Chuck adapter/backing plate

[mmcmdl]

I think he's more concerned with spindle threads , not the hole pattern , but I'm not sure .

 

[mickri]

The hole pattern is no big deal. I think that we are getting off track here.

It would not be hard for me to make a backing plate with 1 1/2 x 8 tpi to fit on the spindle and with what I am calling the raised center that would fit in the hole on the chuck. This is probably the best solution. I do not have material on hand and would have to buy it.

The other thing that I am considering is to make what I am calling an adapter that would have internal 1 1/2 x 8 tpi to fit on the spindle and 2 3/8 x 8 tpi to fit the backing plate of the new chuck. I have material on hand that I can use to make this. The adapter would look like this.



After screwing it into the backing plate I would face it off to be exactly flush with the back of the backing plate. I would use loctite to keep the adapter to attached to the backing plate. Would this work?

 

[Mitch Alsup]

The other thing that I am considering is to make what I am calling an adapter that would have internal 1 1/2 x 8 tpi to fit on the spindle and 2 3/8 x 8 tpi to fit the backing plate of the new chuck. I have material on hand that I can use to make this. The adapter would look like this.

View attachment 307412

After screwing it into the backing plate I would face it off to be exactly flush with the back of the backing plate. I would use loctite to keep the adapter to attached to the backing plate. Would this work?

I suspect you will have 2 problems:
a) concentricity--which is not such a big problem on a 4-jaw chuck
b) strength--lathes, by their nature, apply large forces through material as they go about their work.

 

[BtoVin83]

I would be leery of two threaded connections to mount the chuck