It's almost a year later. I took my P5 apart and replaced the diaphragms (what a funny word) and in being forced to rebuild it, I learned how it operates and which way to turn the thumb screw. (clockwise on the thread increases the cut-off pressure--again, so "obvious" nobody said it) I have it set again at 30psi, and Cecilia with her Microcosm M29 is ready for another splash. I followed Rafael's steps, easy.
I didn't see a pack of spare diaframs (there, much better spelling) offered from Jim, so I wrote and asked and he is supposedly sending me 6 pairs for $25US. I didn't attempt to obtain nitrile and make my own-- who could make replacements at $2 a pop?
And now Jin has the P5B-- does anybody have that and does it work? Looks smaller/simpler. I wonder, probably has the same life limitation as the P5? But maybe it has only a single diafram. Experience, anyone?
BTW back to the thread start-- I see Q3B and its reverser valve looks sweet. I looked at the Q2 but it is sold out, and was pretty expensive anyway. Nice on-line video of it. Q3B seems a little expensive as well, in my opinion.
But who knows what Jin's M36 engine does? It sure looks like the MSM Avon but bigger. B x S is 10 x 12mm; He says displacement is 7.6cc but I calculate r2 x pi x L x 2 x 2= 25 x 3.14 x 12 x 4= 3.76cc , or what did I do wrong? Seems like a deal for only $210 and free shipping to US. I cannot find a video of it, or anyone's experience with it. The reverser valve looks like a nice tight fit, no leaks up there. And the outrider bearing looks very substantial. This ought to be a winner, why not?
http://www.microcosm-engine.com/m36-new-twin-cylinder-oscillating-engine-p-166.html#.YItwFi9h1QM-Carl