Testing servomotors in my printer... again.

paulg4h

@mrehorstdmd Hello,
I try now to wire up a JMC iHSV57 Servo to an RRF board, maybe you are so kind and help me to wire / set it right?

this are the axis config line:
M569 P0 S0 R1 T4.0:5.0:6.0:11.0 ; physical drive 0 X goes backwards

The board is sourced with 24V, the Servo with 30V.
Wired on the Servo to the board are
ENA+ > ENA
DIR+ > DIR
PUL+ > STP
ENA- > GND
DIR- > GND
PUL- > GND

GND of the servo input is also wired to the signal GND

The servo just flashes in one second interval infinite, the JMC 1.7.6 sw is working either but I have no clue which parameter needs to be set either in the servo or RRF to make it working.

Many thank's in advance for all your support!

mrehorstdmd

@paulg4h I think your timing values look OK.

I used an expansion board for the Duet2 controller to get differential step/dir/enable signals. I believe that single ended 3.3V signals may not be enough for the input of the servomotor. I wired the expansion board Step+ to the step+ input, step- to step-, etc. and it works fine.
I think that if you're wiring it single-ended you may need a level shifter to get to 5V.

Here's the manual for the motors . Page 40-42 covers the connections for step/dir/enable. It shows switched ground, high side switched, and differential input (which I used). There are couple links to youtube videos of the parameter tuning in English a couple posts up from this one.

Take a look at this to protect your power supply and anything else connected to it: https://drmrehorst.blogspot.com/2022/05/bank-account-protection-circuit-for.html

paulg4h

@mrehorstdmd manny thank's for your reply!

I will test that within the next days and come back to you!

paulg4h

@mrehorstdmd
After adding a level shifter from 3.3 to 5V the servo now works, even when there is no GND connection between the board and servo PSU

Jay point me to your reverse protection circuit, but I am based in Austria and need to build that at my own for only my four servos which would cost the same as four 36V 154W MeanWell PSU's which I use to drive them on my KillerBee.

mrehorstdmd

@paulg4h You don't really need regulated supplies to power motors. If you use analog power supplies with plenty of capacitance you probably don't need to worry about power supplies blowing up due to transients.

The protection circuit protects anything that you might have sharing a power connection with the motor. If you don't share connections there's not much need for the protection circuit as far as I can tell.