Spining wires? cRIO mounting?
 

I am wiring our robot and i am a new wirer and i way wondering if it was legal to spin the + and - wires together to keep it neeter. I had the old wirer teach me how to wire. Is it ok to mount the cRIO on a piece of lexan that is a little bigger than 1/4 in with zip ties holding the lexan to the frame. I will mount the cRIO using the proper bolts. And what is the best way to sodder the range finder included in the KOP.

Re: Spining wires? cRIO mounting?
 

If I'm working with individual wires that I'm using to connect to power I always twist them together (I did this last year on the mini-bot wiring). Not only does it makes things look neater but it can actually reduce any electrical noise on the wires (the twists provide a kind of capacitive coupling that tends to shunt out high-frequency voltage spikes).

Helpful hint - use a drill to twist the wires together.

Re: Spining wires? cRIO mounting?
 

Trust me i do i put one end in vice put a ziptie around the vice end and then put it in a drill until it is nice and tightly spun and b4 i take it out of the drill i zip tie the drill end so it doesn't unravel and then i cut off the part that was in the drill and vice to be safe.
It is legal though right and any thoughts about the cRIO

Re: Spining wires? cRIO mounting?
 

Because there is no rule specifically prohibiting it, yes, it is legal.
<R44>:
So long as you use the appropriate wire gauge, you are in compliance with the rules.

In terms of the cRio mounting, yeah, that should be okay.

Re: Spining wires? cRIO mounting?
 

Rules 44 & 45 cover the use of wire on the robot. For example, there's this:
The branch circuit may include intermediate elements such as COTS connectors, splices, COTS flexible/rolling/sliding contacts, and COTS slip rings, as long as the entire electrical pathway is via appropriately gauged conductors.

A search of the rules reveals nothing to say that twisting the wires is illegal.

Re: Spining wires? cRIO mounting?
 

I hope you're attaching the lexan backing to the frame using something a little more robust than zip ties only. CRIOs are kinda expensive to replace.

Re: Spining wires? cRIO mounting?
 

One last thing then I'll shut up.
I've attached a presentation I give the team before build season starts. You might find it useful.
Have a great time...

Re: Spining wires? cRIO mounting?
 

Shaun,
Wire is best twisted when the ends are free. Using the drill at one end, have another student hold a wire in each hand. While you spin the drill, the other ends of the wire will also spin while the wire is being twisted. Tell your partner to let them spin in their hand and you will have a nice twist without damaging the wire.

Re: Spining wires? cRIO mounting?
 

Not only is the cRIO kinda expensive, it's a big heavy brick with a good bit of inertia and not the sort of thing you want to come loose inside your robot. It may take you hours to get everything back the way it started. Or you may never get it back the way you started...

Can I quote a rule and fail you at inspection for mounting it that way? No, not really, unless I think it is a safety hazard. Am I going to suggest strongly that you change it when I see that at inspection? Probably.

Instead of the zip ties (which really should never be used to attach anything with any significant mass to the robot) can you get a couple of bolts through the Lexan and into the frame without them touching the cRIO case? That would be your best option.

Re: Spining wires? cRIO mounting?
 

Ok so i will through bolt the lexan through the 80 20 and i dont have a partner holding the other end i put it in a vice and one done put zip ties on each end after i cut the part that was in the vice and in the drill so there is no chance for damaged wire.

Re: Spining wires? cRIO mounting?
 

The lexan which is a 1/8 th larger than 1/4 doesnt even flex when you put the crio on it and you could even put the battert on it and it gives about a 1/4 of an inch

Re: Spining wires? cRIO mounting?
 

Not worried about the Lexan breaking. Worried about the zip ties breaking when you are driving forward at 10 ft/sec and are hit head on by another 150 pound robot that is going 10 ft/sec.

Re: Spining wires? cRIO mounting?
 

150 Lb robot? How did you get that one through tech inspection ::ouch:: :)

Re: Spining wires? cRIO mounting?
 

Ok i will bolt through 80 20 on monday. Will it be a big difference if we only use 2 cims instead of 4 the for the drivetrain. Do you think that 2 cims will make our shooter recover that much faster than just using one and i know we ca only have 4a cims on our rlobit this year

Re: Spining wires? cRIO mounting?
 

120 lbs robot + battery + bumpers = 150 lbs

Re: Spining wires? cRIO mounting?
 

Shaun,
When you don't let the wire twist naturally, the strands inside tend to twist to the point of breaking and force their way to the surface of the insulation. You might get lucky and then again, you might not.

Re: Spining wires? cRIO mounting?
 

We made our electrical board out of 2 pieces of Lexan sandwiched together. We zip-tied most everything else but bolted the cRIO down. It was hard to get the zipties through the modules. :) 11 pounds when all was said and done. Note to self, replace the nuts with locking nuts tomorrow. After that, on to not making the cabling a rat's nest.

