[surrfman]

At point of putting together control box and machine wiring. using igus chainflex cabling; non-shielded on the servo motor cable, with the limits circuits employing shielded cable. My chain is approximately 25 x 19 mm on the interior; everything looks comfortable inside chain. Going to use 14gauge for power to P-C 890 router; would it be prudent to spec a shielded power cable, or just plain to ensure no signals to servo motors get intimate with the AC router power stuff? Plan to ground at least one end of shields. My NEMA 23 motors and driver modules are from Keling.

Oh yeah... anyone got a favorite relay to use for router power control? What voltage actuator coil from what pins on parallel connector with Mach3 software? Going to use the Intel Atom Micro-ATX computer inside the control box; will have 5 and 12 volt if I have to use a dual relay comnfiguration to turn router on.

[RomanLini]

It sounds like you have a fairly serious machine with the servos and IGUS chains etc, my suggestion would be to foot the small extra expense and run shielded cable for everything you can. That would definitely include the servo motors cabling.

As for the router cable that can be normal cable if the rest is shielded, or you can even run shielded cabling for the router too.

I'm rather biased but I think the best way to turn your PC890 router on/off is with a SuperPID speed controller, it costs a bit more than a router on/off relay but will do that task and also give you precise speed control and allow speed control from your PC software. See here; http://www.cnczone.com/forums/diy-cn...ontroller.html

[terence]

Dont forget to only ground 1 end of the cable screen to prevent earth loops.
and use an interface chip Like ULN2001 to insulate the PC Port from the Relay coils.

[Al_The_Man]

Contrary to the previous method, There has been a move in the recent past to ground both ends of shields, I can provide a couple of references if needed.
This is done in conjunction with uni-potential bonding, which essentially means that all metallic parts of the system and machine are electrically bonded to Earth Ground this is found to be the most effective method to prevent ground loops etc.
I also use the ULN darlington series, but in itself does not isolate, just allows transitioning to another control voltage level.
If you only have a couple, then you can use a 2n7000, 5vTTL to 60v FET driver.
Al.

[eaglezsoar]

I would use a solid state relay to turn the router on or off.
A mechanical relay would arc at the contacts and IMHO would
not be a suitable solution.

[keith20mm]

Use a solid state relay to control spindle power.

Here's a setup I used on a Xylotex stepper drive:



One of my parallel port lines controls the Q1 gate. Q1 controls +5 or not to the SSR. The secondary side of SSR controls the actual spindle power.