have all of the bases covered. The stiffener bracket is great idea. One common statement from other elbow builders seems to be the fiddly effort to get the two cylinders aligned. The bracket will either make this easier or harder. I am pulling for easier.

I can't wait to see the turning fixture that you come up with. If it works out, you will have resolved the squareness issue nicely. I hate bending stuff!

Jerry


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## Noitoen (Dec 5, 2011)

I imagine that the bent shafts could be replaced by flexible shaft or not??


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## Ken I (Dec 5, 2011)

Noitoen, No - the elbows "push" the cylinders around - so flexible elbows won't work.


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## Noitoen (Dec 5, 2011)

But flexible shaft like speedometer cable isn't "springy" and could do the pushing like solid shaft and would solve the perfect 90º "squareness" need.


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## Ken I (Dec 5, 2011)

Noitoen, I see what you are thinking - but the elbows do not transmit torque (A'la Bowden - speedo cable) but are rigid - each piston pushes its opposite number in the other cylinder so a Bowden cable would flex in this mode.
I do see your point however, I'll play with the idea - but I don't think it will work.

A bit of lateral thinking won't hurt though.

Thanks.

Ken


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## mklotz (Dec 5, 2011)

I'm inclined to agree with Noitoen. In fact, I think I remember seeing somewhere an elbow engine where the pistons were joined by a lap joint transected by a pin (think hinge joint). Such a joint allows the pistons to angle toward or away from each other, thus self-correcting *minor* alignments, but does not allow one piston to rotate relative to the other.

I can't think of any reason why it wouldn't work - although that may just demonstrate my poor visualization skills.


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## Blogwitch (Dec 5, 2011)

One place you might have a problem with Ken are the central holding bolts.

With just 3 pistons they are difficult to get to, goodness knows how bad they will be to reach when you have 6.

BTW, Stew did the 'revolver' shaping on his elbow engine.


John


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## Captain Jerry (Dec 5, 2011)

I have given some thought to speedo type cable in the past, sheath only, no core, and the idea is good but the material is wrong. It takes a fair amount of force to bend the cable 90 degrees in a short distance and that can't be good for piston/bore friction. Maybe something lighter, like a small tension spring. A half lap joint could work, but a knife/fork joint would be better. After thinking about these solutions for too long, I realize the time could be better spent thinking about ways to be sure that all of the elbows are square and that the two shafts are co-planar.  One way to solve the co-planar problem would be to make one additional elbow that fits a socket in the end of each shaft. With the valve moved to the shaft, there is no force driving the cylinder off of the shaft so there is no reason to think that it wouldn't work but Ken's bracket does the same thing and is much more rigid.

Jerry


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## Ken I (Dec 6, 2011)

Marv, Captain, the knife / fork joint makes a lot of sense but doesn't sit well with my stiffener or the asthetics - but clearly helps with alignment issues. I'll keep that in the "just in case" mental folder for now.

Noitoen, I had already been considering a "springy" elbow - but I was thinking along the lines of making it from spring wire - the thinnest that might work so that alignment issues are taken up by "flex" in the elbow. I was thinking along the lines of 2mm diameter wire - but this doesn't sit well with the asthetics.

However it gives food for thought - how about I retain the internal piston shaft portion of the elbow - drill it 2mm (see attatchment) fit the piano wire elbow and silver solder it at the circlip end ? it should be far enough away not to heat damage the temper of the bend ?

John, yup the bolts are a problem in that it uses two in close proximity - one goes through the seat and the other through the seat and the base - this makes the assembly arkward but not impossible - I think (hope) that I have thought this through - I have the assembly planned out in my head.

I'm also thinking that if I use "O" rings on the non-rotating pistons, I can get away with some clearance which will help the alignment problem which is likely to be severe with a close running fit piston - hopefully not wishful thinking.

I can always abandon three of the six cylinders if it all gets too pear shaped (put fake "bullets" into the redundant holes).

So I'm already thinking of whatever plan "B" might be required.

I vaguely remember the term six-shooter was used before so kudos to Stew. I did a search but came up bupkis.

I have also designed a reversing throttle valve to go with this as part of either the base or vertical (it doesn't really affect the design at this stage).

Thanks for the input - it is all appreciated.

Regards,
        Ken


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## Blogwitch (Dec 6, 2011)

Ken,

The pistons don't just go in and out, they rotate slightly as well.

When you have run the engine a while, you will see a 'herringbone' pattern on the piston sides.

In all honesty, I don't think you will be able to seal it up completely. I got my running gap under the cylinders to about 0.002", any tighter and it just locked up solid, purely because you can't get rid of all flex in the central bolts, even with shoulders on the bottom.
I spent many hours playing about with the gap and different central bolts, all to no avail, it still managed to throw a stripe of oil onto the back of a chaps jacket when I was displaying at a show, I didn't tell him BTW.


John


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## Ken I (Dec 6, 2011)

John, I bet his wife wanted to know - oops.

I'm hoping the 10mm diameter pistons will rotate on the 4mm diameter elbow ends - so they will remain rotationally static with respect to the cylinders - the "O" rings will then not rotate in the bore (high friction) and the piston is then a straight in and out function.

They will tend to rotate irregularly which will hopefully eliminate the herringbone pattern associated with the regular locus of motion within the bores.

With this design the cylinders can float and it won't affect the leakage at all.

The only leakage will come from the shaft / distributor porting (bush to shaft clearance) and the piston to elbow clearance which should be low given the small clearance and length.
Captain Jerry has also suggested "O" ring seals on the axle this would eliminnate all leaks bar the inlet to exhaust bypass past the anulus interrupt - and that goes out the exhaust - not your shirt.

I don't like using "O" rings for rotary seals - on anything but really slow speeds they tend to burn / fail because there is no lubrication mechanism.

In writing this I just remembered I have some suitably sized seals - so maybe I'll incorporate something - the worst that can happen is I'll have to junk them.

All this is of course hopefull / theoretical - the proof of the pudding however.......

Regards,
      Ken


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## Noitoen (Dec 6, 2011)

Bogstandard  said:
			
		

> Ken,
> 
> The pistons don't just go in and out, they rotate slightly as well.



They don't rotate slightly, they do 360º. They function as a crank to rotate the barrel.


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## Ken I (Dec 6, 2011)

Noitoen - correct the pistons rotate in the cylinder 1 rev per rev - where the elbow and piston(s) are solid units.
In my design they will rotate on the elbows - remaining stationary from the viewpoint of the cylinder.

I'm still waiting for someone to tell me why that won't work ?

Ken


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## Foozer (Dec 6, 2011)

Ken I  said:
			
		

> Noitoen - correct the pistons rotate in the cylinder 1 rev per rev - where the elbow and piston(s) are solid units.
> In my design they will rotate on the elbows - remaining stationary from the viewpoint of the cylinder.
> 
> Ken



Isn't it the barrel that rotates around the piston in the solid piston/elbow design?

