Re: Knee mill conversion/ controller advice please
Looks like a nice mill.
DMM servos are an excellent choice, I have installed a few of them and have been happy so far. I have 4 of the 1.8KW units on my CNC lathe, been working great for the last 2 years.
Controllers: I could write a book on this subject. But you are used to Mach3, so sticking with that would not be a horrible idea,not that I'm a fan of Mach3. The one thing I would add is a Galil motion controller, Mach3, and 4 both have a plugin for this. The reason is that it turns Mach3 into a closed loop servo system, well sort of. At least the motors are being controlled and monitored by the Galil controller and the loop is closed there, rather that just being the open loop step & direction Mach3 system. Gives you full control over the motor tuning. Galil DMC-4040 4 axis controllers are available on eBay in the US$500 - 600 range. These are real industrial motion controllers, and very easy to program using any text editor for customization if desired. (Not required when using Mach3).
Centroid is a reasonable option, as is Dynomotion Kflop/Kanalog for a closed loop system.
Jim Dawson
Sandy, Oregon, USA