Round ports will work fine.GreenTwin, may I ask why the inlet and exhaust ports on that engine are the shape they are? Would they also work if they were just round?
For very small ports, it is tricky to get an accurate shaped and located port, and I generally use round ports, which is what I used on my green twin oscillator.I enjoy filing, but it's hard on my hands, especially needle files, so I avoid it when I can. But it might be worth a go.
I have not seen that design.GreenTwin, I take it you've seen the magnetically sprung wobbler https://www.homemodelenginemachinist.com/threads/magnetically-sprung-wobbler.28961/ I'm thinking of trying that idea out on your engine, but I think I'll build another simple wobbler with one to see if it works. If so, then I'll be starting on your design.
Guess I'll have to start another thread for that one, lol.
But the sewing machine and the typewriter of two works of genius. How the sewing machine works by putting a loop over the bobbin is more complicated than an engine.I think the No.02 Cretors with the smaller base looked better.
I think those slotted screws are original Cretors, but I must say I am not crazy about the looks of those either, although they are the original look of that engine.
Slotted screws look too much like sewing machine parts in my opinion, but to each their own.
I prefer the old style bolt look, which had a taller head than a new bolt.
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My guess would be under the "ENGINES AND DOWNLOADS" banner, under the "ENGINES - Engines made by the member".Nice engines, but to be honest, I prefer the look of your father's engine. Also, it would be an easier job to fabricate the base as I don't have any casting equipment, yet.
Where would be a good place to start a new thread for this? I'm seriously thinking of doing a better job on logging the work I do. Some of which is doing some pretty heavy reclamation of old CI scraps.
(Edited to change a word to something more appropriate)
I still don't understand how the loop/bobbin thing works, even when I am standing there looking at it.But the sewing machine and the typewriter of two works of genius. How the sewing machine works by putting a loop over the bobbin is more complicated than an engine.