Other than an additional point of friction and fiddly machine work, the rotating piston scheme should work. 

Robert


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## jor2daje (Dec 6, 2011)

Just throwing an idea out, couldn't you mill perfectly 90* elbows out of flat stock, then attach to a face plate to turn the piston diameters. Then with a radius tool, rotary table and some creative fixturing mill it to look like a rod? Im still quite an amateur so no idea how practical this would be. Ill add some pictures to explain if that wasnt clear.

edit: heres the pic, though im sure you get it


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## Ken I (Dec 6, 2011)

Foozer - I'm talking relatively here - the cylinder rotates and the pistons go up / down / in / out but don't actually rotate relative to your viewpoint - but from the cylinder's viewpoint they rotate within each cylinder.

By having them rotate on a smaller diameter, I reduce friction losses. Also if I use an "O" ring to seal the piston - its relative motion to the cylinder is in and out only - rotation on "O" rings not a good idea (obviously if I don't seal the piston this additional bearing merely creates a new leakage path which would be worse).

The torsional friction on the elbow will cause the piston to turn slowly which will hopefully even out the wear patterns.

I was just adding seals to the design when my system decide to crap out on me and I've just lost about an hours work - dammit when its going well you forget to save - my own silly fault.

Jor2daje, that is one possible way I've also been considering - in fact I've even drawn some tooling - but I think I'm going to try the spring wire - its different and offers some simple possibilities and possible advantages.

Ken


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## Noitoen (Dec 6, 2011)

You could make the pistons out of PTFE and solve the sealing problem. :hDe:


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## Foozer (Dec 6, 2011)

Ken I  said:
			
		

> Foozer - I'm talking relatively here - the cylinder rotates and the pistons go up / down / in / out but don't actually rotate relative to your viewpoint - but from the cylinder's viewpoint they rotate within each cylinder.
> <snip>
> The torsional friction on the elbow will cause the piston to turn slowly which will hopefully even out the wear patterns.
> 
> ...



Guess it is from observational point. From the barrels center, then viewing the piston as the barrel does a 360. I will see the full 360 of the piston so it doesn't rotate. Semantics.

The wear pattern would probably polish/burnish itself out should one of these engines be left running more than a minute or two. Always figured that the start up wear pattern being even over the part meant a good fit 

Robert


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## Captain Jerry (Dec 6, 2011)

Ken

What are you planning to use for bore diameter?


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## Ken I (Dec 7, 2011)

Captain, its 10mm bore by 30mm stroke (the PCD).

Here's the design as I'm probably going to build it.

I have incorporated seals for the axle and "O" ring grooves for the pistons. I'll build it without the seals initially to get everything sorted out first - then we'll see if the engine can handle the friction of all those seals.

If it all works the only places it can leak is out the exhaust (anulus interrupt bypass) and up the 4mm diameter x 30mm long "bearing" portion of the elbow that the piston turns on - this should be very little and lube sealed.

The axle seal is not a pressure seal but should handle 100 psi easilly enough (I once in an act of wishfull thinking subjected one of these to 2000 psi - it failed after a couple of hours use - I expected it would turn inside out instantly).

I'm going to go with 2mm spring steel elbows silver soldered into the piston "axles" - I'll be making a jig to hold both axles in the correct position during soldering - so with a bit of luck they should come out spot on - the flex and torsion in the spring steel wire should be more than ample to drive the motor but light enough to accomodate any errors without undue side loading friction.

Noitoen - if that doesn't work I'll definately try PTFE pistons.


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## Ken I (Dec 29, 2011)

O.K. - After getting the self-propelled gearwheel out of the way, I can finally get stuck in to the elbow engine.

I have tried to design around some of the problems inherrant to the engine - leaks in particular as outlined above.

I machined the bores of the "6 Gun" barrels by spotting, drilling, boring and reaming on the RT.

I have learned not to trust drill and ream for accuracy and in such circumstances as will permit I prefer to bore before reaming - to get rid of runout errors.






Note the split adaptor bush in the boring head - the hole in this is deliberately at 1/2° skew so I don't need to worry about clearance or rubbing on the boring bar.

Note also I have mounted the cylinders on a sacrifical piece of 16mm MDF - I miked it up to be sure it was parralell and clocked after tightening to ensure it did not compress unevenly - it worked - having said that a piece of aluminium would have been a better idea - I needed something to drill through into.

I have a location pin setup for the RT but for really accurate work I prefer a dial gauge and a mallet to get it as true as possible. I'm just a caveman at heart.

I machined both cylinders with the same set up to get them the same.

After machining I was able to mount both barrels on 3 x 10mm groundbar rods an can pass a piece down and through the other barrels (I don't have 6 pieces to hand) - this demonstrates the bores and pcd's all line up and are paralell - a great result.

I would like to tell you this is true for all 6 positions - which it should be if spot on - however one positon is great, 4 are slightly tight and one is very tight - I only need one and will mark these for the matching cylinders on assembly.

More in due course.

Ken


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## rustyknife (Dec 30, 2011)

If I may offer my piston bending/making advice. Mine were made from drill rod.

As you realize, its tough because the piston has to be square in two planes. When I did mine, I decided to make a jig to bend them. I put the set screws above centerline to clamp that one side against the inside and toward the bottom of its groove, then I heated with a torch and bent it against the other edge.






I did this for two pistons and they turned out dang near perfect. Just a couple thousanths off. very easy to fix with a test indicator, a dead blow and a milling vise.

The third piston broke during bending. Soooooo I clamped the other piece to the opposite side and oxy-acetylene welded the joint......This piston was PERFECT. Not even .001 off, in either plane

If I were to do it all over again, I would make that jig again with clamping segments on each side, and make each piston in two pieces, welded together...As long as your mills x and y are on par, it has to end up with a perfect square piston.

Regards,
Eric


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## Ken I (Dec 31, 2011)

Rustyknife - I followed your thread at the time - that will be my plan "B". Thanks.

Next I made a jig to mount the cylinders on for a bunch of second op work.






A pair of tube dowels for location - the 14° angle is for a later operation for the timing holes - not really necessary but this chunk of aluminium already had a 15° angle on it.

This might seem like a lot of trouble but I intend to get a lot of mileage out of it and it helps with headroom on the minimill.

Drilled & tapped all the base holes in one set-up simply by moving from cylinder bore to bore.






Then I fitted the end cap and spotted one hole - secured with a c/sunk cap and continued from there the same way.






Cylinder c/w bases.






Next step - bearing bushings, timing holes and "bling".

A question regarding the "bling" - the revolver location groove on a regular revolver is actually off-centre to the chambers - I have designed it on centre as I think this might otherwise look odd - but then some purists will be certain to tell me I should have placed it off-centre.

What's your opinion ? on-centre or off-centre ?

