Making a M6-70 bushing

[topcat41468]

Instead of buying a used M6-70 gear bushing, how would I go about making one? Obviously I cant turn this down on the lathe with the integral keys.

 

[ErichKeane]

I'd do it on a rotary table on the mill. If you can turn the table on its side, it ends up being pretty easy.

 

[MrWhoopee]

Depends on what tools you have available. I'd turn the OD, rough the ID, mill slots for the keys without breaking out the ends of the bushing, make rectangular keys with a step on each end to allow the key to reach the end of the bushing when inserted in the slots, insert the keys and TIG across the ends of the key and bushing, then finish bore the ID.
Or something like that.

But then, I don't have a rotary table.

 

[ErichKeane]

Depends on what tools you have available. I'd turn the OD, rough the ID, mill slots for the keys without breaking out the ends of the bushing, make rectangular keys with a step on each end to allow the key to reach the end of the bushing when inserted in the slots, insert the keys and TIG across the ends of the key and bushing, then finish bore the ID.
Or something like that.

But then, I don't have a rotary table.

I might suggest using some sort of glue for the keys (loctite 609?) To avoid the welding, but that is a pretty good plan!

 

[topcat41468]

I have a rotary table and had been thinking like that, but I like the keyseat pocket and affix the key. Thank you.

 

[Janderso]

Man, that would be a challenge for me.
Show us your end product.

 

[wa5cab]

I would first call Clausing and check on the availability of new ones. The larger one for the 10: and 12" is but I don't recall anyone ever saying whether the one for the 6" was or wasn't.

 

[MrWhoopee]

I would first call Clausing and check on the availability of new ones. The larger one for the 10: and 12" is but I don't recall anyone ever saying whether the one for the 6" was or wasn't.

Yea, but where's the fun in that?

After thinking a little more about making one, it might be desirable to leave the keys oversize and finish after they are affixed in the bushing.

 

[topcat41468]

I think I'm going to use and end mill in the horizontal mill and put the stock in the center of my rotary table and rotate it back and forth along the height. then shift the table laterally and square the keys. I'll do it in brass or AL, as the originals were Zamak.

 

[wa5cab]

Brass or Bronze are probably better materials to use, given that the double-keyed hubs spin on the shoulder-bolts that mount them. I doubt that aluminum would last very long.

FWIW, for about the past 30 or 40 years, the factory replacements have been made from some type of black plastic.