[boss4]

I cut the center bore for the plates on a lathe. Although totally functional they are actually rather crude, the mounting holes are hand drilled. You might recognize one of them as the cast iron mounting plate from the original nema 42 stepper.

I would have used the mill to make them but by that time the z axis drive went bad and the X was loosing steps if I tried to cut anything harder than cheese.

There used to be and maybe still are (but I cant find them) off the shelf nema 34 to 42 adapters.

boss4

It looks like your timing pulley choice has worked out fine, you were lucky to get those adaptor plates, did they come from Dmm with the plates