May I wish everyone at HMEM a happy, prosperous & accurate new year.

Ken


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## rustyknife (Dec 31, 2011)

The purists who might complain, have never built an elbow engine. You should make it exactly as you would want it.

Its looking great so far.

I can't wait to see the air ports drilled


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## Ken I (Jan 1, 2012)

Next job push in the bearing / timing bushes and drill the timing holes.

More tooling :-





A drilling bush and a specially modified cap screw.

The screw also doubled to press in the bronze bush :-






There is no way to start the drill at 14° without having it wander all over the place so a mild steel bush with a matching 14° slope allows the drill to start square - for the first drilling the bush is clamped in place (in order to drill the bush) - thereafter you only need to hold it with your thumb just to get the drill started - once the hole has started there is no need for the bush which just gets in the way of swarf clearance.






Bottom right shows the cylinder with all the timing holes drilled through.

Now for the bling - but I have to first make a Woodruff style cutter - I also discovered why the location notch is off-centre on a real six shooter - it gives you a bit more "meat" - my original design broke through into the cylinder - fortunately I spotted the error before wrecking what I have done thus far.

Ken


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## Ken I (Jan 2, 2012)

All the following effort is for "Bling" non-functional - appearance only.

The milling fixture very useful for all this.




Milling the flutes with a 12 dia. ballnose cutter.

Then I had to make a cutter out of drill rod to mill the detent grooves.






The fixture should really have been square for this (it's at 14°) but that would have been more work and this is only for appearances - still it does give the repeatability.

The finished cylinders :-






These were a lot of work - I've yet to decide what to make next - probably the axle or base mounting.

Ken


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## Ken I (Jan 4, 2012)

I found I needed to assemble the seals and bearings into the cylinder to determine the final shaft lengths (can't trust my own drawings) - this turned into a lot of fiddly work as the bores were all too tight and had to be meticulously mounted on the 4 jaw - a PITB when you have to spend a day to get back to were you thought you were yesterday. Ah Well.






Now for the distributor shafts and the porting in the bases.

Ken


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## Ken I (Jan 6, 2012)

Got the ported bases done without breaking any drills at the intersecting holes. I got lucky when a drill became swarf bound (stupid) and jammed but fortunately spun in the chuck rather than snapping off. Lesson - clear swarf more frequently.

Not a lot of wiggle room as the holes have as little as 0.5mm clearance to surfaces or ajacent holes.






I did the up side first, then stood the RT on end and rotated 90° to drill the cross holes - put the RT back flat and turned over the part using the cross holes to realign. More time spent setting up the RT and alignment than actual machining time.

Next the distributor axles and main plates.

I see a lot of people looking in but very few comments ?

Ken


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## vcutajar (Jan 6, 2012)

Hi Ken

I have been following your build from the start. I am just a novice in model engine building so I enjoy to see how people do things. Keep it up.

Vince


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## Captain Jerry (Jan 6, 2012)

Ken

I have been watching from the start. Your plan is clear and your goal is noble. The hopes and fears of future elbow benders are on your shoulder. I have a piece of cast iron bar set aside for pistons and bushings waiting for the completion of this project before I start mine. Most modifications of this design have just been cosmetic but your design is revolutionary.

After every engine build that I have completed, I have a list of things that I should have done differently or wish I had done so I'm waiting for your recap.

Jerry


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## Blogwitch (Jan 6, 2012)

> I see a lot of people looking in but very few comments ?



Even though I got my elbow engine out of my system a fair while ago, in fact it was the first elbow build to be shown on here, I am still avidly following your build, even though not commenting much.

BTW, no jigging for mine, I bent my pistons by holding each end in a bit of pipe and holding the waisted bit in the flame and just bent it while still being heated. I had no troubles with them cracking or twisting, I just had to square them up to perfection when things were almost ready to go. It still runs to perfection today even though it has many display hours on it.

John


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## Ken I (Jan 6, 2012)

Thanks guys - as the comedians say - I know you're out there - I can hear you breathing.

When there is no response it makes you wonder if you are just boring the ears off everyone and should desist.

Just finished deep drilling 4mm dia x 123.5 deep (gallery holes in the frame plates) with a jobber drill silver soldered onto a shank, I'll post on it tomorrowish when I've finished the bits.

Ken


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## dsquire (Jan 6, 2012)

Ken

Your right. There are a lot of us out here watching with open eyes, mesmerized by what you are doing and just not quite sure what to say but enjoying every minute of it. Keep up the great work Ken. 
 :bow: :bow:

Cheers 

Don 1647​


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## miner49r (Jan 6, 2012)

Yes, I'm still breathing. Or is it panting and drooling. I can't type because I have shorted out our keyboard.

The "cool factor" of this build is way over the top. Not to mention the percision of engineering and skill that is bringing this to a reality.


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## Ken I (Jan 7, 2012)

Next job should really be the distributor axles but instead I decided to do the main plates as the deep drilling has been bothering me. 4mm diameter by 123.5mm deep is "deep".

I don't have enough headroom on the minimill so the vice is out. I don't have a square either - eureka moment - my RT base makes a nice square - so I added another pair of M8 holes to the base end and used it to clamp the part vertically.





The DTI is my shepherd etc. etc. - don't take anything for granted - it wasn't square.

So much so I removed the tramming dowel and adjusted the head - in retrospect a little madness methinks - this hobby will do that to you - 20 divisions on a 2 micron DTI may look like a lot but is in fact only 0.0016" (0.04mm) runout down a 140mm length for a drilled hole ??? unneccesary. Still an'all errors have a habit of stacking up against you so precision never hurts but it can be unneccearilly time consuming.

I didn't have a long series 4mm drill so I made one by silver soldering on an extension piece. I used 4mm drill rod - something smaller would have been better. So I was fussy about clocking it up in the 4 jaw - first drilled the extension piece and then turned the shank of the drill to a push fit - pushed it on using the tailstock but leaving a small gap which I silver soldered - returned to the 4 jaw for a cleanup.

The long series drill :-






I've made long drills like this many times - don't worry about the absence of flutes - it makes little difference as a jobber length drill will become swarf bound long before you've used up the fluted length and you have to start peck drilling - in this case I went 1mm per "peck"

Started with conventional spot drill and drill prior to using the long series.

Still running out of headroom I had to remove my flourescent light and vertical stop and then finally the drill chuck had to go and I made a further adaptor bush for the drill to mount it into the bore of my flycutter - this time I locktited the drill into the bush so I can heat it off later - it did the job just fine.

Just to put this in perspective here's the tool up and down.






Next the through holes - I mounted the part on the RT simply because it make the logitudinal alignment a doddle.






When I drilled the cross holes at the end of the deep drilling, three of the four lined up spot on and the one had wandered by about 0.2mm - WTH its only an air gallery - but it shows that deep drilling can wander - generally related to a poor start.

