cfellows

I ran across this video on youtube and was impressed with the way it runs and sounds. Also liked all the movement so thought I'd take a whack at making something similar.


This is a drawing of what I have so far. Not complete, but gives you a good idea of what I'm aiming for.



So far I've got the flywheel turned and the 2 cylinders made. The latter are made from aluminum tubing, 1 1/16" OD x 15/16" ID. The flywheel is from Martin Models and is 5.5" diameter.



Chuck

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Path

Chuck ...

This going to be a fun project to follow.
In fact, I would like to make one. Anything I can do to help?

Pat

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cfellows

Thanks, Pat, think I got everything under control for the moment.

The original engine shown in the video uses rotary valves in the crankshaft. In my engine, the valving will be operated by the cylinder. As it moves from one end to the other, it will push the piston and the hollow piston support shaft left and right to alternately connect one end and the other with the air supply coming up through the end supports. Although not shown, I will have to install stops on each end to limit the axial travel of the piston support shaft.

Here is a picture showing my current plan for the air supply and valve operation. I have some concerns about my ability to get the piston support shafts to move freely left and right and still seal well in the end supports. Have to see how that goes. My engine will be reversible, and, although it should be self starting, I'm guessing it will always start in the same direction it was last going.



Chuck

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lathe nut

Chuck that is neat, depend on you to find something like that, explain it so easy then draw it, that is so good of you to share your knowledge and great skills, here I go again another copy and paste for a future project, thought that I could get you and Brains projects done in a few hundred years now looks like its going to take several thousand, will follow this one, thanks, Lathe Nut

Captain Jerry

That is a really interesting design and your innovation of moving the valve rod by piston contact adds to the interest. It also adds to the number of problems to overcome, but that's the whole purpose of this activity (I hate to use the word "hobby"). This project will keep you thinking and will keep the rest of us entertained. I had been trying to figure out the purpose of the o-rings in your first drawing. Did not see this coming.

I know how much you like the exhaust puff of poppet valves and this design should lead to a really sharp PUFF!

Jerry

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cfellows

Thanks, Lathe Nut. I'm always looking for ways to simplify things, so projects can get done quicker!

Thanks, Jerry. The purpose of the large o-rings is just to cushion the cylinder contacting the piston and sound of metal on metal.

Chuck

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BillTodd

Chuck,

Have you considered closing off the exhaust hole inside the cylinder (i.e. moving the exhaust hole further away from the piston so it's partially covered by the cylinder gland) to provide an air cushion instead_of/as_well_as the o-ring?

Bill

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Bill

Florian

Hey Chuck

You may also find that one interesting:

Cheers Florian

cfellows

That is a possibility worthy of consideration.

Thx...
ChuckThat's a pretty engine. Uses a more complex valving operation, tho.

Chuck

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So many projects, so little time, not enough energy...

cfellows

I got some more work done on my engine yesterday and today. I've been working on the design as well as some house projects, so haven't spent much time in the shop lately. Hopefully I can start getting really serious about this engine.

Here is the engine base. It's a piece of aluminum about 8" long, 2.25" wide, and used to be about 3/8" thick. However, it had a bit of a bow in it, so I flattened both sides with a flycutter in my end mill. It's now about .335" thick, but it is nice and flat. I will probably cut down the length some.



Here are the cylinder assembly support blocks. I gang drilled the holes to make sure they were in as perfect alignment as I could get them. They are 2" wide, 1.375" tall, and 3/4" thick.



Here is a partial assembly of what I have so far. The cylinder support rods are 3/8" diameter. Probably could have gotten by with smaller rods, but didn't want to push it. I'm quite happy with the alignment and the fit of the cylinder support rods... nice, close sliding fit. We'll see if that's still the situation after I screw the end blocks to the base plate...



Next, I will fasten the cylinder support blocks to the base plate. Once I get all the air passages and mounting holes drilled in the end blocks, I may mill them down some so they don't look so "blocky".

Chuck

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So many projects, so little time, not enough energy...