Electrical Board Mounting

[imjessica]

Hey everyone! more pictures of circuits would be really, really helpful. The older pictures have different pd boards and batteries. If someone could also have some closeups of certain connections (like the wires connected to the pd board or the jaguar) that would be VERY helpful. I cant figure out with the outlets on the jaguar are called. thanks so much!!

[GiannaRae23]

We mounted ours on a board last year. Yes, like a wood board. No, it didn't catch on fire. Haha. We used zip ties to keep the wires organized and a label maker with a flag function to label each bunch of wires appropriately. It was a life saver when things needed changed...Also, our cRIO was held in place with velcro...that stuff is your friend. If I find any pictures of ours from last year, I'll be sure to post them. Hope this helped!

[imjessica]

Originally Posted by GiannaRae23

We mounted ours on a board last year. Yes, like a wood board. No, it didn't catch on fire. Haha. We used zip ties to keep the wires organized and a label maker with a flag function to label each bunch of wires appropriately. It was a life saver when things needed changed...Also, our cRIO was held in place with velcro...that stuff is your friend. If I find any pictures of ours from last year, I'll be sure to post them. Hope this helped!

yes that would be helpful! did you use two layers? im not sure we have the same type of board but ours in kinda thin im afraid it wont support the weight

also, did you mount the battery on the board? its super heavy I wanted to mount it on the side of our robot but im afraid thatll unbalance it

[cgmv123]

Originally Posted by imjessica

also, did you mount the battery on the board? its super heavy I wanted to mount it on the side of our robot but im afraid thatll unbalance it

Last year, our electrical board and our battery weighed about the same. Mounting one on one side and one on the other balanced things out nicely.

[Al Skierkiewicz]

Originally Posted by imjessica

I cant figure out with the outlets on the jaguar are called. thanks so much!!

Jess,
If you look close at the Jaguar in the area of the screws, you will see one side has molded into the case V+ and V- while the other side is M+ and M-. The M screws are the motor side and V screws are the side you wire to the PD.

[fovea1959]

cgmv123 (Max): I like the idea of balancing the battery on one side against the power board on the other, but did that make for a pretty long run of 6 gauge from the battery on one side to the power distribution panel on the other?

[cgmv123]

Originally Posted by fovea1959

cgmv123 (Max): I like the idea of balancing the battery on one side against the power board on the other, but did that make for a pretty long run of 6 gauge from the battery on one side to the power distribution panel on the other?

No, the standard run length worked just fine. You can see it here:



and here:



It wasn't that much of a stretch, and it worked well.

[fovea1959]

We're going to have a short/wide robot, so I'll have an extra 10" of chassis width, which is at least an extra 10" of 6 AWG from the battery on one side to the PDB on the other. Is this extra length significant? It's not optimal, but compromises must be made....

if so, trying to figure out which is worse: asymmetry, or high CG. sidepod mounted battery will end up being 12-18" from the floor. I think I can find a spot lower in the middle, but then I have all the electronics on one side, and no battery on the other to counterbalance it.

Anyone got any experience with battery up that high?

Anyone got experience with that level of asymmetry?

Short wiring runs, weight symmetry, low CG. Pick 2... perhaps only 1.

(wish I had good pics of 2612's robot from last year; they did the side mount electronics last year, and it was gorgeous)

[Al Skierkiewicz]

As a rule of thumb, #6 wire will drop 0.1 volt for every two feet of wire length at 100 amps. Stall current on a CIM motor is 133 amps. Four CIMs at near stall will drop roughly 0.4-0.5 volts every two feet. Remember that the black wire and red wire both carry that current and the total length is included in that calculation.
At 12 pounds, the battery is a good way to manipulate COG. I always recommend that teams keep the battery low, inside the robot, to help prevent tipping.
In the order of things, COG first, short wire runs second. Symmetry can be compensated in other ways. If you tip over or can't maneuver, having good electricals won't do any good.

[wireties]

Al's advice is first rate. And one should tie everything down (note my handle ;o)). The robot is a high vibration environment and you do not want the wires moving near their attachment points (or at all). When I deliver racks of equipment to the Navy, they check for wire bundles to be tied down every 6" and at every point a wire enters or exits the bundle. Plus a clean wiring effort reduces the chance that a wire gets caught in a moving mechanism.

Labels are a big help! It makes diagnosing/repair/replacing things in the pits much easier. Label the wires, the motor controllers, the spikes and other actuators.

It is a good idea to minimize the length of power wires to/from motor controllers but note that this is really an effort to minimize the total length from PD to jag/victor plus jag/victor to the motor. The jag/victor can go anywhere along that length with little penalty (length of PWM or CAN cables).

Work hard to minimize the 6 AWG wire lengths!

HTH

[NS_Radication]

My team is using industrial strength velcro and honeycomb structure plastic.

[CalTran]

Looks like this would be the thread to post this question into:
With the addition of the barrier this year, anyone have a shockmounting idea for the electronics board? We usually put the cRio on rubber material to absorb minor impacts, but this year looks like a more heavy duty mount is in order. We were thinking something like surgical tubing standoffs. Modeling it off the rubber standoffs of the pre-2011 compressor. (That big grey paperweight.)

Suggestions?

[Lightfoot26]

Not gonna lie, I wanna marry the person over at #254 who does their wiring... I have admired it for years. just sayin'

[Alan Anderson]

Originally Posted by CalTran

We usually put the cRio on rubber material to absorb minor impacts, but this year looks like a more heavy duty mount is in order.

I wouldn't worry about the cRIO. It's very rugged. I worry mostly about what's connected to the modules, and make sure everything is securely tightened down.

[apalrd]

Originally Posted by Alan Anderson

I wouldn't worry about the cRIO. It's very rugged. I worry mostly about what's connected to the modules, and make sure everything is securely tightened down.

Or the modules themselves...

In 2010, our cRio was mounted horizontally (with the modules facing the rear of the robot), and we managed to eject our whole analog module going over the bump. No damage to the cRio, but the analog module was no longer attached.

We promptly glued the modules in with silicone, and now we always secure the module clips with clear duct tape.