Need a source

[Brad Collette]

I've started wiring up the encoders on the mill and hit a snag.  The original wiring in the X-Axis (the one that moves) was replaced at some point.  Whoever replaced the wire did a really crappy job and I'm trying to do a slightly less crappy one.  I need a source for shielded/stranded cat5 wire.  I need at least 4 pairs (8 conductors) and only about 30'.  All the suppliers in town, if they can get it, will only sell 1000' rolls.

Anyone know a creative source?

Also, I've got a pretty good handle on the control side of the mill but the high power side still has me intimidated.  If anyone has a few hours this Saturday or Sunday and would like to help me stay alive, I'd sure appreciate it. :-)

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Brad Collette
573-427-7132

[Nathan Odle]

Brad:

You can easily get the stranded stuff by chopping up patch cables.  The best online source I've found is Monoprice.com, but locally any of the usual suspects (Best Buy, Staples, et cetera) have them.  What you *don't* want is the solid wire, which is what you'd find in premise wire meant to go into walls.  That would be the stuff at Lowes/HD and so on.

I also have a big spool of some nice stuff, if you tell me how much you need I can probably hook you up.

As for the 'high power' side, do you mean the servo drivers?  Those usually aren't dangerous per se, but all the usual disclaimers apply

[Scott.K...@gmail.com]

I think I can free up some time this weekend to call the ambulance when you electrocute yourself. I will put out some feelers with my grad students about cat5 wire as well.

Let me know when you would like to work this weekend.

[Brad Collette]

I didn't think patch cables were shielded.  I'm not sure how important that is though.  I think thirty feet would probably rewire the whole machine.

Re high power:  The original wiring took 240/3 phase.  Once in the cabinet, it split into a 3 phase 30A breaker for the spindle and single phase 20A for everything else.  I'm replacing the 3 phase side with a VFD. I've done a temporary job wiring in the VFD and I believe it's putting out 3 phase power as expected.  From the VFD (originally breaker) it runs through a series of fuses, contactors, and other protection devices before going to the spindle motor.  I have juice coming out of the VFD but not going into the motor.  Since I don't understand all the intermediate stuff, I'm lost.

On the single phase side, It runs through different transformers to get to voltage needed for the servo amps.  I've traced wires but haven't tried connecting anything yet for fear of frying something important or myself.

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Brad Collette
573-427-7132

[Brad Collette]

Awesome!  Thanks.  Best time for me would be anytime Sunday.  

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Brad Collette
573-427-7132

[Carl Campbell]

Brad I have about 24 feet of 15 conductor, Shielded, grounded, Low voltage computer cable that is stranded.  You are more then welcome to it if you like.  I scrounged it out of a serial connection to a AS400 some years back just in case I needed some good high quality cable. I work in columbia and live south of Jeff if you want to meet up to get it.  

Carl 

[Nathan Odle]

Ah - I overlooked the "sheided" part!  You can get shielded patches too, though locally I'm guessing you're not going to find much.

The switchgear for the 3 phase can look intimidating but I'm guessing it's pretty standard stuff.  Sometimes you see multiple contactors when a motor is wired for forward/reverse.  Most of the time any switches/interlocks operate on the contactors' low-voltage lines.  If you're not getting voltage to the motors, I wonder - is the contactor energizing (there should be a loud "click!")?  Also, here are some wiring diagrams from one of my favorite websites:  http://wiki.vintagemachinery.org/Motor%20Starter%20Wiring%20Diagrams.ashx

Fun stuff!

[Scott Kovaleski]

Does Sunday at 1pm work for electrocution avoidance activities?

Dr. Scott Kovaleski

Associate Professor

Electrical and Computer Engineering

University of Missouri

349 Engineering Building West

Columbia, MO 65211

P: 573-882-8377

F: 573-882-0397

[Brad Collette]

Sounds great.