Servo question

[davisgraveyard]

I have created extension cables for servos using CAT5 network cables.  I did this by combining all the red positive power wires of the servos into one wire.   But I was using 6 servos plus 1 LED so I still needed 1 CAT5 4 pair cables. 

I was wondering can I also combine the black negative power wires together too?  Then the only wire that would be individual for each servo would be the white (or yellow) pulse wire.  If I did that then I could get away with using a single cable.   But I thought there was something specific to the negative power and the servo as part of the controll?

[JonnyMac]

Red and Black are just power; the white wire signal, though, is referenced to ground.  You'll want to check for signal loses through the wire -- at some distance, the servo may not respond correctly.

[davisgraveyard]

FYI if anyone else out there is trying to do servos with CAT5 (8 pair) wire for 3-axis skulls I was able to use a single wire for the red wires of the servos and a single wire for the blacks.  The trick is that the black wire has to also be connected to the ground of the controller in order for this to work.  Let me see if I can explain this without drawing a picture

In my example I used 4 servos and a Prop2 controller.   The servos are in the skull and the Prop2 is in a separate box.  In the skull I wired the servos to short female servo extensions.   I then wired all the black cables to a single wire on the cat5 and all the red wires to a single wire on the cat5.  I wired each of the while wires to individual wires on the cat5 for a total of 6 wires used. 

I took 4 Male extensions and wired them to the Prop2 board.   I connected the Cat5 wires for each white wire.  I wired the red wire + to the positive side of a separate 12VDC 3a Power supply.   I wired the black - wire to the negative side of the power supply and also to the ground of the Prop2.  This last step is the trick to getting the servos to work yet be powered by an external power supply.   The real trick though is that we are able to use just 6 wires to run 4 servos instead of 12.