Hello,
A few years back I acquired a DM4400 for an good price. However, it turned out to have bad spindle bearings and I had to do a spindle rebuild.
You can check out how I did that in this post.
I have to thank Dan ''drhanger'' for helping me with that repair! It turned out to be a lot of work and costed me a fair amount of $$$.
But after all it was fun and a great learning experience, so I am actually happy I got the chance of taking apart a spindle cartridge and making it work again.
The paint on the machine was terrible when I got it. It was starting to break off in large flakes. So I had to repaint it,
I used two part epoxy paint. (the type used on backhoes, tractors etc) I was afraid it might not hold up to the coolant,
but it shows no signs of that to this date. So far so good.
DM4400 was shipped with a SKIP controller, this controller does not take traditional G&M codes, so I knew when I bought it I was in for a rebuild.
I was thinking of what controller I could use, I had been using Mach 4 from Newfangled Solutions on a cnc bench top lathe, but I was not impressed with either the software or hardware (PoKeys57cnc)
I was thinking of going with Linux (mesa) but I am not all that good at programming (yet) so I went with the newly released (at the time) Acorn from Centroid. The acorn has preprogrammed I/O's that you assign. I am really happy with that choice.
The Acorn motion controller however could not controll the ATC or drawbar mechanism from their default settings. So I used an inexpensive PLC from Allen Bradley to controll the drawbar.
The ATC is not working on my machine, but I am not missing it for the type of work I do.