Dyna Myte DM2800 Restoration Part #005

48 VDC Power Supply and DC Motor Drive

This week I verified the voltage coming out of the stepper power supply then went on to hook the G251x stepper drive power wires up. Also added the current programming resistors and dove deep into the theory of operation on the rest of the electrical panel.

I’m calling out for any info that can be found on the electro-craft brushless spindle drive. The only markings on it are AW0016-6423 Rev B. If you have anything it would be most appreciated.


  1. I’ve been in the process of rebuilding a DM3000-E lathe that I got last fall, and it has the same motor and amplifier… it’s an Electro-Craft BRU-50, but the amp isn’t complete. It looks like they removed the control board for positioning, since it only needs to spin. The I/O pins on the full amp normally go into that board, so the pinout in the manual doesn’t help, and I have yet to find a complete schematic of the amp. I pulled all of that out, though, and am using a 2.5hp brushed DC motor from a treadmill with an AMC analog amp (with tachometer feedback), but am, at some point, going to take a stab at figuring out which pin is which, since that 1hp motor is perfect for a tool post grinder I built.

    1. Yes, those are the same problems I ran into. I put about 6 months into figuring it all out then finally caved in and took it out. Of course, several months later I’m still fooling around with the servo replacement motor. If you have any luck let me know!

  2. Hi Pete,

    Nice work on the dm2800 conversion! I subscribed to your YouTube channel last night. Do you have any spare parts including the old spindle motor that you would like to sell?

  3. Do you know of anyone that has successfully done a retrofit using the ac servos that were used on later dyna mechtronics machines?

    I just got a dm4400m with Mitsubishi controls and ac servos. I’m not completely opposed to replacing motors but would reuse these if I could find recent drivers for them.

    Thank you

    1. Hi Duke,
      No, I don’t. The only place I know of where you may find somebody is over on the CNC Zone forums. I’ve never seen one of those larger machines in person, just pictures on the internet. Sorry I can’t be of help


Leave a Reply to David Harris Cancel reply

Your email address will not be published. Required fields are marked *