Inside-Out Steam Engine Model

This is a two cylinder (twin) reciprocating model steam engine. It's unusual in that the pistons are fixed and the cylinders reciprocate. The engine has a bore of 3/4" and a stroke of 1.75". As the cylinders move from end to end, they engage and move the piston / rod assemblies to switch the air supply from one end to the other, thus acting like valves. At the same time, other end is connected to the exhaust port. This is a double acting engine so it has 4 power pulses per revolution. It will run in either direction and is self starting although it must be manually reversed by spinning the flywheel one revolution in the new direction.

Overall length of the engine with base is about 15 inches. The flywheel is 6 inches in diameter and was milled from a solid disk of brass. Crank disks were also milled from brass and the connecting rods from aluminum. Cylinders are 1.125 inch diameter brass about 2 3/8" inches long. The rods supporting the cylinders are made from 3/8" drill rod. The compressed air is supplied from the ends of the cylinder support rods through 1/8" axial holes which exit into the cylinder through radial holes near each side of the piston. The wooden base is made from birds eye maple, the engine base is 1/4" cold rolled steel and the cylinder support columns and base are made from aluminum.

Category:

Science & Technology

Tags:

• inside-out
• model
• steam
• compressed
• air
• engine
• hit
• miss
• twin
• two
• cylinder
• double
• acting

[nrowland56]

Very nice!

Just curious with that valving, will the cylinders will oscillate with out the con rods?

[cffellows]

@nrowland56 They would if the cylinders had enough momentum. I haven't tried it though.

[davidahtes2012]

Beautiful finish,and lots more action than stationary piston and steam chest! Great job!

[ankur261995]

how does it works???

[Dividedhead]

Very nice indeed. The valving works well.

It really wants to go places when you give it some power doesn't it!?

[hheywire]

1st to comment! man that is amazing!