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I'm slowly collecting parts to convert my Sieg X2 to CNC.
I've ordered the stepper motors and controllers from Zapp, so no matching problems. The question is - is screened cable necessary to connect the motors to the controllers (4 core bipolar parallel). Working in the electronics industry, I know (a little) about noise in electronics. What I've seen on the you-tube sites, this is not used, or is it taken for granted? Has anyone got views, or experience on this?
I think the amount of current being supplied to the motors, the voltage swings and the speed of signal switching means that screened cable is not really required.
If you were to do high-frequency, low voltage signals then you would need it.
Some sites recommend it. A lot depends on the length of the cables, the motor current in use and the sensitivity of the electronics around it. For home/hobby use with <2m or cable and typically 2-4A motor current I can't see it being necessary. For longer runs/higher currents I might consider it.Quote:
Originally Posted by pequod
BTW if you do used screened cable, only ground it to the protective ground (mains earth) at one end, to avoid creating ground loops (which can be worse than no screening at all)
I asked the same quesion to Roy at DIYCNC when i collected my parts, he looked at me like I was one of the main characters from dumb and dumber.
This was from a chap that knows his stuff and he said for short lengths of cable that I would be using then no need at all.
Got to admit Roy can weigh people up well.....................Quote:
Originally Posted by HiltonSteve
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I would alllways suggest to use shielded cable for the motor phases, even though for a home/hobby setup it may not be required.
Why? becasue it is standard engineering practice to shield cables.
From my point of view, it is easier to suggest using shielded cables than spend time on the phone trying to fault find a customers application.
Thanks for the replies. I'll be running 4.2A approx 1.5 metres through 3 axis, so maybe it's not necessary. At £3 +VAT per metre, it needs more consideration, or if I can get it cheaper, maybe I might as well.
I don't have record of how many conversion we have done but it's quite a few, none have used screened cable and we have had no issues.
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As a lower cost way to shield cables you can use Knited Wire mesh wrap.
10 meters of it is about £15.
you can get it from RS.
http://uk.rs-online.com/web/search/s...duct&R=2649196
yes they do, but in reels of 50 meters.
so that will work out a lot more expensive for just a few meters of cable.
Quote:
Originally Posted by Lee Roberts