Run a stepper from 2 DM542 drive

[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.

[gabi68]

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.

Can you be more specific? A diagram will be awesome. Thank you

[gabi68]

Woa. The forum system didn't send any emails regarding a new post on my thread. Thank you everybody for your opinions. Regarding the accuracy, a step or two will not harm (this is a fiber laser not milling machine) the focus is forgiving, but a disabled driver will cause the Z axis to fall, not good.
What is the best solution for this situation? Anything already made it out there?

Thank you
Gabi

[dazp1976]

Woa. The forum system didn't send any emails regarding a new post on my thread. Thank you everybody for your opinions. Regarding the accuracy, a step or two will not harm (this is a fiber laser not milling machine) the focus is forgiving, but a disabled driver will cause the Z axis to fall, not good.
What is the best solution for this situation? Anything already made it out there?
Thank you
Gabi

A motor with a brake then?.
Engage / disengage brake as you switch?.
I'm prob clueless and talking crap though.

[A_Camera]

Can you be more specific? A diagram will be awesome. Thank you

I am sorry but I have no diagram. Anyway, it is a simple circuit with one switch and a relay which flips the step, dir, en and gnd signals, all four at the flip of the switch. The circuit is really simple.

I made a simple sketch and scanned it for clarity.



UCCNC generates the pulses if I flip the switch and select it, or the Arduino box if I select the lathe mode. The servo is a servo with integrated driver, but it could be a DM542 also, it makes no difference as long as the step, dir, en and the gnd can be used to control it. The relay in my case is one I had in my drawer, if you can't find one which switches all the four signals at once, you can use two, or even four separate relays as long as you switch all at the same time. Just connect the coils in parallel and you'll be fine. Of course, as I said before, it assumes that both controlling devices work independently and you don't need to rely on exact positions between each devices. In my case, I don't care where the motor stops, the lathe accelerates and decelerates to a speed I want it to, and if I use UCCNC then I have to zero the position for UCCNC, so the position is lost every time I flip the switch, but for me that's perfectly fine.

I don't know if you have seen this before, but I made a video about the control box. This is an early version, since then I swapped the stepper to a servo and built my lathe, which now can spin considerably faster.

[gabi68]

What kind of relay? A link, please?

[A_Camera]

What kind of relay? A link, please?

I have no link. As I said, I had it in my drawer. You have to Google.

[gabi68]

I have no link. As I said, I had it in my drawer. You have to Google.

I keep asking about the relay because DM542 has - Pul+, Pul-, Dir+, Dir-, Ena +, Ena-, Gnd and+24VDC. According to your diagram I should have a relay with 7 inputs. Where I can find something like that? Or I got this wrong....
You use Arduino for the operation you want to be executed by your lathe. I don't need this. I only need to use safely 2 stepper motors (alternatively) with a one stepper driver.

[A_Camera]

I keep asking about the relay because DM542 has - Pul+, Pul-, Dir+, Dir-, Ena +, Ena-, Gnd and+24VDC. According to your diagram I should have a relay with 7 inputs. Where I can find something like that? Or I got this wrong....
You use Arduino for the operation you want to be executed by your lathe. I don't need this. I only need to use safely 2 stepper motors (alternatively) with a one stepper driver.

No. All you need is a 4-pole relay. Pul -, Dir - and Ena - are all connected together to GND. You are controlling only Step, Dir and Ena.

I know you don't need the Arduino. The Arduino is generating the pulses I need for the lathe operation, but that's just for your information on my use. All you need is what my drawing shows, i.e. a 4 pole relay and a switch. The one I am using is DS4E-M-DC5V made by SDS. It is a low power signal relay, fast and requires very little current, but it is obsolete so maybe hard to find. Anyway, there are plenty small signal relays which can be used, and it is not critical that all the contacts are in the same casing, so you can use 4, 2 or 1 relay depending on what you find. Here is an example which works also, but you need to wire it:

https://www.amazon.se/Yizhet-kanal-r...03086861&psc=1