Chinese AC closed loop stepper

[Black Forest]

I am converting my Klopp universal milling machine to CNC. I ordered last Thursday a NEMA 42 AC closed loop stepper 20nM to see if the nema 42 would bolt up with no modifications to my mill. According to my measurements it should be just a swap. The mill has/had big DC Brushed servo motors on it. The motor showed up this morning Saturday. The seller has a German warehouse that is why the fast delivery. I wanted to know if the nema 42 would be a bolt up conversion or if I had to use an adapter plate before I ordered the "real" motors for it as in better quality Delta's! If the nema 42 wasn't going to be just a swap out then I might have gone with nema 34 Clearpaths with planetary gearboxes if I was going to have to make an adapter plate. I am waiting on my Centroid Acorn board to be delivered next week to actually begin with the tear down and conversion. I think tomorrow I will wire up the drive and motor and put the drive in jog mode and if all goes well I will install in on the mill and see if the motor is up to the task of moving the knee up and down without issue. If it is I might just order two more of these units for the X and Y axis.

[polaraligned]

All NEMA 42's should have the same bolt spacing. Only thing to worry about is the shaft length. Do you really need planetary gearboxes with a NEMA 34 motor? I don't know this setup but if it has a belt between the servo and ballscrew then you can increase the ratio to get more power at a bit of speed sacrifice, but not much. The Centroid AllinOne would be the best choice for a conversion that already has DC servos. At least you get feedback to the servo motor.

[Black Forest]

I didn't know the size of the DC servos. They don't call them nema 42. The factory was no help. All I did was measure the bolt spacing and find what it was, nema 42. The shaft is exactly the same length and the motor drives the ballscrew directly. Even the connector from motor shaft to ballscrew fits perfect. That part of this project is really easy! Wiring everything and setting up will be the challenge.

[RB211]

I didn't know the size of the DC servos. They don't call them nema 42. The factory was no help. All I did was measure the bolt spacing and find what it was, nema 42. The shaft is exactly the same length and the motor drives the ballscrew directly. Even the connector from motor shaft to ballscrew fits perfect. That part of this project is really easy! Wiring everything and setting up will be the challenge.

Wiring should be easy if you are also going with a new controller like an Acorn. The closed loop stepper should have its own driver that takes step/dir commands. The old controller if driving a brushed DC servo could be anything.

[Black Forest]

The Acorn showed up yesterday but I had no time to play with it. Today I got it wired up to the drive and motor. Just a bench test on my desk. Worked a treat. Maybe tomorrow I will mount the one motor I have to my mill and see how it handles everything. If it works good then I might order two more instead of going with Delta brand servos. If they will in fact work acceptably then I will have made this conversion for under €2000. Not bad in my book. I am now waiting on my DB44 breakout board connectors to arrive from Spain. My eyes and shaky hands just aren't up to the task of soldering those tiny little posts. I am sure I would end up harpooning the drive in anger trying to solder.

Totally unrelated but funny as hell. We had to put one of our horses to sleep this week. He was 35 years old and was living on borrowed time the last two years. Finally it was time for him to go. We put him down here on the farm. We had arranged pick up for him the next day. The truck shows up and the man loaded the horse into the truck. He gives me the receipt and I had him a pretty good tip. He smiles and says,"For this amount I'll take your Mother in Law too." I nearly pissed my pants laughing.