Cnc wiring!

**Cobey3289** · 25-01-2018

Hi guys,
Need some help, the size of wire required for cnc is confusing me!
I am going to be running nema 23's 425oz drawing 3amps. However, I am undecided as to whether to use individual wires so I can match up the motor colours all the way through to the drivers. Or, use a 4 core wire to the control box and individual wires within.
So my question is what size wire do I require? I can find suitable rated amp wire but I then get confused with the 0.5,0.75, 1.0 etc.
I have read different things about wire size in respect of using 18awg or 22awg, but most listings for wire I have seen refer to the 0.5 etc.
Is automotive wire ok?
I know I will be using proper rated cable for the actual power supply. I just need to sort out motors and peripherals.
Thanks in advance
Mick

**Desertboy** · 25-01-2018

0.75mm 4 core CY cable, you need CY normal 4 core is a big No due to interference. Wire colour is irrelevant and you'll find CY you get 3 blacks wires and an earth. It's very easy to work the wiring out it doesn;t matter how you wire it to the motor the end you wire to the drivers twist 2 wires and try to turn you ballscrew if you feel resistence you have matched pair if not try a different combination. When you have a matched pair the other pair must be matched wire them to the drivers. If the motors go the worng way invert the pin in Mach3/linuxcnc.

https://www.ebay.co.uk/itm/ALL-CY-CA...EdeT991FfFPUNw

Search for companies local to you it's not hard to source cheaper than this.

**Neale** · 25-01-2018

The CY cable I have used has the three black cores numbered along their length so you can identify which core is which at both ends. The third core could be used for an earth but it works fine as one of the four connections for the steppers - electricity doesn't care what colour wire it runs in!

Talking about awg and oz-in motors suggests that you have been looking at US sites. Europe and European suppliers tend to talk about cross-sectional area (0.75, etc) and Nm. It doesn't really matter which system you use but that's why some people use one set of units and some another.

**Cobey3289** · 25-01-2018

Thanks guys, it seems to make a bit more sense.
In my research, I've just watched a video of a guy wiring his steppers with
Cy cable. He used a 4 core plus earth and didn't use the earth. He did however expose the wires in his control box and connected them to the side of the metal box to earth them. I'm planning on building a Perspex box, so do I still need to earth the cable or can I just use the 3core and earth as my 4 wires?
Thanks
Mick

**Clive S** · 25-01-2018

Originally Posted by Cobey3289

Thanks guys, it seems to make a bit more sense.
In my research, I've just watched a video of a guy wiring his steppers with
Cy cable. He used a 4 core plus earth and didn't use the earth. He did however expose the wires in his control box and connected them to the side of the metal box to earth them. I'm planning on building a Perspex box, so do I still need to earth the cable or can I just use the 3core and earth as my 4 wires?
Thanks
Mick

You need 4 cores to connect the motor to the driver in the control box and use use the screen to connect to the ground star point. Also a plastic box is not suitable it is better with a metal box that can be earthed as it will help with the screening.

You will also need CY cable for the spindle