Just a few more holes - then the distributor axles and stiffener for a trial assembly.

Ken


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## arnoldb (Jan 7, 2012)

Good progress there Ken  - I like your angle plate Thm:

Kind regards, Arnold


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## miner49r (Jan 7, 2012)

Using the base of the rotary table as an angle plate was very creative. I am finding that half the challenge in machining is figuring how to hold the work piece. Especially when a specific tool is not readily availible.

I needed to cut facets in the cylinder for a wobbler. I was about to give up on the idea when the answer hit me. Mount a V-block sideways in the vice, a close fitting rod in the bore... (long story/short) it looked crazy, but worked.

Keep it coming


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## Ken I (Jan 10, 2012)

Made a start on the the distributor axles but ended up wrecking my first part on this build.





The axle in the foreground is very precisely 2.00mm short due to an error in my drawings - creative use of expletives is somehow mollifying.

Wasn't a dead loss as I was able to use it as a comparative measure to get the next two correct - I also discovered I needed the lead-in in order to assemble through the seals without damaging them.

In spite of the seal friction the assemblies turn easilly enough and very smoothly - I can rotate them with an air gun.

Now I have to set them up on the RT to do the porting and mounting holes plus the interrupted annulus for the inlet and exhaust.

Ken


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## arnoldb (Jan 10, 2012)

Ken, blame the short part on the heat wave - it was the correct length initially, it just shrunk in the cooler afternoon temperatures 


> creative use of expletives is somehow mollifying


 ;D DAMHIKT, but a libation of Namibia's finest should add to the mollifying effect. Unfortunately that does preclude any further shop for the day...

Kind regards, Arnold


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## Ken I (Jan 10, 2012)

arnoldb  said:
			
		

> a libation of Namibia's finest should add to the mollifying effect.



Three in fact Arnold.

Just get back on the horse........

Finished the the distributor axles.






Top left - drilling the ports & M3 mounting holes.

Then stand the RT upright without removing the part to retain angular alignment - a PITB as you have two parts to do but definately the safest way.
Top right drilling the port cross hole.
Bottom left machining the annulus groove 120° either side.
Bottom right - plan ahead. I have done this before where after meticulously clocking up the work etc. you then find you can't gain access with the cutter - lesson learned.

The finished axle(s).






Trial assembly of the cylinders - its starting to look like an elbow engine.






So far so good now for the stiffener bracket.

For some reason I've been putting off the "production run" of 12 pistons, 12 elbow axles, 12 elbow shoulders and 6 elbow assemblies - likely to get monotonous.

I've got an ER collet chuck on order which will help - should arive Thursday so I'll probably do the pistons over the weekend.

Ken


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## smfr (Jan 10, 2012)

That is looking very awesome. :bow:


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## Ken I (Jan 13, 2012)

O.K. the silly season is behind me - back to work dealing with all the PITB paperwork associated with running your own company.

Got the stiffener done - I changed the design slightly to three parts the stiffener and two spacers - it makes it easier to assemble and the spacers are qualifying spacers (where all the errors come home to roost).






Made the reversing throttle parts...





The second op on the one part looked like being trouble but I glued it to a scrap piece of Aluminium with superglue (sanded the surface first or you are just going to be stuck to friable oxides).






I deliberately worked it hard fully expecting it to come off - it didn't - this stuff continues to amaze me. A quick heat with the propane torch and the part came away clean - didn't even require glue removal.

Then I made the jig (more tooling) for silver soldering the elbows...






Made it as a single part then ran a 0.8mm slitting saw into it to cut off the "caps".

The assembly thus far......






Nothing left to do but the piston and elbow assemblies.

My ER collet chuck arrived but missing the 4 & 10 collets - on back order - precisely the two I need for the job - isn't Murphy a sod.

Can't keep putting it off so I'm going to make one piston / elbow assembly and see how that all fits together - better to find the obvious mistake after making one rather than all six.

That's all for now.

Ken


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## Blogwitch (Jan 13, 2012)

Ken,

Your build of course, but if I could just make a suggestion.

Because of the mechanics of operation, having just one area even a couple of thou out can lock one of these engines up solid, no matter how well the machining has been done.

My suggestion would be to give yourself a bit of adjustment, say make the upright adjustable side to side by a few thou, just elongating the assembly bolt holes slightly should be enough.

Plus BTW, even though it might turn over easily by hand either way when assembled, once pressure is applied to the workings, it can change the whole setup. But I suppose you will find all this out when it comes to fine tuning time. 

It's looking very good indeed.


John


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## rustyknife (Jan 13, 2012)

Its looking gorgeous so far! You've inspired me to want to build a revolver now....those cylinders look terrific.

Regards,
Eric


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## Ken I (Jan 14, 2012)

Bogstandard  said:
			
		

> make the upright adjustable side to side by a few



John, thanks for the tip - I hadn't really considered that alignment plane - good point. 
It also raises a small problem - I designed it to be secured with counterbored caps - so I can fiddle with those - however due to a mistake I had to turn over the plate and there wasn't enough room for another counterbore - so I've gone to countersink - that's not going to give me any wiggle room - so If I have a problem there I'm going to have to remake the baseplate (I hope not) Plan "B" will be shallow head caps.

I'm hoping that the torsion and flex in the 2mm diameter elbow wire (its 105mm long from anchor to anchor = silver solder at the end of the elbow axles) will accomodate a slew of evils. I may also end up "playing" with the wire diameter - a change from 2 to 2.5 wire increaces its torsional moment by 144% (a power 4 function).



			
				Bogstandard  said:
			
		

> once pressure is applied to the workings, it can change the whole setup



I hadn't explicitly thought of that but it must have been niggling at my subconcious when I added the stiffener. The gap between the chamfers on the ends of the cylinders is 0.5mm (design size) - but I can flex this from zero to 1mm with moderate force - due to flex in the 10mm aluminium base and vertical - so clearly the reaction forces from pressure in the cylinders can do that - the stiffener should take care of that.
You could also use a more robust base and vertical but that might end up rather clunky and ultimately everything flexes under load.

Thanks for the heads up - forewarned is forearmed.

Any other experienced elbow builders care to comment ?

Ken


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## Foozer (Jan 14, 2012)

Far from an experienced elbow builder, however, when it was lined up to rotate by hand it would not under air, wiggled it around (base hole tad larger per Bogs wording) and she would run on air but not by hand.

The Ah Ha is after it ran awhile, whatever was binding worked itself out, spins by hand and under air now.

I'm betting a donut yours will run right from the gate.


Robert


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## Captain Jerry (Jan 14, 2012)

Keep going Ken. The proof is in the pudding. I still have mixed feelings about the flexy wire elbows. I think your center bracket will eliminate flex in the frame and make the flex unnecessary in the elbows. Waiting for the results.

