Use 2 drivers for 1 stepper motor

fma · 25 Jan 2021, 21:09

I would like to drive some old Nema 34 motors which need 6A/ph with TB6600 drivers, only able to output 3.5A.

Do you think it is possible to use 2 drivers to power up 1 stepper motor? These motors have 8 wires, so I can wire each half-phase with 1 driver.

Can it work? Or is it a totally stupid idea? Can I burn the drivers, or the motor, if things go wrong (bad sync)?

Thanks,

dc42 · 25 Jan 2021, 21:45

The only way to use two stepper drivers to drive a single motor would be to have them drive one phase each. Even then, you wouldn't be able to get anything like twice the motor current.

Veti · 26 Jan 2021, 05:40

the duet 3 is able to drive those directly.

fma · 26 Jan 2021, 06:44

@dc42, you are right, the current will remain the same! this is a stupid idea...
@Veti, if I apply the rule 85% of peak current, I need more than 5A...

Veti · 26 Jan 2021, 07:03

@fma said in Use 2 drivers for 1 stepper motor:

@Veti, if I apply the rule 85% of peak current, I need more than 5A...

see
https://duet3d.dozuki.com/Wiki/Duet_3_Mainboard_6HC_Hardware_Overview

Stepper driver features Up to 6.3A peak current, microstep interpolation from any setting to x256, stall detection, stealthChop2

fma · 26 Jan 2021, 07:46

I was told to apply 85% of peak current as RMS current... Or did I miss something?

Veti · 26 Jan 2021, 07:56

@fma said in Use 2 drivers for 1 stepper motor:

I was told to apply 85% of peak current as RMS current... Or did I miss something?

https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

Plan to run each stepper motor at between 50% and 85% of its rated current.

fcwilt · 26 Jan 2021, 07:57

@fma said in Use 2 drivers for 1 stepper motor:

I would like to drive some old Nema 34 motors which need 6A/ph with TB6600 drivers, only able to output 3.5A.

Why would you pick TB6600?

Frederick

fma · 26 Jan 2021, 08:03

Because I have some. I'm working on an old XYZ table which was given to our hackerspace, and we want to turn in into a CNC. Before putting 200€ in a Duet3, I would like to test it and see if all works fine.

o_lampe · 26 Jan 2021, 08:11

@dc42 said in Use 2 drivers for 1 stepper motor:

The only way to use two stepper drivers to drive a single motor would be to have them drive one phase each. Even then, you wouldn't be able to get anything like twice the motor current.

@fma
I've seen 8-wire steppers, with 2 coils per phase. If you happen to have one of those, you should be able to drive it with two drivers.

fma · 26 Jan 2021, 08:24

@o_lampe said in Use 2 drivers for 1 stepper motor:

@fma
I've seen 8-wire steppers, with 2 coils per phase. If you happen to have one of those, you should be able to drive it with two drivers.

Yes, that's the motors I have. It is possible to wire them in series or in parallels.

But even in that case, each coil will only receive 3.5A from the TB6600s, as if they were in series... The current won't be higher.

o_lampe · 26 Jan 2021, 08:38

@fma said in Use 2 drivers for 1 stepper motor:

Yes, that's the motors I have. It is possible to wire them in series or in parallels.

I'd wire them independently. Coils A+B to one driver, Coils A' + B' to the other. ( enable, direction, and steps should be parallel) That way you'd have twice the current, right?

PS: did you ask that question in the robotshop forum too?

fma · 26 Jan 2021, 09:56

No, the current will be the same as if the coils are wired in serial... I'm still about half the needed current.

Dazp1976 · 12 Dec 2021, 10:09

@fma
Seriously trying to use that to drive a nema34!!!!.
Right. You need a DM860T type driver (110vdc) and 80vdc minimum power supply size for proper good use of it.

If you're not going to do it properly or can't do the math. I suggest you find a new hobby.