[Evilroot]

I noticed there was an old thread on these machines, but little in the way of actual details. A while back I came upon these machines at an auction, and immediately feel in love with them! They're unbelievably fast (1m/sec!), strong (15kg toolhead payload), and precise (60 micron x/y and 40 z).

I bought 10 in all, they came as a lot. Now I'm setting out to convert them to modern digital controls! I've looked at using Geckodrive but that's a bit pricey. Being an electrical engineer by trade I figure it should be pretty doable. I've already built controllers for other large CNC equipment but all used steppers, these machine use HUGE servomotors!



Pretty huh! This is one of the larger models at 1 x .6 x .4 meters. Like most it is a 4-axis machine with the toolhead rotating.



And from the back. These things are SERIOUSLY heavy duty, with very thick milled cast aluminum and steel frames.



And one of the linear motion systems. The technician in me is in love with these things! Aggressive stainless leadscrews, hardened tool steel linear rails with pillow block bearings . . . . they really don't make them like this any more!



Next up is figuring out the voltages and encoder protocols used!

I should also mention I have ten of these but only space for 5, so if anybody wants one of their own I'll be happy to sell some!

[NIC 77]

I wish I had two of those things. It would have saved me alot of time and expense on my current build. That's for sure.

Just out of curiosity, what's your asking price for one or two of those. You can send it to me in a PM. I'm curious to know.

You mentioned Geckos. As far as I know, those are only for brushed DC servos. Do you know at this point if they are AC or DC?

I would hope for 220V single phase AC servos, but that would make life too easy.

[Evilroot]

So did some research on the motors and control systems.

The motors themselves are rated for 75V DC and as far as I can tell are brushed (might be wrong on that). X Axis uses a 500W, Y/Z 300W, and toolhead 180W. The original controllers (which I do have!) use a 70V DC source to drive the motors. I verified this using the teaching pendant (which unfortunately I only have one of, but its pretty primitive anyways).

Despite the age of the machines and them being in storage for a while they all seem to function flawlessly! Perfectly smooth and very precise without my doing a thing to them, I guess bots this strong don't care about oil grease/etc, heh.

The encoders I was actually able to find a full datasheet for. Each has 9 wires. They are quadrature encoders with three data channels, each 300 pulses per revolution. Each channel is offset and has a common and signal pin, and the scope confirms. They also require 5v for the logic, super tiny draw. The last wire is apparently some sort of tachometer, can't see needing that.


As a test I tried running the motors at a more common 24V and it worked just fine . . . I used a spare PWM spindle control I had around. Probably not as fast but nice to know they accept a wide range!