Suitable cable chain

[chillybo]

Hi everyone,
Could anyone recommend what sort of cable chain would be suitable for my 4 x 2 foot 3 axis router that I'm building. Just need an idea what sort of width to buy and where's the best place to buy it from.
Regards Chris

[pippin88]

In my experience, wider is much easier. You can run out of room fast.

An important consideration is bend radius. You don't want too small / tight radius as it's bad for cables (radius needs to be bigger than minimum specified for all cables you use), too big and it can be a problem fitting the cable chain. Too big is most commonly a problem on the Z axis.

[Voicecoil]

I JUST managed to squeeze everything into 15 x 30, but it did require a bit of laying in to make sure stuff wasn't crossing over anywhere.

[johngoodrich]

https://www.ebay.co.uk/itm/R38-18mm-x-37mm-Black-Nylon-Flexible-CNC-Semi-Enclosed-Cable-Drag-Chain-1M-UK/163618534489
I have this on mine. I have two on each axis to get enough room and to keep signal and power wires separate. it also makes it easier to get the cables in as it opens up along its entire length

[AndyUK]

I think the advice I found was aim to fill no more than 60% - so I measured the diameter of each cable I intended to run through, and then treated them as squares to provide a safety margin (so an 8mm air pipe takes up 64mm2). Then get the total area, and divide by 0.6. That's the approximate internal cross section you want - the over estimate on the area means you'll have plenty of room for upgrades in the future.

Then I went shopping on eBay etc to look at common options and chose the bending radius to suit. Try to get the opening type so you can get the connectors through if you're using them.

[Kitwn]

Bangood has a host of sizes available up to 25 x 77mm at minimal cost. I think I got the 15 x 40 for my machine and have all the cables inc spindle power and cooling hoses in there.

https://www.banggood.com/buy/cable-chain.html

[chillybo]

Thanks Andy thats a good point. Maybe It would be better if I buy some CY cable and spindle cooling tubing (and whatever else I may need) to get an idea of the size of cable chain.

[chillybo]

With regards to CY cable. Is it best practice to buy shielded 2 core cable to keep step and direction signals apart in order to limit interference. Or do i use 4 core?
Regards Chris.

[AndyUK]

No problem - if it helps my four core CY cable (1.5mm2) is about the max you can use with the 2.2kW water cooled spindles before the GX20 plug becomes silly to solder on, and it's overkill in terms of the current capacity. I used it for both motors and spindle. That measured ~9mm Diameter. I used three 8mm external 5mm internal Polyurethane pipes (two water cooling and one air supply), and my limit switches use 3 core 0.5mm CY which is 7mm in diameter. The probe is the only other thing that goes through my chains, but I've taken the 0V from one of the limit switches.

[AndyUK]

The CY goes between the motor and the driver, carrying the A+ A- B+ B- rather than step and direction.

In the electronics cab between the breakout and the driver you want something like CAT5, keeping step + and - to a single twisted pair, and dir to another pair.

[chillybo]

Thanks Andy. So the A+ A- B+ B- is it OK to use four core to each stepper?

[AndyUK]

Thanks Andy. So the A+ A- B+ B- is it OK to use four core to each stepper?

Yep. Shielded 4 core CY for each stepper motor with the shield grounded only at the cabinet end, not connected to the motor.

[cropwell]

In my experience, wider is much easier. You can run out of room fast.

I'll drink to that !