View Full Version : spindle interferance.

18-09-2011, 12:33 PM
wired up all my limit and home switches yesterday, all working fine. machine will home out and stops on the limits. the switches are magnetic reed switches wired with 075mm two core cable. when i turn the spindle on all the limits trigger. i have tried playing with the debounce settings and it just delays the limits triggering. the spindle is wired with 1.5mm four core cy shielded cable which is all earthed out, with no resistance between shielding and earth. what can i do to sort this out. at the moment i have had to disconnect the limit switches and just use soft limits in mach but i really want hardare switches

John S
18-09-2011, 12:47 PM
Only earth your shield at one end only, control end is usually best.
Then disconnect each switch in turn to see if you have a bad one or at least identify which one is playing up.

Don't omit the estop from your test as this also uses the same circuitry.

Worst comes to worst change the reed switches for micro switches even if hanging on the end of the wires.
first thing is to find the culprit............then kill it :lol:

Web Goblin
18-09-2011, 02:46 PM
I agree with John, only ground the shielding at on end or you will create parallel ground paths. Connecting the shielding at one end will allow any interference to "drain away"


Robin Hewitt
19-09-2011, 10:54 AM
Unlikely to be electromagnetic, the inverse square law is your friend.

More likely to be vibration, can you pop a 'scope on one and see if it rattles?