[GB SISSON]

Got the teflon rod yesterday, made a bunch of buttons. It machines better than the wood. I few tech questions arise as I assemble the first piston/rod assemblies. The rod is exactly .750 and so the button heads are a pretty tight 'tap with a hammer' fit. This makes me confident in some ways, but they most likely wont rotate. My tenons or stems are also a tight fit into the wrist pins. This combination will in my opinion lock the pin to some extent and make it act more like a fixed pin. Still not so bad for wear and longevity of the buttons. I can easily make the heads a bit looser so they rotate with the pin, keeping them tight with the pin if that's better. The other thing I notice is the holes through the piston must be offset as in all 4 assemblies I have done, the buttons are slightly proud of the piston on the marked forward side. Not much, but noticeable. A tighter radius to the domed end will correct this. I capped a couple of wrist pins with my buttons and placed them in the bores just to see the clearance and see about .008 total. If I keep the button head 'hammer tight' in the piston it seems like they will stay centered better and not rub the cylinder walls, but this is at the risk of stopping or slowing the free rotation of the pin in the piston. On one trial fit I made the button head about .001 under the size of the wrist pin and it (the double buttoned pin) just presses through the piston and rod with hand pressure. Is that preferable to tapping in the buttons hard after the rest is assembled. I could be over thinking this. I have been known to do this. Thanks in advance for any help. GB