WALKING BEAM STIRLING, daryl boyd plans.

[jct842]

I have started with construction. made the displacer piston, "don't use air to blow out the tomato paste!" took top off the 7 3/4" paint can. plans specify using a 1" power piston. What I have is a hard copper 1/2" tube for cyl that is actually closer to .6 ID with a sliding fit brass tube to make piston out of.

How much will the reduction in piston size effect operation? I have thought of using 2 of them side by side if I had to. John

 

[RichD]

Hi,
I built one from Daryl's site and used 1" copper pipe and 1.25" stroke. A 1/2" cast iron pipe cap fitting turns down nicely for a piston. Mine runs well but takes a lot of heat to get going.
Rich

 

[rake60]

I can't really answer your question John, but I did build that engine some time ago.

http://www.homemodelenginemachinist.com/index.php?topic=4328.0

I cheated on the pistons...
I went to the local auto parts store and bought THIS
drum brake wheel cylinder.

It had two perfect 1" pistons in it that were modified for the need at hand.

I just realized that cast iron housing looks a lot like a steam engine cylinder.
Off to the shop to tinker!

Rick

 

[jct842]

I am making progress with the engine. have completed the cans and drive piston. the drive piston is out of brass tubing with the bottom soldered in and a flat brass piece to hold the con rod. is probably way lighter in weight than I could have got turning anything. am working on the wood support for flywheel which is a vcr head. so far I can not detect any friction from either piston to speak of. This thing is turning out huge but is going to be very easy to make any adjustments necessary. will have pictures once I have it running. john