First time wiring a robot

[Andy L]

Our team is made up of mainly seniors and sophomores. We rely on our seniors for most of the programming and wiring, so we decided to try and create a working electrical setup without them. I have been looking all day for diagrams of how to wire everything but i still haven't been able to find anything. does anyone have anything like a tutorial or wiring diagram?

EDIT: We do not have the power distribution blocks and we are only wiring CIMs and fans

[Doug G]

Andy,

Congrats to your alliance on the win this past weekend. We thought we had a chance but your alliance was just unstoppable. We've been Finalists now 3 times, Semi-Finalists twice - but still no blue banner.

Anyhow, have you seen this - maybe it's a good place to start.

Good luck and we hope to see you at Davis again next year.

[Andy L]

Sorry i forgot to say we are using 2006 hardware and do not have the power distribution blocks

[MrForbes]

In addition to the robot rules (section 8 of the FRC manual), and the diagram linked above, you should read the Tips, Guidelines, and Good Practices manual. It contains a lot of helpful information about building and wiring the robot.

There are links to all these documents here (some are links to more links)

[Al Skierkiewicz]

Andy,
Since this is not a competition bot you can take some short cuts. If you do not have a lot of weight or a need to push around a lot of weight, you can run the Chalupa motors on 30 amp breakers. All you need to do is wire the battery through a 120 amp breaker to a small fuse panel, insert the fuses for motors and the RC (or whatever controller) and use the same wiring technique from there for speed controllers and motors. A platform like this becomes a great tool for working on software and other development ideas during the off season and for demos.

[whytheheckme]

Do you have any of last year's hardware? If so, you can take a look at this:

http://www2.usfirst.org/2006comp/Dra...STRIBUTION.pdf

If you don't have the power distribution block, don't worry about it. Just tie all your grounds together at the stud.

Or, if you have a 2005 IFI breaker panel (rare), you can look at this:

http://www2.usfirst.org/2005comp/Dra...STRIBUTION.pdf

But this isn't too realistic, seeing that it looks like FIRST will never reinstate the breaker panel. So it wouldn't be good practice for your freshys to wire this up, because its a lot easier than the current system.

Just some thoughts.

Jacob

--Remeber, good posts deserve good rep!

[Andy L]

Second noobie question: ground stud, what is it? was it supplied or do i make it? how should i make it?

I know what it's for just like should i make it or do i have to buy something special.

[whytheheckme]

I've just used a little 1" 7/16 bolt/nut... This will work fine, just make sure you tape it up.

I wasn't on FIRST pre-2005, so I don't know if there is an 'official' grounding stud. Perhaps some older vets can shed some lights on this.

Jacob

[MrForbes]

a "ground stud" in these robots is not really "grounded", it is just a common negative battery connection. It can be a bolt, 1/4" would be a reasonable size (a 1/4" diameter bolt has a 7/16" hex head, some folks get confused about which size is the actual bolt size)

Put the bolt thru a piece of plastic, so you can mount it, and make sure it stays away from any other wiring or metal parts. Keep ALL wiring insulated and secured so the conductor does not contact the metal robot chassis or any other metal parts.

[whytheheckme]

Originally Posted by squirrel

1/4" would be a reasonable size (a 1/4" diameter bolt has a 7/16" hex head, some folks get confused about which size is the actual bolt size)

Thanks for the correction. I yell at kids all the time on my team for calling a 1/4" bolt a 7/16" bolt... And here, I did it, on the forum!

But yeah, the idea is that you can tie together all of your grounds in one place without using a power distribution block. Or using the chassis. This is bad.

Jacob

[Andy L]

how bad of a shock would that be if it touched the chasis

[whytheheckme]

lol. Probably none. It's just bad practice.... Your body would not be providing a path to the battery ground, so you wouldn't feel anything. Some applications actually use the casing/chassis for neutral to avoid running neutral wire everywhere. This is bad practice. Use the black wire.

Jacob

[MrForbes]

There is some danger with shorting the positive and negative power wires....lead acid batteries can explode if shorted. Also things get very hot very quickly when a battery is shorted, you could get burned trying to disconnect the battery (I saw this happen at the first regional I attended, a team had a demonstration device with a motor connected to a battery, the wires shorted and started smoking, and a student burned his hand attempting to disconnect the battery cable)

[Andy L]

since i already have this topic i'll add the question

how to wire a disable switch?

[whytheheckme]

Well, your master 120Amp breaker is required between the battery and everything else (as per the diagram). This will, in all cases, disable everything.

As far as a disable switch on your operator console, check out this diagram:

http://ifirobotics.com/docs/competit...guide-reva.pdf

DO NOT REVERSE THE PIN #S!!!!!! make sure that pin 1 is pin 1 on your connector. THATS RIGHT!!! P1 is not PIN 1... the trace with the number 1 is pin 1. I have reversed this, and it costs $150+shipping to fix.

And of course, you can always do a programmed e-stop, which only works as long as your program works (that is what you are trying to test... right?)

Jacob