Run a stepper from 2 DM542 drive

[gabi68]

Hi all,

I need to control safely a stepper with 2 drives (cheapo DM542). I have a fiber laser which has a Z axis controlled by a board DLC2 (step and dir) thru a DM542 to a stepper. I have another device which has his own driver (also a DM542), but needs to acces the same stepper.

The process should be like this:
- start the machine with the Z axis stepper using the DLC board;
- push a button to use the other device - isolate the DLC board and the drive and let the other drive to take control;
- push another button or use the same one to be back to the normal state (at start up).

I am thinking to have a relay of some sort or a contactor which needs to be to a board for the step and dir, but this is vaguely.
What is your advice on this?

Gabi

[Snowtech]

Another option would be to use only one driver and switch the control signals (step, direction, and what else you have) between the two devices.

Jan

[gabi68]

Another option would be to use only one driver and switch the control signals (step, direction, and what else you have) between the two devices.

Jan

Can you be more specific, please?
Is there a device like that?
Should I make a board with step and direction from both motors and a switch between them for changing? .
Sorry, for the newbie questions, but I try to figure this one out by myself.

Many thanks
GAbi

[Snowtech]

Can you be more specific, please?
Is there a device like that?
Should I make a board with step and direction from both motors and a switch between them for changing? .
Sorry, for the newbie questions, but I try to figure this one out by myself.

Many thanks
GAbi

Well, if the DM542 drivers are already built into two different machines, my suggestion might be more work.

What you need to do it the way you described would be a 4p2t (4 poles, 2 throw) switch or relay.
This can switch the 4 wires of the stepper between 2 sources, but the switch has to be rated for the full current of the steppers.

Jan

[Clive S]

Well, if the DM542 drivers are already built into two different machines, my suggestion might be more work.

What you need to do it the way you described would be a 4p2t (4 poles, 2 throw) switch or relay.
This can switch the 4 wires of the stepper between 2 sources, but the switch has to be rated for the full current of the steppers.

Jan

You will have a good chance of blowing the drive if you switch if you switch it live

[gabi68]

This is what I am afraid. Blowing a driver is not that bad (they are cheap), but the board of the laser is £1000. Open to any working solution. Thank you

[Snowtech]

You will have a good chance of blowing the drive if you switch if you switch it live

Yes, i agree, thought about that only seconds after posting, but my post count is so low that every post has to be approved by a mod, so i couldnt edit it in time.
Sorry for giving bad advice :-)

Jan

[Clive S]

Yes, i agree, thought about that only seconds after posting, but my post count is so low that every post has to be approved by a mod, so i couldnt edit it in time.
Sorry for giving bad advice :-)

Jan

Your welcome, we all have to learn 👍

[A_Camera]

Skip one driver and switch the control signals step, dir, enable and gnd. This is what I am doing on my DIY lathe / 4th axis combo. I would not switch the stepper wires. Beware that if you have some interference then you might get some extra steps, so you must be careful with the wiring.

[JAZZCNC]

The only safe way is to switch the step/dir signals, you will 99% blow the drive if you swap the motor wires when the drive is powered up.