Jerry


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## Ken I (Jan 15, 2012)

Captain - you may very well be right - but I'm going to continue (for now).

O.K. got one piston assembly completed - these are all the bits and tooling.






Modified one of those cheap and nasty (but nonethess handy) circlip plier combo's to handle the DIN1400-4 circlip.

I decided to make the elbow axles in two parts - a shaft & shoulder washer - rather than turned from solid.

The brass split bush is for holding the 4mm diameter silver steel in my 4 jaw which does not go down to 4 (well) and to avoid damaging the ground finish.

Turned the circlip groove using my el-cheapo PO / Stanley knife blade lash up. WTH it works.

The silver soldered end is drilled 0.2 oversize for 3mm to give some wicking space for the silver solder.






I opted to start with 2.5mm wire (2mm seemed too flimsy) and bent it on my bending fixture.






If you are interested in the bending fixture its in the downloads section and you can follow the thread here :-
http://www.homemodelenginemachinist.com/index.php?topic=16976.0

Next - judiciously solder the wire and the axles in the fixture - don't want to get solder all over the axle OD or into the circlip groove - so I sort of chased the heat and the solder along from the gash end of the wire into the throat of the axle.





Followed by a trim with the Dremmel cut off wheel and a bit of off-hand grinding on the bench grinder.






The piston assembly :-






Next I'm going to trial assemble this into the motor and see what happens.

I'm out of suitably sized Cast Iron and so is my supplier (a wasted trip on Friday - should know better and phone first) - will start looking for some tomorrow - but it's likely to take me the best part of next week to get all six piston assmblies completed.

Ken


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## Ken I (Jan 15, 2012)

With a single elbow / piston assembly, everything seems O.K. but I have made some curious observations.

Clearly with only a single piston in you cannot rotate it fully (driving one side only) as at some point it "self-locks" due to friction - one piston starts to slide out of sync with the other and it locks.

This occurs at 47.2° at the nearside and 24.4° at the farside.

Even a "frictionless" set up will come to grief at the 90° position.

If you have a 3 cylinder motor then the farside pistons are just 5.8° short of locking as the nearside approaches 5.8° from locking - I thought the six cylinder would offer an advantage - the nearside is much improved being 17.2 ° from locking, with the farside at 17.2° from locking - so it should be better. This improvement being due to the "extra" nearside pistons coming into the wider "no-lock" nearside area before the farside (which technically remains unchanged).

In 3 or six cylinder neither should self lock but the three cylinder strays much closer to self locking conditions - I'm sure Marv could work out the angles relative to friction coeffiecients.

Again I can see how a host of evils might be avoided with PTFE pistons due to the lower coefficient of friction.

Based on these observations a 4 cylinder will not work. (Boy am I glad I didn't design that configuration only to discover this piece of enlightenment at this stage of the game.)

This applys when turning the cylinders externally - when the cylinders are acting together the vector force at 45° will drive the device.
With only one piston in I can rotate both cylinders through 360° if I apply force at 45° in the middle of the elbow.

This video may help explain what I am talking about.

[ame=http://www.youtube.com/watch?v=eqdyO4FcFS4]http://www.youtube.com/watch?v=eqdyO4FcFS4[/ame]

Well now for the drudge of making another 5 piston assemblies.

Ken


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## miner49r (Jan 15, 2012)

I'll say it again... WOW! I really like how you think outside the box with your tooling. I must have hundreds of those Stanley parting tools.


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## rustyknife (Jan 15, 2012)

Yes I noticed the self locking action as well if one cylinder was rotated. With a good lubricant such a PTFE grease and a awhile of running, the bores and pistons wear to each the binding is no longer an issue.


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## Ken I (Jan 15, 2012)

Miner, that stanley knife PO works well for some applications - the blades can be surprisingly tough - I'm cutting drill rod here.

But they will flex particularly if you put a relief on them - but good for small grooves and parting off thin walled tube sections etc.

Rustyknife, with a single piston in, if you rotate to the 90° position the "towing" cylinder is going to pull the "dragging" piston straight out - so even a perfectly machined, frictionless assembly will come to grief here. So you are always reliant on the other cylinders outside of the self locking zone to keep the motor synchronised.

My point was that the three cylinder elbow engine sails close to the wind frictionally, 4 cylinders will not work - you might get it to turn under power but it will wreck itself at the self locking points.

On rethinking 5 is better than 3 and six slightly better still although you increace your risk of problems with more cylinders.

Foozer - "experienced" elbow builder is anyone who's ever built one. 

Thanks for the comments guys.

Ken


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## Ken I (Jan 20, 2012)

Just an update - its not been a successful week.

My ER collet chuck turns out to be Chinese junk and runs out 160 microns - that's mounted on a piece of turned stock to eliminate my machine inaccuracies - my supplier has now sent me three - all useless - so I'm searching elsewhere. I can eyeball my 4 jaw to 40 microns without a DTI, so that kind of "accuracy" I can live without.

Switched to production mode to turn up the remaining 10 pistons etc.

I made four scrap pistons in a row - when changing barstock - see thread "I can't drill straight"

http://www.homemodelenginemachinist.com/index.php?topic=17258.msg177226#msg177226

Lulled into a false sense of acomplishment since the first two were OK - when I changed barstock problems set in.

Coincidence or the material ? 4 out of 4 good ones from the old material, 14 out of 14 bad ones from the new material ?

It would appear the new barstock has a corkscrewed grain due to spincasting (bad practice somewhere in its manufacture) that makes straight drilling impossible.

So I gave up and went to leaving the O.D. oversize and then mounted it on a mandrel to finish up concentric (which is probably what I should have done in the first place on a concentricity critical item like this). More bloody tooling.






Using this set up you will quickly discover any errors in your tailstock setting - corrected with the DTI and some vigorous thumping.

This set up did allow me to batch mode process one operation at a time.

TIP - only tighten the nuts with the live centre in place - to avoid bending the flimsy mandrel.






This last photo - using a DTI for my finishing cuts - get close - measure - adjust slide to DTI (not the handwheel) - gets you away from any stick slip and "feel" problems of making your final adjustment. You also want to get your penultimate cut to an exact size if you want accuracy on your final cut.

With a bit of luck (and no extraneous requests from SWMBO) I might just get to test run the motor this weekend.

Ken


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## miner49r (Jan 20, 2012)

I like your "never say die" attitude. Undoubtedly this will be the Elbow engine that everyone will be trying to top.


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## Ken I (Jan 22, 2012)

Foozer, you can have that donut now - it ran first try.

Here's the vid - note this is not finished by a long way and this is merely a trial run - none of the metal to metal surfaces or plugs have had sealant applied yet. All the mechanical seals and "O" rings are in place and the motor is taking that friction in its stride.

[ame=http://www.youtube.com/watch?v=9cpW07qEaM8]http://www.youtube.com/watch?v=9cpW07qEaM8[/ame]

It has a couple of tight spots which I hope will work themselves out.

