View Full Version : Motor controllers/drivers/wire ?!?

Lee Roberts
05-08-2007, 06:24 PM
Now that i'v recently got myself some motor controllers/drivers any chance somone can me some advice on what wiring i should use to connect each component together.

I have the documents for the correct wiring sequence, i need to know what wire as a component i should be using.

Thanks In advance !

08-08-2007, 08:49 AM
as you have not given us an idea of the rating of the steppers , take this as a guide , you need to keep the wire to a size able to support the Current ( AMP) of the stepper , and also take into account the length of wire also , the longer the wire the greater the loss , so keep the diameter of the wire as large as practical , i.e that will fit the connectors etc , although for most use the majority of steppers are about 4-6A Current , so the ideal size would be say cable marked for a Current capability of 6 or 10A , these are usualy expressed as in the catalogue as Equipment wire for single cores and in sizes expressed as number of wires / dia of wire
just to make it more confusing , but as a guide if the cable is not marked in it's current capability here's a guide , it's better to go larger in size than to go smaller

Equipment wire ( single core )
24/0.2 = 6A
7 /0.2 = 12A
50 / 0.25 = 25A

for multicore cables
16 /0.2 = 12A

look at the wires coming out of the stepper for a visual guide , and look for wires around the same or larger in diameter

Lee Roberts
10-08-2007, 01:15 AM
Ok once again thanks alot basher !, could i just use standard electric cable.

Like what you get on a extension lead/cable? 13 amps ?

My motors are:
Max Rated Volts / Current/ Phase: 40vdc / 4.2amp / 2 phase

Could i use the cable that i cut off these as they come with alot and my controllers will be mounted within 2-3 foot from the machine so i will have some left over?

12-08-2007, 11:32 PM
Hi Lee

You might be better off looking for some shielded cable, if you are running limit switch wires close to your motor control cable it can sometimes cause problems,ie false limit switching when your machine is running.


Lee Roberts
12-08-2007, 11:45 PM
ok thanks for that, i'v got a question about limit switch so ill post a new topic about it.

Do you recomend any make or brand to use for wire, sounds like you may have already done this yourself ?

13-08-2007, 09:44 PM
Can't recommend any cable because I have not got that far yet :( , I have been looking but not managed to find any in small enough quantity's, might be worth looking into a group buy if there is enough of us. If I find anything I will post on here and let you know. The reason I mentioned the shielded cable is because I have read on other forums where this has been a big issue with some machines and fitting shielded cable and seperating the different cables /wires away from each other has rectified the faults.


Lee Roberts
14-08-2007, 12:23 AM
Ok tops marks for that info andy, let me know when you find somthing. i'v been thinking about my cabling on my machine i'm building, i'm a bit fussy when it comes to details and knowing everything is right, they call me a perfectionist, i call it knowing you'v done it right lol.

So anyway i'm planing on building a shelf type system for a laptop to sit on the back of my machine, with the driver cards and so on underneath all nicly out of the way mounted on somthing like you find your motherboard is mounted to in a pc system, i dont plan to use metal as the plate i was going to use plexiglass or somthing like that. A little off topic i know just thout i'd say :), what i was coming to is i'm gonna try and build a stealth like system for all the wires. Now you have told me about the problems i could find ill take that into consideration thanks mate.

24-08-2007, 05:39 PM
For motor cabling I would suggest Stuttgart Oflex cable... available from Kevin at Marchant Dice in the UK.. search ebay and you'll find their store. The cables are numbered internally, which helps a lot with wiring and are appropriately shielded.

Your talking about doing the job properly.. there's no way unsheilded extension lead cabling equates to this...

You have 2 choices with building CNC really... try and do it on the cheap.. and cut corners... which usually means poor/problematic performance or bear the pain and do it properly. 18 months ago I was where you are now.. asking same kind of questions etc... there's only one approach to take IMHO and thats do it right from the word go.. then you'll have something you can rely on.. and be proud of without any if's or buts.

It always costs more to do it twice than it would cost to do it right... a thing worth remembering ..


Lee Roberts
24-08-2007, 09:46 PM
Ok thank you, i got my rails/slides from kevin i'm looking at his listing now.