I recently make the jump from steppers to servos on my taig mini mill. I run linuxcnc through mesa 5i25 & 7i76 cards. I had the system up and running for a total of 10 hours before I started running into issues. Now I tend to blow a DYN2 drive after a couple minutes of operation. DMM first suggested that I add additional capacitors to my system after the PSU so I did. I tested this and broke yet another DYN2 drive. Anyway, here is the schematic for the power side of my system:



I have 120 coming from the wall (through a power strip) into a 60V DC PSU. The 3 fuses that are shown are 15A slow blow fuses (digikey pn: F1776-ND). Both times I have fried a DYN2 drive, the fuse on the X axis has blown. The first time a drive was fried, it was when my mill was decelerating in the X from 300 IPM to 0. I was manually jogging (with the keyboard) the second time so it is difficult to know exactly when it happened. I do not have any of the alarm pins on the DYN2 hooked up at the moment.

System setup
Max velocity: 5 IPS (300 IPM)
Max acceleration: 20 inches per second per second
Ball Screw Pitch: 2.5mm (for maths sake, lets call it 0.1")
DYN2 drive PN: DYN2-TLAS-00
Motor PN: 57N-DHT-6ATD1

I sent the first fried DYN2 back to DMM and this was their response:

The drive you returned had two burned power transistors caused by over voltage, so we will need to invoice for the drive repair and will send a payment link now. Make sure to put the capacitors at the 60VDC power supply output to smooth and voltage fluctuations.

I added the two capacitors as they suggested and fried a second drive. At this point, I believe they are just taking guesses and hoping the problem goes away. But at $150 and 1 week lead time, I do not want to keep taking guesses. I personally don't understand how a single drive can be failing due to over voltage from the PSU since all 3 drives are connected in parallel. Does anyone here have any ideas on what I can/should test? The last kit I purchased from them (due to arrive tomorrow) includes two 48V PSUs (to get the necessary power), a new motor and a new DYN2 drive. I will have a total of 4 working drives once this package arrives (X,Y,Z & spare).

Thanks,
Travis