There is too much clearance on the distributor bush (I knew this when I assembled it, the reamed hole was a bit bigger than my axle stock) and there is too much bypass leakage.
By comparison the throttle hardly leaks at all in spite of it being a metal to metal running seal.

Captain - I think you are right the "springy elbow thingies" probably introduce more problems than they solve, however the pistons being able to rotate on the elbow axles does seem to be a good idea.
So I'm going to have a go at replacing the elbows with 4mm shaft (I'll try one first).

Apart from leakage from the unsealed surfaces the "O" ring & lip seals do the job as intended and confine all leakage to the exhaust.

Note also that it seem to be running (relatively) well without a flywheel - does anyone out there think I should fit one ?

So there will be a bit more dickering before its posted as a finished project.

Ken


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## vcutajar (Jan 22, 2012)

Congrats on your elbow engine.  :bow:
Vince


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## Blogwitch (Jan 22, 2012)

Very good result Ken, your calculations worked very well indeed.

Isn't it nice when things work first time out?

This engine will work perfectly without a flywheel because both sets of cylinders do the driving, and at least two cylinders are under power at all times, so a flywheel isn't required to get it to the next power stroke, as required by a lot of engines, especially oscillators. But what about putting a small flywheel on BOTH cylinders, just for effect.

Cedge showed me an idea about one many moons ago, that was in a V configuration, but he never got around to making it. By making the correct stand and hacking away at all that unnecessary platework, just to get a bit of shape into it, yours could do that admirably, and would make it a truly unique model.

BTW, if you go into the history of these engines, they are not designed to be engines at all. They were called a Hobsons coupling, and was designed so that a drive could turn through 90 degrees without gears and also be able to swing through a complete circle with that right angled driven shaft.


John


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## DickDastardly40 (Jan 22, 2012)

Good work and a good runner.

I hate to disagree with Bogs but you do see this type of engine albeit in a bent axis rather than a 90deg configuration as a hydraulic motor. Maybe this has been discussed before and I should wind my neck in.

I wonder if it could be made with a swash plate rather than 90deg bends required?


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## Blogwitch (Jan 22, 2012)

You have most probably seen something very similar on naval helicopters on your gaddabouts, they use small hydraulic motors for folding the rotor blades, and you have most probably guessed, they are not based on this coupling principle, but a swashplate motor.

This is one being used in the correct context

http://toolmonger.com/2008/05/30/gearless-right-angle-socket-adapter/


John


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## Ken I (Jan 22, 2012)

Bogstandard  said:
			
		

> Isn't it nice when things work first time out?



Thanks John - yes the moment of truth is always a bit nerve wracking - I don't generally post anything I design until after it works to save making a prize ass out of myself.

I knew the original idea was a drive coupling, I didn't know it was called a Hobsons coupling.

Still aways to go yet.

Ken


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## Captain Jerry (Jan 22, 2012)

Ken  :bow: :bow:

Congratulations on a successful test. I think you got it licked!. Slow running, reversing, no flywheel, are all signs of a good design, well executed. You didn't make it real clear but it sounds like you also resolved the oil slinging?

A flywheel, while not really needed, will improve the slow running capability. I have not built an "Elbow" engine and like most people here, have a long list of things to get around to. I have always thought that when I did, I would like to have a flywheel on each cylinder designed as bevel gears. I would set them so that the teeth appear to be in mesh but make no actual contact which would eliminate gear noise. S Just an idea that I may never get around to.

You might enjoy this link to my first post on this forum. The angle of intersection is 72° and is also an "inside out" design. The visible rotating parts are the cylinders. 

http://www.homemodelenginemachinist.com/index.php?topic=3500.msg34766#msg34766

Jerry


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## Foozer (Jan 22, 2012)

Ken I  said:
			
		

> Foozer, you can have that donut now - it ran first try.



Good, makes that cup of coffee so much better

Flywheel? to pose as a motor Yes, as a coupler example No. I vote for Motor

Well done indeed

Robert


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## arnoldb (Jan 22, 2012)

Thm: Well done Ken ;D

Kind regards, Arnold


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## smfr (Jan 22, 2012)

Ooh, it's awesome to see it running! It's going to be a great once it's finished up and settled in! :bow:

Simon


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## miner49r (Jan 22, 2012)

There was never a doubt in my mind. Looking forward to the finished product.
I am starting to get how this contraption works. Are both cylinders under power or just the vertical one?
Alan


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## Maxine (Jan 22, 2012)

That's GREAT!


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## Ken I (Jan 23, 2012)

Thanks for the comments.

Captain - that "scratch your head and gawk" motor is exactly the sort of thing that interests me - lovely.

I think the oil problem is licked - although at the moment I'm applying lashings of oil while it runs in so its still throwing some - but once I stop applying oil to the outside end of the cylinders, the "O" rings should keep the oil in (that's the idea anyway).

Miner49r - both cylinders are powered - 180° extending and 180° exhausting (a little less to avoid overlap).

Bogs - It only just sunk in about mounting as a "V" - Intriguing idea.

I was also thinking of "Gears" on both cylinders - but I was thinking more along the lines of old style pin gears - but they won't actually touch (does make a nice place to jamb your fingers).

Ken


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## metalmad (Jan 23, 2012)

Hi Ken
That is awesome
it reminds me of a swiss watch :bow:
Pete


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## Ken I (Apr 17, 2012)

It has been nearly three months since I last posted on my elbow engine.

Once I get an engine running I tend to leave it unfinished and run it for a while and show it to friends etc - but terminal ennui sets in and it usually takes a while for me to get motivated to tear it down, attend to all the outstanding issues and finish it off.

Well I've resumed and hope to finish it off shortly.

I made the flywheel - continuing with the six-shooter theme, I made the flywheel spokes out of spent cartridge cases (I hope this isn't too over the top).

Boring the rings on the RT / minimill.






The cartidges have a draw angle on them so I could make them a tap fit and still leave wicking space for the solder.

Next assembling on the lathe to get everything concentric.





During the soldering I dropped the damn thing which knocked it out of whack (much cussing) did a fairly decent job of restraightening it (hot) and skimmed it all to run true and look good but the butt ends of the cartidges are all at slightly different heights which is going to annoy the hell out of me - but I'm not going to remake it.

All polished up and fitted to the engine.






I have decided to lay the engine down in an eliptical wooden base (next step) and I am going to hack away some of the platework upright (as suggested by Bogstandard) to pretty it up some.

Ken

PS I've switched to Imageshack as Photobucket is frequently unavailable.


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## lazylathe (Apr 17, 2012)

No pictures on this side Ken....

Looking forward to seeing them as it has been a while since you worked on this engine.

Andrew


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## arnoldb (Apr 17, 2012)

Hi Ken

 No images here either.