Re: Spining wires? cRIO mounting?
 

cgmv123 - Why two pieces of Lexan?

You want to make sure your cRio is mounted securely no matter what... it's expensive to replace, and a huge brick with a lot of momentum. Remember when mounting it, however, than the bolts you use to mount it to the lexan (or wood, or whatever your electrical board material is made out of) are likely to be electrically conductive as well - if those bolts them hit your frame or a bottom pan in your robot, the cRio will be grounded to the chassis (which means you'll fail inspection until you correct it). So make sure you get some good backing there or cut holes to ensure those bolts aren't touching anything metal other than the cRio!

Re: Spining wires? cRIO mounting?
 

We only had quarter-inch thick Lexan handy, so we sandwiched 2 together for extra support.

And the Lexan automatically isolates the cRIO, so we are set there as well. The Axis Camera is a different story.

Re: Spining wires? cRIO mounting?
 

What is the stroy with the axis camera i know how to wire it but mounting it? ?

Re: Spining wires? cRIO mounting?
 

The camera, like the Crio has a metal chassis that is tied to the negative lead of the battery. The camera, when used, must be insulated from the robot frame.

Re: Spining wires? cRIO mounting?
 

So you reccomend putting it on a piece of lexan

Re: Spining wires? cRIO mounting?
 

Shaun,
I understand how you want to twist those wires, and I admire your understanding that the wires could get damaged. This is good. Also, I agree with everyone who says that it is perfectly legal to twist the wires.

A better way to twist wires together is to kind-of braid them. When you just spin them with a drill, each wire twists inside itself too, and that's not as good for the wire. I know it is a little harder to twist them by hand, but it is better for the wire.

To twist wires the right way, put one end in a drill and start it spinning. Have someone else hold the single wires loose, in a "V" shape as they twist together. This YouTube video shows a guy using a machine to do this, but you can do it by hand too.

If the wires get twisted inside, which happens when you use a drill and vise, they can break inside (even in the middle of the wire) where you can't see and then you have real problems.

Re: Spining wires? cRIO mounting?
 

You can put it on anything else that won't conduct electricity. The metal case of the camera, and of the cRio, both MUST be insulated from the metal chassis of your robot. Inspectors WILL check for this and make you fix it before your robot can compete.

Lexan doesn't conduct electricity, but also wood, rubber and other things might be good choices too.

Re: Spining wires? cRIO mounting?
 

How about mounting the cRIO (to metal frame) with a rubber gasket and nylon hardware? Crazy?

Re: Spining wires? cRIO mounting?
 

Alternatively, you could use some fishing swivels and fishing line to hold the wire for you, just be sure to wear your ::safety:: in case the line decides to break.

Re: Spining wires? cRIO mounting?
 

This would work but the nylon hardware might not hold in this year's wild game.

Re: Spining wires? cRIO mounting?
 

Agreed - we mounted to lexan and lexan to the frame.

Re: Spining wires? cRIO mounting?
 

Since you are worrying about the visual appearance of the robot, I would not recommend spinning the wires. Instead, go to your local electronics store and buy wire with an outer casing. It makes everything look nice and neat, and in some stores, you have a choice of colors, so you can chose the wire to match the color of your robot. You will also have a choice of how many wires you want in the bundle, so that will eliminating having to run several strands side by side. We use these wires on our robot and they make it look great, and neat.

Re: Spining wires? cRIO mounting?
 

Mind [R44] and [R45]. Power wires for the cRIO must be 20 AWG or larger (per [R44], and the positive must be red, white, brown, or black with a stripe for the +24volt side and blue or black for the negative side.

There are no restrictions on color for wire management devices such as spiral wrap and cable carriers, however I don't know if a casing such as the one shown is in the same category. That might be one for Q&A.

Re: Spining wires? cRIO mounting?
 

An alternative to consider is getting zip cord, which is essentially two wires conjoined side-by-side, generally a red and black one.

Re: Spining wires? cRIO mounting?
 

Nathan,
The type of wire you are referring is jacketed multicore wire. It is available in shielded or unshielded, individual conductors or paired, and is generally available in small quantities up to 20 conductor. Jacketed cables are legal for use on FRC robots. You may be able to find jacketed paired cables in #12 or #10 at hifi outlets in your area as this is common for speaker interconnect.
In larger quantities (500' or more) higher conductor counts are available. The phone company uses 50 and 100 pair cables. I stock and use 26 pair and 32 pair shielded cables for microphone interconnects and analog or AES trunk wiring. Many road shows use 50 pair cables for mics, stage monitor and console interconnects.