Taking a break from the "ELBOW"

[Ralph]

Well, after doing battle with the elbow engine for a couple weeks I thought I'd give it, and me a break. Maybe a different perspective will help at a later time. Anyway, so I didn't get bored I threw this little thing together.
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[1Kenny]

Thats cool, Ralph.

I am down to drilling the air ports on my elbow but have been too busy this week.

 

[rake60]

Nice little engine Ralph!

Rick

 

[Cedge]

Ralph
Hang in there.... it'll come together. Mine was put on air today and I'm now getting sporadic bursts of powered movement. I'm having to tweak the squareness of the pistons even tighter than I'd have thought . The tolerances are tight on the drums and it appears even the slightest bit of angle has to be beaten out.

I've just had to remove two piston sets and adjust them by feel rather than by sight. Each time, a little more friction disappears and the binding at full extension gets less and less. I'm close enough to smell success, but the little devil hasn;t given up yet...LOL.

I made a small modification that might prove to be worth consisering. The ends of the pistons were binding against the cylinder walls due to my having shortened them, trying to avoid their striking the valve plate. I managed to get them far too short in the process. This only became obvious when they began to "droop" when at thier highest point. this cocked them into the walls and caused the binding problem.

The solution I came up with was to chuck the pistons back in the lathe and center drill the ends. I then press fitted a small brass button measuring 1/4 dia x .150 in. and dressed the edges. This gave back the lneeded ength and added a nice brass bearing surface at the ends of the pistons. Once these were massaged a bit, the binding was reduced significantly. The brass also provided an easily replaceable wear point.

Now if I can get past the problem of having an air compressor that's too small to keep up with the demand, I'll eventually whip this project and begin looking for the next one. Help!!.... I'm hooked....LOL

Steve

 

[Ralph]

Thanks Kenny,Rick, and Steve. I'm not ready to admit defeat just yet. I keep tweaking and adjusting and most importantly reading everybody elses ideas on what makes these things tick. I too shortened my pistons and experienced some slop at the end of travel. I think I'll try that brass button approach. Certainly cant hurt. Tomorrows another day !!!!!!!!!!!

 

[Ralph]

Oh about your air-compressor problem. I can feel your pain. I managed to throw the connecting rod through the side of mine. Another project

 

[lugnut]

Steve, I think your brass button thing might be the thing that keeps my elbow "RACHAFRACHER" out of the scrap pile, Thanks
Mel

 

[Ken_Shea]

Ralph,
I am just unable to watch those little engins run with out a getting a smile on my face.

Good job.

Ken

 

[bronson]

Hi ralph I just finish that same engine and it was my best running engine to date really enjoyed builting that one. Good luck on the elbow engine.