I had a quick look at your post's source - the image sources come up like this: 

```
[img]http://=http://img10.imageshack.us/image10/2103/eb6fwb.jpg[/img]
```
The wrong part is the first *http://=* - that shouldn't be there.
I removed those bits for now.

Not that it matters much for me... Imageshack does not allow any of my local ISPs to access photos  - I just get to see yellow frog pictures, so just check if other people can see it now.

Kind regards, Arnold


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## Foozer (Apr 17, 2012)

Now thats a nice looking flywheel.

Robert


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## Ken I (Apr 17, 2012)

Arnold,
     Thanks - all sorted - its very fussy about syntax - once I cut and pasted it it all got sorted and I can see the pictures as opposed to the damn yellow frog - that must be really annoying for you.

Fooser - thanks, I like the way it came out but it might not be to everyone's taste.

Ken


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## arnoldb (Apr 17, 2012)

;D That's looking great Ken :bow:

Definitely not OTT - just very unique!

And thanks; I don't know what you did with Imageshack, but it now allows me to see the photos.

Kind regards, Arnold


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## mklotz (Apr 17, 2012)

So what caliber is your engine?


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## Ken I (Apr 17, 2012)

45 - Go ahead - make my day.

Actually they're 7.62 NATO rounds - but the butt end is the same as a 45 auto - the rifle rounds gave me a bit more length to play with.

More correctly the pistons are 10mm diameter x 30mm stroke.

Ken


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## lazylathe (Apr 17, 2012)

WOW!!!
That is a cool looking elbow engine!
Quite possibly the greatest example of customization!! ;D

Now how about a video of it running?

Andrew


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## Captain Jerry (Apr 17, 2012)

Ken

That's a good looking engine. I'm not much on guns but I appreciate the integration and style. I agree that the angular plates seem a little out of character. Your plans to change that will help bring it together. 

I like the reverse control but I am a little puzzled as to the circumstances that would require a reversing revolver.

Jerry


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## Ken I (Apr 18, 2012)

Captain Jerry  said:
			
		

> I am a little puzzled as to the circumstances that would require a reversing revolver.



In case I ever get sent to a backwards universe by my improbability drive of course.

Andrew - there is a video of it running on page 4 but I will post another (better) vid once I've finished all the detail work.

Regards,
      Ken


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## lazylathe (Apr 18, 2012)

Thanks Ken!
Checked out page 4 and it is a real smooth runner!
Another winner!! ;D

Andrew


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## vcutajar (Apr 18, 2012)

That's the word I was looking for - unique (thanks Arnold). It will surely stand out. Great work Ken.

Vince


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## Ken I (Apr 22, 2012)

Next a presentation base - a local shop that makes solid wood furniture donated this lump of rough hewn oak.







This is what was lurking inside it





And how it got there





A 1:1 stick on print being my marking out method.






Cropping out the cutter radii using a morticing machine chisel.

Test fitting.






Note I have reversed the inlet and exhaust ports - see bronze muffler / exhaust below throttle (not a good idea for steam).
Next tear down the motor to modify / repair / pretty up.

Ken


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## miner49r (Apr 22, 2012)

What else can be said? Give yourself a nice pat on the back.
I look forward to the final video.
Alan


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## Ken I (Apr 22, 2012)

Spent the weekend "hacking" away at the upright to pretty it up some.






This is the MT2 stub turned from Aluminium to get it on centre.






Then did a spot of engine polishing.






A 18 diameter wooden dowel with a leather disk glued on it (the dowel on its own didn't work well), Locktite fine grinding paste and WD40 @ 9mm pitching worked from the centreline out.

Also the upright with the linear pitching lined up with the circular pitching.











Damn - the plugged error holes are still visible - so I'm going to make some sort of ornate cover plate to close this over.

The brass inlet port is scewed into the base - piped from there to the inlet inside the base.

Just have to remake the timing bushes - there is too much clearance on the originals leading to a lot of bypass air.

I'm thinking of painting the steel base rings in hammertone black.

Ken


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## Ken I (Apr 24, 2012)

Decided to make a cover plate to hide the bolts and access holes.




This pushes in and is held in place by the friction of an "O" ring.
Since I didn't have a piece of stainless large enough I made it by silver soldering a piece of shaft onto a stainless plate.

At this stage it is simply polished - I'm thinking of circular polishing it as well or is that turd polish as Bogs might say.

Comments - leave it polished or go circular polishing ??

Ken


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## Captain Jerry (Apr 24, 2012)

Ken

That cover is a very nice, subtle piece of dressing and the soft edge blends nicely to the rounded frame. This engine has enough visual appeal in the cylinders and flywheel that more might be too much.

One other point about turned faces. They hide fingerprints but if they are scratched, refinishing is all but impossible. If left smooth polished, you can buff it up in a few seconds. 

Either way, it is a fine piece of work that will get a lot of attention.

Jerry


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## rhitee93 (Apr 24, 2012)

I like the engine turning, but I think you would be better off with the cover plate polished since the piece it attaches to is already engine turned.


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## dgjessing (Apr 24, 2012)

Beautiful! I vote to leave the cover plate polished - plenty of engine turning in there already. :bow:


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## vcutajar (Apr 24, 2012)

I would leave it polished.


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## Ken I (Apr 24, 2012)

O.K. Polished it is - thanks guys.

I'm busy reassembling the engine and sealing up all the metal to metal joints and gallery plugs none of which have been properly sealed yet.

I discovered one of the thrust bearings to be jammed solid - because of a minor dimensional error - so the one cylinder was rotating without any assistance from this bearing - on the butt end of the seal - I'm surprised it ran as well as it did.

I should finish tonight but I'll give all the sealants 24 hours to cure before applying pressure. 

Ken


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## kustomkb (Apr 24, 2012)

Very nice engine Ken, a real beauty!

A well thought out re-design too.


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## Ken I (Apr 25, 2012)

O.K. the motor is all back together (picture to follow) - it ran first time without any problems after reassembly so I'm calling this project finished.

I'm going to run it for about 8 hours to see what happens and will post a video Sunday or Mondayish. (Its now 10:00pm and I don't want to irritate the neighbours with my compressor which is very noisy - so I've stopped for now.)

The motor runs at 300rpm flat out - small pipes etc. - could probably goose it up to 1000 but that's not the point.

At the moment it will run at a slightly hesitant 100rpm because of a slight tight spot which I trust will run itself out. I'm hoping to get down to 30rpm.

With the exhaust connected to a pipe to duct it elsewhere, so I can check (listen / feel) for leaks, the motor simply purrs along like a contented cat.

It does not leak - but that was the entire point of the exercise. I have noticed two of the cylinders leak slightly at the stall / start position but don't appear to leak when running - I did not use a lot of "O" ring interference and obviously the rings are taking a pasting during run-in - so I'll probably treat it to a new set of "O" rings once run in.

