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SJ781
10-30-2003, 09:48 PM
This is my first time posting to the forum but have spent a little while browsing and must say that there is a lot of usefull info here. Thanks....
I've searched the forum for cable info and did not find what I was looking for so.. here goes. I'm currently retrofitting my Jet milling machine for CNC. I have most everything to finish it but was wandering about the cable for the servos and encoders. I've searched the web for a single cable solution (per axis) and have found several cables designed for servo control. What I am looking at is 3 conductor 16AWG for the servo and 4 conductor 19AWG individually shielded for the encoder all housed in one housing shielded with copper braid. Is anyone using anything like this. Everyone I've talked to uses two cables because of interference issues. will these cables work? Any help would be appreciated.

Mariss Freimanis
10-30-2003, 10:37 PM
Try using CAT5 network cable. It's cheap, reasonably flexible and can be found almost everywhere. Being twisted-pair, it offers reasonable sheilding.

Hint: Never send two signals on a twisted-pair unless they are differential. Send a signal on one wire of the pair, ground the other wire. Otherwise the crosstalk will wreck the signals.

Mariss

balsaman
10-30-2003, 11:28 PM
Cat 5 cable isn't very flexible tho, and it had no #16 wires for the motor in it. I would go with two cables. I used shielded cables for both motor and encoder. I grounded the shields at the controller end only. All my cables are in one cat track and don't have any noise issues in the motors circiut so far.

To answer your question more directly, no I am not sure how the 2 in one cables work or where to get them.

Eric

HuFlungDung
10-31-2003, 11:42 AM
If I had a choice, I would run the encoder shielded cable in its own conduit.

Having said that, my Shadow controller cables do run all the power wires and the encoder wires in one conduit, and they do get away with it. But, shielding is of course, present on the encoder cable inside of the conduit.