Posted by Ian Johnson 1 on 24/09/2020 21:57:51:
… That's a nice little engine, but only run for a few minutes! maybe that's why the plans were free? But I'll probably go with the plans I have and see how it goes.
IanJ
I admit to being a Jan Fan, but I doubt the trouble is with his plans. Jan's published many interesting engines, and some of them are difficult. For example, my first attempt at his Coffee-cup Stirling didn't work until I'd fixed all the tiny leaks and reduced friction at all points to the minimum. As built the engine didn't run, several hours later it did. Same design, same parts, but everything freed-up, flywheel balanced and the timing adjusted. Initially reluctant to start with run times in minutes, now it runs on an electric element for hours on end.
I noticed, in the failed state, that brass parts corroded, cause unknown, maybe heat, condensation and oil coupled with acid fumes from the sealant. The problem disappeared after the engine ran properly. Delicate engines may need repeated cleaning in the early stages: apart from debris due to machining and parts wearing in, if they're not working properly oil gums up, liquid collects etc etc.
Also a fan of Stewart Hart's Potty Mill engine. It's much less fussy and you can squirt high-pressure air into it. Provided the timing is right, and the parts turn freely, even a high-friction build will run. I found it a good balance of challenges. Made me think but none of it was too hard for this beginner.
Dave