Shielded encoder cables

[converterking]

On this picture that Marc posted, the encoder wires appear to be twisted but not shielded. Is this correct and is this ok? download/file.php?id=2605&mode=view

[eng199]

Shielded twisted pair (STP) cable is the best option.
That system looks fairly basic without an inverter and with lots of space to route cables. In smaller or noisier cabinets, it is increasingly difficult to get by without shielding.

[cncsnw]

Yes, encoder cables should always be shielded.

I kept the original Bridgeport encoder cables.

If I recall correctly, they are shielded, but the shields are stripped back to where the cables enter the cabinet, and a green/yellow ground wire was spliced on. I am pretty sure I carried that shield-grounding wire to the DE9 connectors and soldered it to the shell.

This is not optimal, but does at least provide the benefit of the shielding for the length of cable which is outside the cabinet.

The optimal thing to do would be to run new cable (something like Helukabel #83813) all the way from the motor to the All-in-one DC, so the shielding can run all the way to the DE9. However, that would require extra time and money, and both those things are in short supply on small-machine retrofits.

Note that the cables that Bridgeport used are generally in good condition after 20+ years in service. The same cannot be said for the West Penn #3653 cable, unless it is protected in liquidtight conduit.

[converterking]

Where can you purchase Helukabel #83813 and what is the approximate cost? I saw their website but I doubt they would want to sell 25 foot.

[cncsnw]

I usually have the Helukabel #83813 in stock, at $2.00/foot.
http://www.cncsnw.com/contact.htm

[Toysrfun]

Belden has some quality shielded wire at a reasonable price. I seem to order more than I think and end up with less than I need. In a pinch I did shield my own wire on one machine I was getting excessive noise inside the cabinet. I wrapped those wires in aluminum foil and soldered a ground wire to foil and attached the wire to the case. It worked and solved the issue. I also wrapped that wire in electrical tape so the foil wasn’t exposed. Saved me time of waiting for wire to arrive.

[cncsnw]

Yes, the Belden #8304 is suitable, and appears to have more durable insulation than the West Penn #3653.

The only drawback to the Belden cable is that the black wire of each pair is just black, not striped. When terminating you need to take extra care to keep the pairs together, so you don't mix up, say, the black wire which was paired to red with the black wire which was paired to blue.

[eng199]

Centroid can also make encoder cables with Alpha 86604CY (Centroid PN 8723). This is flex rated and thicker than the West Penn 3653.
Very few twisted pair cables have a nice color code like West Penn, I don't know why.