Mt 3 vs backing plate ?

[jpackard56]

So, I sold my Craftsman 109 and in continued cleaning found a working Craftsman 4 jaw chuck with the 1/2 x20 threaded solid back. Would I be better off selling it too and getting one with a backing plate for my newer mini or would a Mt 3 screwed into the 1/2 x 20 be strong/rigid enough?

 

[Latinrascalrg1]

Cant you just get a new backing plate to fit your new lathe? I guess depending on how the new one is setup you might even be able to drill and tap a few extra holes into the existing backplate so it fits the current mini!

 

[RJSakowski]

A 1/2 -20 thread is not sufficient for mounting a four jaw chuck, IMO. It is niether rigid nor strong enough. Also, if you use a Morse taper, you will need a drawbar which precludes any through spindle work.

 

[jpackard56]

Cant you just get a new backing plate to fit your new lathe? I guess depending on how the new one is setup you might even be able to drill and tap a few extra holes into the existing backplate so it fits the current mini!

My thinking (which could well be wrong) was that some guys seem to be looking for these in their original configuration and maybe I would be further ahead to just sell this original 3 inch without mussing it for a collector type person and put the $$ toward a 4inch....

A 1/2 -20 thread is not sufficient for mounting a four jaw chuck, IMO. It is niether rigid nor strong enough. Also, if you use a Morse taper, you will need a drawbar which precludes any through spindle work.

The Mt3 arbor was so that I could use it right away without a whole lot of fiddling. I clearly had not thought about the draw bar issues ( I would have to make one up and yes it would preclude depth access....
See why all the experience available here is so beneficial to a newb like me !
Thanks fellas, I'm gonna noodle on this a while more and probably open the one I have up this weekend to see about making a different back or possibly getting access for mounting with what is there, although what is showing seems pretty thin...

 

[francist]

FYI - that little chuck looks like it's in really nice shape! Lots of times the 4-jaw doesn't get used as much as the 3-jaw because people find them intimidating or too much fuss. Consequently, they can stay somewhat mint if they just sat on the dark corner of the shelf. Might be a nice little chuck to keep around for smaller work.

-frank

 

[tweinke]

My thinking (which could well be wrong) was that some guys seem to be looking for these in their original configuration and maybe I would be further ahead to just sell this original 3 inch without mussing it for a collector type person and put the $$ toward a 4inch....

I think that may be the way to go.