Flat 12AWG Wire Legal?

[G33K]

For various reasons I am looking into using flat 12AWG wire to drive the two motors for our shooting mechanism. I have found no rules thus far that prohibit the use of flat wire, as long as they are the appropriate gauge for the application [R44]. Additionally, the lack of color coding on the flat wire is not an issue as pointed out in [R45] because the output from the Jaguar is not necessarily constant polarity (granted we'd still mark the wires for reference).

Here's the wire I'm looking at: http://cableorganizer.com/flatwire/audio-cable.html (P/N FTW-55921201)

Is there anything I've missed that prohibits the use of flat wire? Thanks

[Team 4057]

I don't think it is, the problem is the fact it is not color coded. even if there is no set polarity I would still be wary. you are right the rules don't prohibit the use but in past competitions inspectors vary so one might pass you and later you might get dinged. So I guess it is legal but I would still check with the GDC for an official ruling

[the man]

Either way this stuff is very cool.

[Jim Wilks]

Assuming it is legal, a couple of other concerns should be noted:

1) At $2 to $3 a foot, this stuff is quite expensive.

2) If you have problems with it at competition such as open or intermittent connections, how are you going to troubleshoot it?

[CalTran]

I'd agree that the stuff is cool, and I can relate as to the uses on a competition robot, but we have had experiences where we used 18AGW wire that was white and yellow, and got rejected by an inspector. Not a huge issue, we just swapped out for red and black at the competition. If you can avoid it, I'd suggest you do simply to avoid complications in the future.

[slijin]

Originally Posted by CalTran

I'd agree that the stuff is cool, and I can relate as to the uses on a competition robot, but we have had experiences where we used 18AGW wire that was white and yellow, and got rejected by an inspector. Not a huge issue, we just swapped out for red and black at the competition. If you can avoid it, I'd suggest you do simply to avoid complications in the future.

Yellow wire is illegal per [R45].

The lack of color coding is an issue because color coding is required as per the connection it's used for, not the polarity of the power flow.

[RufflesRidge]

Originally Posted by slijin

The lack of color coding is an issue because color coding is required as per the connection it's used for, not the polarity of the power flow.

Do you have a rule to support this? Wire that can change polarity is expressly exempt from R45.

[scottydoh]

Originally Posted by RufflesRidge

Do you have a rule to support this? Wire that can change polarity is expressly exempt from R45.

True, but [R45] also says;

All active circuit wiring with a constant polarity (i.e., except for outputs of relay modules, speed controllers, or
sensor outputs) shall be color-coded as follows:

I think that little bit rules everything else out. Having been an inspector last year, we were instructed to make sure everything was color coded in a consistent manner, and we checked the path of most major wiring (speed controllers and such)

[Retired Starman]

R-45 requires color coding only on the power side of the speed controller or relay module. On the motor side of the controller, you may use whatever colors you want since power is passing in both directions. Past the controller there is no consistent + or - to deal with. Both students and inspectors often get confused about this.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

[scottydoh]

Originally Posted by Retired Starman

R-45 requires color coding only on the power side of the speed controller or relay module. On the motor side of the controller, you may use whatever colors you want since power is passing in both directions. Past the controller there is no consistent + or - to deal with. Both students and inspectors often get confused about this.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

I'm well aware of that fact sir. I miss read the OP, my bad.

[Alan Anderson]

How do you intend to connect this stuff to the speed controller and the motor?

[G33K]

Originally Posted by Alan Anderson

How do you intend to connect this stuff to the speed controller and the motor?

I think it's possible so scrape off the insulation and solder on a short length of standard 12AWG wire on each end for connections. In any case, it is unlikely that we'll be using this stuff as plans changed shortly after I posted this thread. Still a useful discussion, though, for sure.

[Al Skierkiewicz]

Sorry I didn't see this post earlier. There is nothing illegal with this wire being used on the robot. While it is not color coded and can be used on the output of controllers, there must be some marking on it indicating polarity. I am often cautious of using "audio" wire as many companies over state specifications. What may be termed #12 may in fact merely act similar to #12 in this application. Robot wire specifications are taken from the NEC handbook for open (not in conduit or confined spaces) wiring. Another thing I would consider when looking at this wire is it's survivability on a moving robot. Bends over structural metals could breakthrough the outer cover exposing the conductive material inside.

[Bryscus]

Originally Posted by jgw

Assuming it is legal, a couple of other concerns should be noted:

1) At $2 to $3 a foot, this stuff is quite expensive.

2) If you have problems with it at competition such as open or intermittent connections, how are you going to troubleshoot it?

I believe you can't even cost it by the foot unless you can BUY it by the foot. The shortest spool is 25' @ $75. You would have to cost it at $75 even if you only used 6".

- Bryce

[EricH]

Originally Posted by Bryscus

I believe you can't even cost it by the foot unless you can BUY it by the foot. The shortest spool is 25' @ $75. You would have to cost it at $75 even if you only used 6".

- Bryce

Per unit cost (per foot, per lb, per inch) is a standard cost comparison tool. Instead of saying, let's say, 25'/$75 for flat versus (making up numbers here) 100'/$50 for normal, you can just say that it's $3/foot versus $0.50/foot.

By the rules, yes, you're correct (though many places will cut bulk items for you and sell at a per-foot rate). But what you missed was the implicit cost comparison to normal wire.