[ppBuilder]

Hi, see picture of NEMA 23 motor to worm spindle coupling. This would be the recommended way to do this I guess.
But that flex coupling is 1" long and for this small rotary table that means a lot of extra bulk just for that coupling. The motor will be totally enclosed inside the casing.

What I really want to do is to remove the spindle shaft (right of right bearing), drill & ream to 1/4" for the motor's D-shaft and move the motor right up to the shaft shoulder.
I know this is essentially a NO-NO, especially between rigid shafts and preloaded bearings.
Runout, and wobble will need to be extremely low for this to work reliable over time.

The work of machining these parts will be set out to a shop/factory.

Should I even try this? Will they be able to get the needed shaft bore accuracy?

[helpmeout]

This Is just a thought,but could you remake that spindle shaft but reduce the shaft that goes to the stepper the same size as the stepper shaftThen remove the shaft with the hub that is on the stepper motor and put the hub on the shaft you had remade.that would do away with the coupling.

[Jim Dawson]

A good shop can do the work for you and get it correct. But it might be expensive.