Stepper Motor Wiring (Screened?)

[John S]

12 and a bit quid for 10 metres of screened MiL spec, post paid.

http://cgi.ebay.co.uk/Cable-Screened...mZ330339933966

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[irving2008]

12 and a bit quid for 10 metres of screened MiL spec, post paid.

http://cgi.ebay.co.uk/Cable-Screened...mZ330339933966

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Thats 4 cores of 7/0.2, equivalent to 24AWG/CSA0.23mm2... its good for 3.5A max in signal usage, but no more 0.6A for power transmission over any distance.

My preference would be http://cgi.ebay.co.uk/FOUR-CORE-SCRE...mZ300306498039 which has twice the rating and is £9.50 for 15m (£15 inc P&P)

If you want alternate lengths, try CSE cables they sell 7/0.2 4 core screened at 42p and 16/0.2 at 53p/m plus VAT & P&P which is £15 for 10m (16/0.2)

[John S]

Yup definitely a better choice and there may be even better, I didn't spend a lot of time looking.

[pequod]

Interesting possibilites. I wouldn't put 4.2A through 7/0.2. Even 16/0.2 is pushing it. It all depends on what temperature rise you can tolerate in the wire. I'd prefer 32/0.2 and that is the problem - with price and availability. I spotted CSE and their prices are good, but they charge £7.50 minimum delivery. With the conversion costing hundreds of pounds, is this a "ha'peth of tar"? Maybe I'll try the unscreened wire and see what happens. I can always re-wire.

[John S]

Stick a meter on the cables and you'll find you are nowhere near 4.2 amps PER CABLE

Drivers are rated per phase, not per wire.

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[pequod]

Interesting point John. I'm new to stepper motors, so don't understand this. The motor I've ordered is 2 phase, 2.73V, 4.2A, 3.2mH, wired Bipolar Parallel, Zapp SY60STH86-30. I haven't got the kit yet to measure. So does this mean I rate the cable at 2.1 A? This could be good.

[irving2008]

Interesting point John. I'm new to stepper motors, so don't understand this. The motor I've ordered is 2 phase, 2.73V, 4.2A, 3.2mH, wired Bipolar Parallel, Zapp SY60STH86-30. I haven't got the kit yet to measure. So does this mean I rate the cable at 2.1 A? This could be good.

Each pair of wires is a phase... so a 4.2A phase on bipolar means 4.2A is being carried in 2 wires. In full step mode only 2 of the 4 wires at any one time is carrying 4.2A and not 100% of the time, but the maximum current in any one wire is 4.2A.

16/0.2 is rated for 3A continuous 6A peak in conduit, at 4A you will lose about a volt across a 1.5m length.