Thanks for the info.

I wish to build something like the below picture, where the 8mm motor shaft is replaced with an 8mm shank er11 collet chuck. However I'm wondering about two questions.



1) How does the shaft fix to the motor? What is involved in replacing the shaft exactly, just whack the original out with a hammer and pop the new one in with another whack?

2) Why use such a long section of shaft extending from the bottom of the motor and then support it with additional bearings? Why not mount the chuck as far into the motor body as possible and dispense with the additional bearings? Like my hacked picture below.