Re: Converting Mitutoyo Millstar to ???
A Dynomotion Kanalog/Kflop system will work fine with your Glentech drives & motors. And also works with your linear scales if they are quadrature output. Nothing wrong with LinuxCNC either. I'm still using the old DC drives and motors on my machine, they are working just fine.
If you want to buy Delta drives & motors, Automation Direct is a good option. https://www.automationdirect.com/selectors/sureservo2
Automation Direct also has the less expensive LS Electric line of servo motors and drives https://www.automationdirect.com/selectors/ls-servo Not all of the features of the Delta drives, but work just fine.
DMM servo drives & motors are another good option. https://store.dmm-tech.com/
All of the above have good factory support, good documentation, and easy to use setup software. You won't normally get this when buying from non-distributor sellers. I have used all of the above motors and drives in various systems and have no complaints about any of them. I have both Delta and DMM on my lathe, and I just installed a couple of LS Electric servos on another project.
As far as a quick switchover from CNC to manual on your Z axis. It's pretty hard to do with a ball screw, but with some clever engineering it might be possible. I can switch mine over in a few seconds with a lever flip and a mouse click. My machine started out life as a 2 axis CNC/manual and I added the Z axis to the quill, originally had an Anilam M controller. I went a bit different route than most folks and designed a gear system that uses the original pinion shaft. I added an air spring backlash compensator and am able to consistently hold 0.0001'' or better in the Z axis.
Jim Dawson
Sandy, Oregon, USA