Run a stepper from 2 DM542 drive

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Originally Posted by A_Camera

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

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I have something similar with this:
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
It is a good candidate for what I need?
Or this one is better:
https://www.amazon.co.uk/General-Pur.../B0087ZTGNNext I need to wire an on/off button. I need to have a way to change the state of the relay to use one or another sets of inputs.

Thank you
Gabi

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Originally Posted by dazp1976

Diagram looks like some kind of 4 pole contactor type where the coil activates all the contacts at once.
Positioned all 4 NO for UC300 use and NC for arduino.

I'd suggest the most used one of the 2 controls be on the NO side then power the switch to the coil to flip it NC for the other.

Step/Dir could be a problem if the logic I/O flips with contactor switch over could it not?.

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I don't know what would be the point of changing to your suggestion. The way I do it works fine. The switch is manual, has actually nothing to do with Arduino. Step/dir/en is controlled by Arduino or UCCNC, depending on the position of the switch. Why would Step/Dir be a problem...? As I said, it works and I use it.

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Originally Posted by gabi68

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.

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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 It is a low power signal relay, fast and requires very little current, but it is obsolete so maybe hard to find.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

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Originally Posted by gabi68

I have something similar with this:
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
It is a good candidate for what I need?
Or this one is better:
https://www.amazon.co.uk/General-Pur.../B0087ZTGNNext I need to wire an on/off button. I need to have a way to change the state of the relay to use one or another sets of inputs.

Thank you
Gabi

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The second link does not show me anything, but the first is OK, except that you only need four relays, so it is better to buy a 4-channel type.

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Originally Posted by A_Camera

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

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Sorry to be a pain. I have 4 inputs which need to be changed between. You said I will need Pul+, Dir+ and Ena (unconnected in my case). What should I do with the rest of the wires (Pul-, Dir- and Ena).

Thank youAttachment 30721

Use a 4 pole double throw relay. Known as 4PDT.

If you do not understand this do a google search about relay basics.

I've not really been following this thread, but the simplest option is a 4PDT relay as has been suggested, but you only need to switch the Dir+/-, and Step +/- signals.
Driver is permanently enabled, so you don't have to worry about it losing power and the Z dropping.
And the GND is only needed for the main power, as the driver inputs are optoisolated.

The only issue with using a relay is with switching such a small current, the contacts will likely oxidise with use due to lack of current to wet/clean the contacts, eventually leading to lack of continuity,
For a circuit only switching occasionally, it'll likely be a long time before failure is likely to be an issue, but it's something to bear in mind.

Yeah so basically go for a relay rather than a contactor.

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Originally Posted by m_c

I've not really been following this thread, but the simplest option is a 4PDT relay as has been suggested, but you only need to switch the Dir+/-, and Step +/- signals.
Driver is permanently enabled, so you don't have to worry about it losing power and the Z dropping.

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That is only true if he ALWAYS wants to have the stepper energised and always holding. That is not always desirable or even advised. So unless you absolutely certain that he doesn't care about enabling/disabling the driver it is indeed necessary to switch the enable signal also. Regardless of which, there is no harm in switching it, but there can be harm in not switching it.

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And the GND is only needed for the main power, as the driver inputs are optoisolated.

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GND is the same as STEP - , DIR - and EN -. It is better to connect those to the same - output as the one providing the control signals. Again, it would do no harm and we know too little about his design and implementation.

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The only issue with using a relay is with switching such a small current, the contacts will likely oxidise with use due to lack of current to wet/clean the contacts, eventually leading to lack of continuity,
For a circuit only switching occasionally, it'll likely be a long time before failure is likely to be an issue, but it's something to bear in mind.

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That's why I said that a small signal relay needs to be used, not a contactor. You talk about a contactor which is designed for high voltage and current.

Or if you want to be really simple, a 4PDT switch. Which would mean a human having to do the change over. Would do even during just testing.