Rule <R50>

<R50> concerns electrical tubing and electrical tape. Does this apply only to the battery terminals, or to ALL power distrubution connections?

Section E does not mention anything about other terminals needing to be insulated, but I recommend doing so anyway. A loose screw falling onto one of your panels and shorting it out (causing your main breaker to pop) is not the way you want to end your participation in a match.

Same goes for Victors. Insulate the V± terminals, and ESPECIALLY the M± terminals, since shorting them together will blow the unit and possibly set it on fire.

Most inspectors will want any exposed electrical connections covered with tape. Anywhere that can pose a chance of the frame of the robot being energized by the electrical system.

Trust me, you want to do this regardless of what the rule say you have to do. Last year our robot was designed with a winch system to lift other robots . The way the robot ended up being designed the electronics board ended up mounted directly above the winch so that the winch cable ran up through the electronics board. While we were performing a preliminary test with may things on the electronics board and winch in prototype stages a loose end of the wire rope winch cable hung down and contacted the positive terminal of a spike relay and some of the analog input pins on the RC. This led to some lovely arcing and smoke. Thankfully neither the Spike, nor the RC were totaled (we never ended up using those analog inputs so we still don’t know if they work or not).

Moral of the story is: Insulate everything, always!

Often a better option then tape is heatshrink tubing. It is a thin walled plastic tube that comes in a variety of sizes. When exposed to heat it contracts around exposed wires and terminations forming a tight durable insulation.

It isn’t great for all terminations, but it does pretty good. It’s particularity useful for insulating the solder cups on custom made serial and gameport connectors. The best part is that, unlike tape, it won’t slowly gunk up and fall off. It also looks professional and can be used to color code wires.

I would also recommend that teams use insulated or partially insulated crimp connectors. The very small price premium you pay is more then off set in the cost of tape and time you’d spend doing it after the fact.

-Andy A.

This rule is meant to protect first the battery and associated primary wiring and second to keep robots running for an entire match. The battery is capable of extremely high currents, high enough to weld. Battery terminals should be insulated at all times, both on and off the robot. (That is why the rules “highly recommend” you replace your charger clamps with an APP 50 amp plug.) Any electrical point prior to the main breaker is unprotected and therefore can severely damage the battery and it’s wiring. Any point after the main breaker could trip the breaker if shorted during a match. Although this year’s game may not appear to have potential for a lot of robot interaction, some may occur. You are trying to protect against a wayward piece of metal (your’s or someone else’s) from contacting the wiring in your robot and tripping off your breaker. The rules do not allow you to go out on the field and reset the breaker during a match.