Thereīs another build of a very similar thing atm in HMEM, by max corrigan. Far be it from me to try to steal anyoneīs thunder, Iīll post my widget here. Itīs perhaps also more appropriate here, since I modded the original design to suit what material I had in hand, and to get an even faster runner. These things run real fast, given a pressure of some 50-60 psi (4-5 bar).
side view
As you can see, it has a simpler linkage between the eccentric and valve, to not to rob power in the linkage mechanism. The valve, which is a 8 mm stainless bar with two milled flats, does not really rotate, it swings back and forth in some 75-80 degree arc, like a windshield wiper axle. A lot faster, though.
Also note the "intake manifold", far simpler than in max corriganīs engine. Itīs just a flat brass bar with a milled cavity inside, to furnish air (steam) to the cylinders.
The puny flywheel has an alum. center and a press-fit bronze ring around, to give some swing mass to it. Way cheaper than a full bronze/brass disk (miser, miser)...
Thereīs also interference-fit bronze liners in the cylinders, similar to Rudy Kouhouptīs compound engine, from which I copied the idea. I built that before this gadget, and bronze liners work real well with alum. pistons. The pistons have grooves (one each) filled with graphite yarn, also suggested by Rudy K. Iīve used also (plumberīs) teflon tape for similar purposes, itīs a good alternative. Graphite is way dirtier, though
Another thing you canīt see are ball bearings, they make for a very freely rotating engine. It turns 3 full rotations at a flick of a finger.
You might notice also the "balanced" crank cheeks, the plans call for round disks. Theyīre not really balanced, but I first made them round, and the machine walked right off the table when I gave it some compressed air. So I cut big chunks off both sides of the crank pins, and now at slow speeds anyways, it stays on the table without clamps or screws.
Iīll try posting a video sometime soon, running on compressed air, I donīt have a steam boiler. But I donīt see any reason why it wouldnīt run on steam as well. The only possible rusting parts are the ball bearings and the fly wheel attaching screw. All other steel parts are stainless.
As a side note, I attached this to a hard disk spindle motor, running as a generator. Old hard disks ran at 5000-something rpm, and used 12 V for the spindle. To run one as a generator, you must give it at least the same 5000 rpm, and not expect anything like 12 V back, more like 4-5 V, if that. They must run very fast indeed to get
12 V, Iīd say well over 10 000 rpm, but thatīs just a guess
And the amps are very meager, just some mAīs.
I have a good stock of huge 10 mm LEDīs that need at least 1.8 V to give any light, with a 1.5 V battery thereīs no emission at all. I connected one of those to the HD motor/generator and gave the engine some (= a lot of) air. To my surprise, the LED lit up, flickering (the HD generator put out AC), but VERY bright, and after some 5-10 seconds it went off, never to light up again. Hm. I connected 3 LEDs in series, gave gas again, and I had 3 LEDs flickering
That wasnīt for very long, though (several minutes), the engine would need oil (WD-40), and thereīs no provision for it when running. But it was nice to see anyway