Under running conditions, the only place air (and therefore oil) comes out is the exhaust - again that was the design intention.

As I am still applying upper cylinder (externally) lube for running in, it is still throwing a little oil (very little) but once run in that should be a thing of the past - again that was the design intention.

There is still a small bypass leak (from the metal to metal clearances at the throttle and distributor axles) but its small enough and I can live with that - again - it goes out the exhaust - nowhere else.

I will now finish off the drawings and build notes to file under downloads when I will also file it under completed projects.

Give me about a week to get my sh.. together (if you are interested).

Ken


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## bearcar1 (Apr 25, 2012)

Interested indeed Ken. Can't wait to see the final video of this one running on just a whiff. The embellishments you have done to this engine, not to mention the overall re-design are outstanding. I imagine you are glad to have this one behind you now and can finally relax and begin plotting the next 'ultra'-engine. ;D

BC1
Jim


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## Ken I (Apr 26, 2012)

Here's the completed elbow engine.






And a "prequel" video of it running - I piped up the exhaust so you can hear it without the exhaust noise - but the clatter you can hear is rain on my IBR workshop roof.

You can see the slow running hesitancy at the tight spot which I am hoping to run out before posting a vid under finished projects.

http://www.youtube.com/watch?v=X0-vCBC0KkU&feature=youtu.be

Ken


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## vcutajar (Apr 26, 2012)

What can I say, just amazing. Well done. :bow: :bow: :bow:

Vince


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## arnoldb (Apr 26, 2012)

:bow: :bow: Very nice indeed Ken; great runner.

 : If it's raining in CT, there's cold weather on the way here to Windhoek... I guess the Winter's arriving...

Kind regards, Arnold


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## clivel (Apr 26, 2012)

arnoldb  said:
			
		

> : If it's raining in CT, there's cold weather on the way here to Windhoek... I guess the Winter's arriving...



I used to think it rained a lot in Cape Town, but that was before I moved to Vancouver 

Ken, I have just finished reading this thread, what an amazing build, but so intimidating for a beginner.


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## Ken I (Apr 27, 2012)

The motor has about 8 hours run time on it and the tight spot is loosening up, it will now tick over at 50rpm. My target is 30 or less.

Clive, the "Elbow" intimidated me given all that I'd read - but at the end of the day its a collection of parts which individually are not that difficult.
There are a few things that you have to get right and it was a challenge.

But a fun challenge.

Captain Jerry, the oil flinging problem is almost licked - oil still works its way past the piston "O" rings (it ultimately has to or the "O" rings wouldn't be lubricated) but the amount is very limited and tends to accumulate around the mouth of the cylinder bores. If you wipe it away you can get maybe an hours run time without any oil coming off.

Ken


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## Captain Jerry (Apr 27, 2012)

Ken I  said:
			
		

> Captain Jerry, the oil flinging problem is almost licked - oil still works its way past the piston "O" rings (it ultimately has to or the "O" rings wouldn't be lubricated) but the amount is very limited and tends to accumulate around the mouth of the cylinder bores. If you wipe it away you can get maybe an hours run time without any oil coming off.



Ken

Licking is one way to solve the problem if you can get past the taste. You might try flavored oils but they tend to be a little sticky.

But I think you have the problem solved. As the engine wears in and smooths out, it will require less oil for lube and sealing and the o-rings will leave less oil on the cylinders. You should be able to get several hours of run without licking.

Looking at this engine, it is easy to forget that your motivation in building it was to solve the many problems of the original design with solid engineering instead of fiddling. Nice going!

For newcomers to this thread. Don't just look at the video and say "wow-elbows, and its shiney!". Go back to page 1 or 2 of this thread and get inside the design modifications. That is where the real beauty is.

Jerry


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## Ken I (Apr 28, 2012)

Captain, Thanks for the kind remarks - but an even bigger thank you for your hand in this process.

I have posted it under finished projects and I have completed all the drawings and build log - but the downloads section is being cantankerous and I've handed it over to Bob to sort out.

Regards,
      Ken


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## Ken I (Apr 29, 2012)

Here's a "prettier" video of it running.

http://www.youtube.com/watch?v=WHhnuLk15SY&feature=youtu.be

Ken


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## Ken I (May 1, 2012)

I have posted the drawings as a *.zip file under the downloads section if you are interested.

It contains an Autocad 2D *.dwg & *.dxf file with each part drawn in a different layer / colour.

There is also a single sheet *.pdf of the same.

At this time the downloads section will not accomodate the large (5MB) *.doc file of build notes and photos.

(The download limit seems to be 2.5MB not 25MB as stated)

If you would like a copy of the *.doc file, send me a PM.

Regards,
      Ken


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## Ken I (May 8, 2012)

A final postscript to the Six Shooter saga.

As regards the stiffener (between the two elbow axles) - I removed mine (as an experiment to see what would happen) from my elbow engine and it still turns over by hand and runs - pretty much the same as with it.
It sounds a little more "grumbly" when running so the reaction forces are probably springing the 90° slightly and my "springy elbow thingies" are taking care of it but at the expense of some increaced side load on the pistons.

I did this experiment to satisfy my curiousity in response to Captian Jerry's Swinging Elbows thread.

FYI

Ken


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## coffeebobby (Jul 30, 2018)

Hi Ken, is the porting on the base the same as 3 piston models. Regards, Bob


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## Ken I (Jul 31, 2018)

coffeebobby said:


> Hi Ken, is the porting on the base the same as 3 piston models. Regards, Bob


No - the porting is via the central shaft rather than the base - but is fundamentally the same tining - for half the revolution it is ported to inlet and for the other half to exhaust (with obvious gap to prevent blow by).
This was my fundamental change to eliminate the troublesome bleeding at the base unless the clearance is very closely held.
Also to eliminate the "throwing" of oil which has ruined a great many shirts during elbow engine displays.
You can download the plans off the download section in PDF or ACAD Dwg (currently at page 6)
A pity about all the missing photos due to Photobucket management having lost their mind.
Send me a PM and I can send you the MS-Word *.doc build notes if you are interested.

Regards, Ken


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## Cogsy (Jul 31, 2018)

Ken I said:


> A pity about all the missing photos due to Photobucket management having lost their mind.


I hadn't seen this build before - fantastic job. I had a look back through the thread and all the Photobucket pictures appear to be displaying (I hear Photobucket have now reversed their disastrous decision) but the pictures stop where you announce you've changed to imageshack instead, which I think also went the fully paid route. Not that I'm recommending Photobucket after what they did, but at least some of the old threads that were destroyed are now visible again.


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## ThomasJ. (Aug 1, 2018)

After five attempts to get one running the magic happened and the shop was well misted from the spray! So how to share the joy and keep friends clean ? I put a gear motor under it and pulley drive. It has been displayed in homes and no complaints of over-spray ! It is really interesting to watch.


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