Prepping/pressing new carriage hand wheel and shaft

[Ben1272]

Hello,

I have a 9a with a sloppy carriage hand wheel.

Some of the slop, the backlash portion of it, I was able to significantly reduce by drilling/tapping and reversing my rack. The remainder of the slop comes from a poorly fitting shaft through through the apron, and a poorly fitted handwheel on the shaft. Both have been worn in and in need of some repair.

My current thinking is to ream up the apron bore and hand wheel bore to next closest readily available ream. Then, cut the portion of the shaft that passes through apron and hand wheel off and replace with a press fit new length of shaft to match the reamed apron and hand wheel.

Other than the suggestion to leave it as is and just make chips, I would love to hear of any other suggestions for how best to attempt this lathe improvement.

Thanks in advance!!

-Ben

 

[Ben1272]

As a bit more information, i do have a small Clausing mini-mill that I could use, but I am no expert machinist. Setting up and holding the work is the most challenging thing for me to get right and my fixture collection is small.

I was hoping that I might be able to pull a ream through the carriage hand wheel bore? Is there a better way? Is the apron pretty easy to set up on a mill (i.e. is there a nice flat surface to lay it on? I have not looked yet, but before I went too far, I wanted some expert input! The more specific the details the better for me, as I said, I am no expert machinist!

Thanks again!

 

[animal12]

You could bore & bush the apron & bore & bush the hand wheel too .
animal

 

[Erich]

Worn holes and shafts are never round. A reamer will "follow" the egg shaped hole and the center will end up who knows where. Now your gears will no longer have correct center distance. I would put the apron on the mill. Indicate the hole using the unworn part of the hole. Bore it open using a boring head. Press in a bushing. Or just use it until you find you can't stand it.

 

[kitno455]

I would not use a reamer for the reasons Erich mentioned. But, I also would not indicate off the existing holes or add bushings. This is due to worn gears and shafts.

I have a 10L which had a completely trashed apron. Every bore was oversized and oblong, all shafts were undersized and scored, and all gears were worn. I mapped out the backlash of each part, and relocated every hole to minimize backlash. I used the boring head on the milling machine to open each hole to clean, straight and round. I then remade all the shafts from oversized material to match the new bores. The only bushing I installed was for the clutch, because I turned it undersized instead of making a new one.

 

[jmm03]

Kitno, what did you use as a datum point to machine the holes ? Thanks, Jim

 

[kitno455]

The compound gear at the top of the apron that engages with the cross slide. That shaft is fixed in the apron, and the gear turns on it. So, no wear in that bore. Now, I did end up boring that hole oversized because I made a larger shaft because of gear wear.