I also want to convert my machine to mach3.
I have what I believe to be a milltronics partner 4. At least I found a photo of one and it looks like a twin to my machine,which is a rigid ram cnc knee mill. it has 70 volt servo motors with encoders. It also has southwestern industries rotary encoders on the x and y axis.
This is my first cnc machine and my first post in the cnc area. So it's going to be quite a learning experience.
Are you going to try and keep the existing servo motors and drivers. That is what I plan on doing. I think to do this I will need a DAC board or digital to analog converter. There used to be a board called a Pixie 100 or something but the company stopped manufacturing them.
And if you have heard of the Cnc Brain. if the company ever starts producing them they will have a dac board. But haven't heard much from them for a while.
So I guess i'll start asking some questions and searching thru the massive amount of info here.
Good Luck with your project