How did this happen? Bent gear shaft...

[WobblyHand]

Not a bad idea, it turns out, although I did lose an end mill doing it. Breaking the mill, was my fault. Tried to plunge mill with a 0.250 end mill. For some reason it didn't want to cut at some point, pushed it a little further and pop goes the carbide end mill. I was withdrawing the mill after going 40-50 thousandths, cleaning off the fine chips and plunging back in. After cleaning up the carbide carnage, I used a cheap carbide 1/8" end mill to drill deeper. This time, I maxed out the mill RPM. Should have done that with the 0.250" end mill, but forgot. Yet another expensive lesson. The 1/8" cutter cut to depth easily. Then I followed it up with a cheap 0.25" HSS drill to depth. Followed that drill with a 17/64" HSS drill. Moved the mill table over to the side and tapped out the pin with little effort. Success!

After some cleanup, I look in the hole and find some white paint - the same color as the outside. Maybe that's why it was really tight. Other than that, the bore is clean, my drilling didn't touch the bore. Somehow I have to strip that paint without messing up the bore. Anyone have recommendations for what strips off Chinese paint on mini-lathes?

Following that, need to repaint and "assembly is just the reverse of disassembly".

 

[Tim9]

No spare toaster oven. Not been feeling to well this past week, so not going out "there" to find one.

Since I've disassembled everything on the lathe apron, could I partially mill or drill out the pin? The new pin mikes out at 0.316" on one end and 0.31375" on the other. The 0.316" section is about 0.4" long, and it appears to be the part that presses in the apron. The 0.316" end will not fit through the gear assembly, but the longer 0.31375" diameter part does.
View attachment 330642
Not sure how to center a drill, through... Not much to center on. Maybe I could eye a 0.25" end mill down the middle. Hopefully I could then drive the pin out. Or is this a bad idea?

well....not sure why I didn’t see your reply but I replied and then saw success. Good for you. And...I didn’t know you had a mill. Anyway....just ignore the rest.

A propane torch would work fine to heat up the shaft.
You just need a drill bushing. Steel is best but who knows...a wooden dowel would work in a pinch. Center drill ....Using a 1/8” drill bit a small piece of 3/8” dowel about 3/4 long . Put that in a drill and make a small taper on one end by holding a file against it. Now you have a drill bushing. Put that in the recess of the bent shaft. Looking at the picture, it looks like you have a small recess.
Now you have a drill bushing to guide your 1/8” drill bit. Get a couple of good cobalt drill bits because I’m guessing that shaft is hardened. Use oil also when drilling.
once you center drill about 1/2” in.....then go with a 1/4” drill bit. And then 5/16”. And then 11/32”
At that point it should come out.

 

[WobblyHand]

Maybe some forum time shifting / tomfoolery? I have some walnut shell media - going to blast the apron tomorrow to get it ready for paint. It's definitely looking sad after all this work (beating!) on it. From what I understand from engine work, walnut shells don't significantly affect dimensions of iron, but do remove paint. If anyone knows otherwise, please let me know soon!

 

[WobblyHand]

Walnut blasting cleaned up the apron nicely. Found a local machine shop to press in the new shaft into the apron. Supplied him a bushing to use as a backer. It was a 2" diameter disk of 1018 that I fly cut flat with my new Sherline flycutter. Came out well considering I ran it too slow on one side. Upping the RPM improved the finish a lot.

The disk was smaller than the smallest U on the shop's arbor press. That arbor press was big! The machinist reached way over his head and pulled the lever down and the pin was pushed in with no drama or effort. Best part, it was gratis! I tried to pay him, (twice) but he wouldn't take anything. He just said, see you next time...

Test assembled everything onto the lathe. Everything fit

Next week, when the paint arrives, I'll paint the apron, and do the final adjustments. Have little cork stoppers and dummy screws to plug all the holes for paint.