Correct wire size for servo/stepper motors ? Dummy question

[the great waldo]

Hi Jazz
I got some extra covers for the electronics mounted on the servos that should keep most of the dust out, and i'm going to be ordering lapp screened cable with 0.5mm wire in it. The only thing I have to think about is wether i'm going to need all 10 outs (I don't think so ) as I think dir-pul- and maybe alm or enable 7 wires would do the job the next wire that lapp does 1s 12 core. I still have to run the power +- volts. There doesn't seem to be a ground connection on the servo so it looks like i'll have to make sure the grounding on the frame is solid.
Cheers
Andrew

[dazp1976]

Hi Jazz
I got some extra covers for the electronics mounted on the servos that should keep most of the dust out, and i'm going to be ordering lapp screened cable with 0.5mm wire in it. The only thing I have to think about is wether i'm going to need all 10 outs (I don't think so ) as I think dir-pul- and maybe alm or enable 7 wires would do the job the next wire that lapp does 1s 12 core. I still have to run the power +- volts. There doesn't seem to be a ground connection on the servo so it looks like i'll have to make sure the grounding on the frame is solid.
Cheers
Andrew

I think you're going to be putting too much money into this with cabling.
I'm with Jazz when it comes to not liking the in built units.
A good 4 core 1mm will see you right in terms of the +/- power and grounds and will have other uses if all goes wrong.
A Lapp 12 core is a waste!.
All the signals are doing is turning voltage through the cable on or off I/O. There's barely any current going through them.
Most of my stuff is either using Cat6, Cat7 (ethernet) or DB## type wiring for most signaling (5v & 24v).

If you know for sure you won't need more than 7 wires you could use a Cat6A STP (shielded twisted pair).
A good option for this use ^.
Or even a sheilded DB9. (these are commonly used with inductive switches that use more current than signals afaik).

The above will be a damn sight cheaper than the Lapp!!!!!.

[JAZZCNC]

A good 4 core 1mm will see you right in terms of the +/- power and grounds and will have other uses if all goes wrong.
A Lapp 12 core is a waste!.
All the signals are doing is turning voltage through the cable on or off I/O. There's barely any current going through them.
Most of my stuff is either using Cat6, Cat7 (ethernet) or DB## type wiring for most signaling (5v & 24v).

If you know for sure you won't need more than 7 wires you could use a Cat6A STP (shielded twisted pair).
A good option for this use ^.

This has got nothing to do with current and everything to do with Signal and cable quality.

Cat5,6 or 7 is completely the wrong cable for this application and will cause him nothing but trouble in time. Ethernet cable is not designed to constantly move inside cables chains and over time it will break. It's fine in the control cabinet or if fixed to the machine but BAD for moving axis and cables.

Andrew:
The I/O cables are low voltage/current so don't need to be high current cables but they DO need to be flexible and screened well, this is why you need a quality cable rather than a stiff brittle cable which is what Cat5 type cable is and don't let anyone tell you differently because it will fail in time on an application like this.

Also, servo drives are far less forgiving than Stepper drives when it comes to stray voltages and electrical noise, the slightest bit of noise will make them twitch and because you plan on using the AXBB-E that doesn't offer differential output signals and the fact you will have very long I/O signal cables makes you wide open to cross signal contamination. Again this is why you need to use quality cable and with good grounding.

If your wire runs are very long I would consider using a differential line driver module to help boost and keep the signals clean.

Lastly and I don't think you mean to do this but I'll mention it just in case because you mention 12 core cables!
Don't run high power cables down the same cable as I/O, use a separate cable for the power.

There doesn't seem to be a ground connection on the servo so it looks like i'll have to make sure the grounding on the frame is solid.
Cheers
Andrew

I wasn't referring to power grounding, I was meaning good grounding practises ie: Star grounding and sending the shields to the ground point.

[dazp1976]

This has got nothing to do with current and everything to do with Signal and cable quality.

Cat5,6 or 7 is completely the wrong cable for this application and will cause him nothing but trouble in time. Ethernet cable is not designed to constantly move inside cables chains and over time it will break. It's fine in the control cabinet or if fixed to the machine but BAD for moving axis and cables.
Andrew:

Forgot about the chains.
My Cat7 (solid) go from rj45 modules 'attached' to box + machine, then connect to stranded (24awg) from there to equipment. You can get stranded Cat6A but I do use standard wire goimg from the cat7 to the various sensors etc.

However. I forgot about Igus.....

Chainflex CF10
(8x0.25)C (8core) For control. 0.25mm
(3G1.0)C (3core) For power transmission. Or (4G1.0)C (4core).
https://www.igus.co.uk/product/1015?artNr=CF10.10.04
https://www.igus.co.uk/product/1015?artNr=CF10.10.03
https://www.igus.co.uk/product/1015?artNr=CF10.02.08

I doubt their quality will be disputed (at a price).

I was trying to give you cheaper options because you may yet end up ditching these built ins after a bit but.....
If you're going to do it properly I'd suggest you go to Igus. They have loads of different options.

https://www.igus.co.uk/chainflex/unharnessed-cable
https://www.igus.co.uk/

[the great waldo]

Hi Jazz
Thanks for the input. I will be running extra cable for the power lines and will keep them as far away as possible from the signal lines. I'll be using Ölflex screened cable from lapp. I'll be using plug connectors (Locking) up to the machine and then from the boxes with the connectors hard wired to the motor drivers to minimize the chance of things shaking loose. I'm not really sure if the Alarm connections and the enable connections are required/neccessary. The machine is going to be for home use and not industrial but I would like to make everything as well as is possible even if it costs more (I've got a box full of screwdrivers that were cheap and only usefull for stirring paint, some of them couldn't even get the lid off the paint can!! ) But my trusty old red handled stanley screwdrivers I bought 40 years ago still work fine. Cable lenghts are not going to be very long as the control box will only be a few feet away from the machine (not much room in the home workshop) I'll have a bus bafor the earth in the control box to run all the earths to and leave the machine end of the screened cables screen open (Just earthed at the control box to cut down on earth loops)
Cheers
Andrew

[JAZZCNC]

You only really need the alarm signals if you are using slaved motors, in which case it would be silly not to use them if you have them.

[the great waldo]

Ok Thanks Dean
It'll cut down on uneeded wiring.
Cheers
Andrew