[gamingan]

I will definitely add the limit switches and miscellaneous components. Love doing a complete CAD before building things; helps me check EVERYTHING (probably at the cost of the learning you get from failures though).

Electronics: I am going with 2 steppers simply because that was the easiest approach I imagined. Time to explore servos now then! Any servos you can recommend as a substitute for both steppers together?

Thanks for all the feedback guys. I've made one more change -- moving the rails onto the top (instead of side) of the extrusions on the Y/long axis, to help with alignment.

Theoretical question about Z-axis (I should probably post this in another category of the forum?):

If you were given only two linear bearing blocks (for the profile rail type, like Hiwin HGH-15 type) for the Z-axis, would you put them vertically on a single rail, or would you split them into one for each of two rails? I know four is ideal, but just wondering about the mechanics in this imaginary scenario that might pop up in the future when I want to maximize travel.

wizard, The variety of comments has certainly helped, thanks to all including you and Louie for contributing your own takes.

[maxspongebob]

I just finished a CNC mill conversion and I used Clearpath SD servo's by Teknic. They are a little bit more expensive than steppers, but super easy. The drivers are built into the servo so the control box can be smaller and is easier to wire.

For the Z axis, use 4 bearings. Anything less and you would probably be disappointed in the rigidity.