Elmer's #24 Beam Engine

[EricB]

Thanks for the comment!

This is my solution for the boring valve linkage. In progress. I'm trying to make it look closer to the larger beam engines. I made the eyelet end first then turned down the shank. Not perfect but better than I expected. So far.

Eric

[EricB]

More of the valve linkage.

[samc88]

Nice work Eric, they look really tidy

[EricB]

Thanks for the comment!

I finished the top of the spool valve and made a simple fixture to align the valve links while soldering. It worked out well. I also made another eyelet for the top of the piston rod and got that assembled.

No more soldering, which is a good thing as I spilled the bottle of flux on my workbench.

There are still a few more tiny bits to sort out but all the major stuff is done.

Eric

[EricB]

It isn't finished yet but I had to put some air through it. Tomorrow will be 3 months working on it.

No sound, I had the compressor at my feet, but if you could hear it there's a knock when the crank is near the bottom.

<a href="https://www.youtube.com/watch?v=qhz17qWK31E" target="_blank">http://www.youtube.com/watch?v=qhz17qWK31E</a>

[ShawnColorado]

It could be that the connecting rod, that connects the piston, on the opposite side of the beam is a tad to long and it causes the piston to hit the top of the cylinder cap.  This would be true if the noise only comes when the crank disc is at bottom dead center.  The other possibility could be that where the con-rod attaches to the beam, it was drilled a little long on the beam, which could increase the stroke and cause that same tapping on the cylinder cap.
Just some thoughts....
ShawnColorado

[crueby]

Agreed on the possible causes. I'd  try turning it over by hand and when it gets close to that point hold the flywheel steady and wiggle the other parts to see what is hitting or has slop in a joint.


 

[EricB]

When I first tried to run it I had the piston hitting the bottom of the cylinder. I adjusted the connecting rod to get equal clearance at each end of the stroke.

I'm thinking the knock could be from lack of side clearance between the crank and connecting rod, or the eccentric strap. If I spin the flywheel by hand it sticks where I hear the knock.

[crueby]

You could disconnect joints one at a time to help isolate the knock, maybe?

[EricB]

You could disconnect joints one at a time to help isolate the knock, maybe?

It's the eccentric assembly binding. It doesn't have any method of keeping the parts centered on the big end, and the side movement makes it lock up. Without the strap the rest works smooth.

I wasn't happy when I made the parts in the first place.

Take three...

[EricB]

Here is is again. I figured out the binding problem with the eccentric so no redesign yet.

<a href="https://www.youtube.com/watch?v=1z33tSFzT90" target="_blank">http://www.youtube.com/watch?v=1z33tSFzT90</a>

Eric

[crueby]

Great!

[Dave Otto]

Nicely done!

Dave

[bent]

That looks and sounds perfect! 

[EricB]

Thanks for the comments!

Since I changed the link at the top of the piston rod I could not use the plan method of holding it in place. The pivot pins for the beam and the top of the connecting road were to be held by closing the holes with a punch I guess. I didn't like that either. I considered using bolts, and after much thought decided to make threaded pins with a screw slot so they could fit almost flush with the parts they secured. That entailed resising the pivot holes in all the affected parts for to the size of the new pins and tapping the sides that receive the threads on the pins.

The plans still call for a pinned collar to secure the bottom of the connecting rod, and a hole and pin to secure the small end of the eccentric strap.

Nearly done.

Eric