I have this old machine. It has a gear on a shaft, and the shaft had been bent. The gear was pinned to the shaft by a transverse press-fit pin which was filed so smooth I didn't even see it for a long time. I guess this was an old way to make the joint. Anyway, I removed the gear and have a new shaft. I had been going to just machine a 3/16" keyway and stroke an inside keyway in the gear, but someone on this NG said don't do that, pin the gear back on the way it was since the pin may be stronger and also may shear in the event of a collision.
I haven't had any time to work on that machine in the interim, but it's coming up in my queue shortly, so I'm starting to think about it.
Where would I get round key stock? I don't know the size offhand, might be5/16", might be 3/8".
I'm a little leery of pressing a pin into a hole in a hole, if you know what I mean. It's tough enough to put a cotter pin through sometimes, let alone a press-fit pin! Anyone have any bright ideas? To be more specific, let's assume it's a 3/8" pin, and the hole in the gear is 0.374" and I drill and ream the shaft to 0.374" also. Then I put the gear on the shaft and look through the hole and tap it around as best I can until it looks pretty good, then I put the pin's tapered edge in the top of the top hole in the gear and press with the arbor press - what if the holes aren't aligned right? Worry, worry ..