Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kolias on February 04, 2011, 11:59:53 PM

Title: Motors Wiring
Post by: kolias on February 04, 2011, 11:59:53 PM
The X and Z axes motor wiring are too sort on my new CNC router machine and I would like to extended them by about 4-5 feet. Instead of unsoldering the XLR connectors I was thinking to cut the cable on each and solder a new piece between the two ends. I will put heat shrink sleeves on each wire plus tape. I will also solder the shield

Is this ok or I'm looking for trouble?

Title: Re: Motors Wiring
Post by: Overloaded on February 05, 2011, 12:45:22 AM
Do a good job, use the proper gauge wire and you should be good to go.
Them little electrons won't know the difference.
 :)
Title: Re: Motors Wiring
Post by: Tweakie.CNC on February 05, 2011, 03:19:28 AM
As Russ has said make a good job of it otherwise it may let you down.

In the UK, and the rest of Europe now we have hazardous material regulations which prohibit the use of lead in solder. The lead-free stuff, unless you are extremely expert, produces real poor results which is probably why tin/lead solder is still allowed for military and other important equipment.
The tip here for anybody wanting good, reliable soldered joints is make it a military job.  ;)

Tweakie.
Title: Re: Motors Wiring
Post by: kolias on February 05, 2011, 07:37:45 AM
Nice to know and thanks both

No problem dong a good job soldering, that I know it well
Title: Re: Motors Wiring
Post by: Overloaded on February 05, 2011, 08:03:06 AM

The tip here for anybody wanting good, reliable soldered joints is make it a military job.  ;)

Tweakie.

 ;D :D ;D :)
Russ
Title: Re: Motors Wiring
Post by: Sage on February 05, 2011, 05:44:53 PM
All good answers but don't go overboard adding wire. Unless you are using really big wire you will loose power to the motors.
 
Assume 1ohm of cable (round trip out to and back from motor)
Assume a Gecko trying to drive 7A to the motor.
loss in cable = I squared x R
7 squared is 49,  x 1ohm is 49 watts lost in the cable !!!

Is moving the controller (drivers) closer to the router gantry a possibility?



Sage
Title: Re: Motors Wiring
Post by: rcaffin on February 05, 2011, 06:27:57 PM
All good answers but don't go overboard adding wire. Unless you are using really big wire you will loose power to the motors.
Assume 1ohm of cable (round trip out to and back from motor)

That's rather fine wire to get 1 ohm! If you use wire a little bit thicker than the wires going into the motor itself you should be fairly good, and a long way below 1 ohm too.
Rule of thumb: the longer the extension, the thicker the wires.
Oh yes - make it a military job and use tin/lead solder. It's still available - collect some!

Cheers
Roger
Title: Re: Motors Wiring
Post by: Sage on February 05, 2011, 07:05:06 PM
Yes, on second thought I guess your probably right.
(#14 being 2.5 ohms per 1000ft one way).
I had it in my mind that wire resistance was worse than that even in the "larger" gauges.
Even so a 20ft extension of #14 would add 0.1ohm which is a power loss of 5% with a 2ohm motor load (.1/2)
No big deal I guess.

Sorry about that  :-[

Sage

Title: Re: Motors Wiring
Post by: kolias on February 05, 2011, 07:16:08 PM
Job is done and noticed no power loss

The controller was too close to the machine to allow for maintenance and had to move it away by about 4 feet