SuperMax YCM-40 retrofit with Centroid Acorn?

I’m a new old guy here, looking to retrofit a recently acquired SuperMax YCM-40 with a more modern motion controller.
The YCM-40 came with an old Centroid CNC4-B24-MD3, with what I believe are NEMA 42 29 in/lb DC, SEM motors. These have 4 wires plus a ground coming from each motor, and respective connections on each axis card / board of the CNC 4. Unfortunately, someone has painted the machine, and the motor labels are gone. First question I guess is, for lack of encoders, does this mean these are stepper motors, and that the CNC4 was an open loop system?
What am I going to need for motor drivers, power supplies, etc.
Powering up the transformer in the CNC4 gives 46.6 DC volts, and each axis card has a 8amp bus fuse fed by the transformer. Would I be right in assuming that that 46.6 DC volts represents the motor voltage and that the 8amp fuses the motor amperage?
Then there’s the rotation unit count. Connecting 2 of the motor wires results in a ratcheting. One rotation results in 60 of these ratcheting steps. Does that equate to the number of stepper motor rotational steps?
I’m cherry to this CNC stuff, and would really appreciate any wisdom and experience that anyone could offer.

Ask on the Centroid user's forum. SEM motors are DC brush.

Thanks Brian. Will do.
Merry Christmas to y’all!

I don't know anything about the control, but I've had 2 YCM40s. As solid a knee mill as you can get, under 5000 pounds or so. I used coolant for a while that ate the glue holding the turcite, which eventually slipped out of one of the Y ways. By the time I noticed it, there was a good .003" ground off the casting. With nothing left to lose, I shimmed up that side, and put it back together. Damned thing held +-.0005 for another 5 years like that.

I got the thing for $900 and it is reasonably tight. I don’t believe it has a ton of hours, and I’m assuming it’s been sitting for a good while.
I’m in the process of cleaning it up and need to replace the missing lube pump, and add a VFD, as I don’t have 3 phase to my work shop.
It’s been on my agenda for some time to introduce myself to CNC, and this seemed a good opportunity to go arms deep into it.
I’m figuring, as a fall back, that if I can’t retrofit it at a reasonable cost, I can use it as a manual mill with the steppers as a 3 axis power feeds.

I put a Centroid All in one DC control on my YCM40 about 1 1/2 years ago.. Been very happy with it.

Curious what did you have for stepper motors, servos,or what? Did you retrofit them as well, or stay “open loop”, if that’s what you had to begin with?

Mine had working SEM dc servos that's why I used the All in one. I did upgrade the encoders.

4 wires only, plus ground, is an open loop system.

Current direction...

My current direction, is still in the Acorn direction aided by information and schematic integrating the Acorn with the CNC4 MICRO1 driver boards, from martyscncgarage, over on the Centroid forum.
I’ll post updates on the progress as it happens with the hope it may help or inspire others.

Marty's videos helped me in deciding to go with centroid. I really like the YCM40 for what I do and would like to get another one if I can find one at the right price. Where did you find yous?

Hi.. I retrofitted my YMC 30 taper SuperMax with the Centroid AIO. And I will say I love it. We have multiple CNC systems here.. My original YMC 30 came with an Allen Bradly Bandit controller. Very cool for an 83 machine! But it simply did not run... I was where you are now. What to upgrade into?

I know of the Acorn, but not what it can do.. yet.

Essentially, My mill has Baldor DC motors. They had the older (original) feed back loop tech w/ the Tachometer on the DC Motors. Here is some info on that tech at a high level (https://www.electronics-tutorials.ws/systems/closed-loop-system.html)

On the YMC- I have a few PDF manuals around I can also send along. PM me w/ an email.

On the Acorn and overall CNC Stepper based controls; I have read of Galil type closed steppers and do not know much- My note here is to tell you what I did above the Acorn. From this link, Acorn CNC controller, Step and Direction 4 axis CNC Control board with ethernet communication.DIY CNC kit) it seems it is an open loop system. I would suggest a closed loop where-ever possible but understand as I have CNC open and closed loop systems in my own possession. Have worked with both sides, and built into newer tech when/where I can. My upgrade was 2014... Been a few years and lots of other projects.

So... What it took to get into a closed loop Centroid system on mine:
A) the Baldor DC servo motors: the encoders and the Tachometer tech were 80's. I ripped out the tach and older encoder parts on the existing DC motors from the rear access cap. I then wired in and replaced w/ high-res incremental (it's been a long time and a lot of 'other' research... I might be a bit grey in some of this), differential quadrature output encoders from automation direct. Centroid can also sell them (or did then). It was simply a re-solder of wires onto the screw on harness connector ends. In summary, The DC motor shaft, and the encoder output all needed to be wired in to the existing harness which goes into the control box. Then in the controller box, wired in for power, etc, and a 9pin that goes onto the X Y, Z motor axis controller of the Centroid AIO. There are six axis ports. I used 3.

b) All the rest... New power supply, new AC line fuses, Terminal block inserts for all those wires. New AC contactor, a few 12VDC relays, etc.

c) Wiring it all in. The home and limit switches go into the AIO board. Same for the lubrication box. It was not hard but this is my skillset from a prior life. IMO.. Their manual is damn good. I did everything w/o a single call to Centroid. That's calibration included. So the manual is solid IMO.

Of course, there are full on AC servo upgrades from either Centroid, or other 3rd party sources, If you wanted to pursue the more expensive options.

Anyway, it was an adventure! I assume whether you are wiring in an Acorn or the AIO board, there is a lot of rip and replace to figure out.

Best,
CG

Found it on EBay. Company named Reliable Equipment LLC. Involved a bit of a ride to go get it, but for the price... Also, John was a pleasure to work with.
Reliable Equipment L.L.C. 808 Corporate Centre Dr, O'Fallon, MO 63368

I was wondering if that was the one you got I was watching that one too.