Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I have mentioned this awhile ago about the necessity to prevent the piston pins scraping against the cylinder walls. I even found this problem in a couple of full size H&M engines that I have.

I punch out some disks from heat resistant trays the frozen food dinners come in. Using a hand punch, either sheet metal or leather, makes it easy. There usually is enough room to place them on the ends of the piston pins.