Hey there! Our team is putting together some documentation surrounding wiring (it will be public eventually), but I am curious to know your horror stories with wiring, and how you fixed them! What obscure issues have you found? What tips do you have? What makes your robots more reliable? Anything is helpful, so share those weird issues!
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I have no idea if this has happened much at all but 2023 we found out one of our NEO motors was grounding our wiring to our chassis. We had to swap out the whole motor and missed pretty much all our practice matches because of it.
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Unfortunately, I don’t have a photo at the moment, but about a week ago at Battle at the Border, the CAN Bus port on our RIO literally exploded after a midfield collision in elims. My team is still trying to figure out if it can be replaced. The port exploded because our RoboRIO was only held to the frame by a single piece of velcro tape and bounced up when our robot collided (and knocked down one of the ref stands when our robot bounced nearly 2 feet in the air 
).
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Dreadbots at 2016 MSC.
And yes, the root cause was a wiring issue.
The heroic part of this story is how the team completely rebuilt their robot.
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This was our roboRIO after this season when we didn’t cover our ports and went through many off-season events…
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i have more later, but yeah, wire got crispy. Don’t cover up key electrical components, because sometimes you need to see things. We only caught this on a recent check before comp this year. The pictures above are from last week.
Also, in 2023 we had two main wire grooves, one right next to the battery and one buried between the PDH and Rio. It wasn’t fun and you couldn’t figure out any of the wiring. Make the wires visible and neat.
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In 2011 we fried a half-dozen digital sidecars across 3 events (including champs) due to RS-775 case shorts. Not a fun time. Although this is more of an electrical horror story than a wiring one.
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I could probably write 1000 words about each of these easily, but here’s a brief list of everything 1155 encountered this season (and I’m probably forgetting much more, @AngleSideAngle and @NebuDev14 could probably add some)
- Early in build season, we melted the anderson connectors between a spark max and NEO 550 due to a bad crimp.
- The same spark max later ended up on our competition robot, which caused the following issues: random CAN disconnects and signal failures, completely killed CAN functionality on 2 PDHs (still broken, we use them as test boards only now), and a bunch of other small issues. Eventually diagnosed when we opened REV hardware client and saw that we had apparently connected 30 new spark maxes with an identical CAN ID to our robot… (related post)
- REVLib race condition would cause random spark flexes to fully bug out and lock the motor upon every boot and code restart. That was a fun one to spend 10 hours diagnosing the week before our first event. Edit: not a wiring issue, but I’ll leave it.
- If you’re using the WCP CAN lever nuts, please use ferrules. We somehow didn’t know this until shockingly recently, and it makes all the difference.
- Hot glue every JST connector on your robot, no matter what. Another thing that didn’t really set in for us until shockingly recently, makes all the difference in reliability.
- The REV absolute encoder adapters and alternate encoder adapters look extremely similar-be careful.
- VRM weidmuller connections (and anything else with weidmuller connections) wear out over time, so I don’t recommend reusing them year after year. Learned this the hard way in HVR playoffs.
- Zip tie (or otherwise secure) your main battery connectors. The extra 5-10s it takes to undo isn’t worth losing a match due to an unplugged battery. Also learned this the hard way in HVR playoffs.
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As a current Dreadbot member, we still hear about this lol. IIRC, it was caused by a short to our frame from a forgotten LED wire that we had half-removed. That short someway or another set the plastic casing of the roborio on fire (we still have the burned case on display at our shop). ADDITIONALLY, it melted the tube to our pneumatics tank, which sprayed pressurized air on the fire. Overall not a fun time (though the people rewiring it got free pizza. . .)
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Very helpful thank you!
A bad soldering job once caused wires going from our battery to PDH to arc.
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This reminded me of something. I think it was 2019 at either States or Worlds, our LEDs began to smoke and catch fire during our inspection. Somehow the inspector didn’t catch it before it was put out, and we passed! It was caused by shorting again.
So be aware to everyone with cool LEDs, make sure to isolate them with electrical tape very well. One of the leading causes of failure and Inspector told me 2023 at States was due to the isolation test failing due to LEDs not being isolated
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route your wires well or mechanical will tighten them down too much and your robot will “randomly” stop functioning.
Aka: Don’t trust Mechanical
Aka: we trusted mechanical
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In one of our competitions this season, one of our SPARKMaxes stopped working, so another team came by and installed a replacement one. They somehow wired the outputs of two SPARKMaxes INTO EACH OTHER so they both got fried during our next match.
yeah that was not a good day for our wiring team
it def was not the offending team’s fault tho (we should have been more careful checking the wiring pre-match
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In our 2023 robot, there were two main problems
- Our main electrical board was covered by an aluminum sheet with ~3 inches of clearance to wire. You could only access the board from one side and the ~3 inches of clearance did NOT include the components themselves.
- Every single wire outside of the electrical board and drive train was in one cable chase. The entire super structure was on a turret and all of the wires were bundled into one cable chase that was wired through a hole in the aluminum sheet in the center of the turret.
NOTHING was labeled, working on the board was hell, and there was no way to tell which wire was which once it entered the cable chase.
btw, it was design team who gave us no room to work
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Broke the lug that connected the battery wire inputs to the PDP.
Big spark, no robot motion.
The Anderson connector and 6awg wires were all floating in the robot, and every time the battery was plugged or unplugged we’d tug on the lug connecting the PDP. Fatigued out over the course of the Regional.
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Do not tighten the main breaker bolts while the breaker is connected to a battery
Do not plug wires into the VRM while powered
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This:
We had a Spark Max held down with velcro. When it peeled up, the wires got caught in the swerve wheel and were eaten. The encoder wire also got caught, so our odometry was royally messed up:
The position was changing by around 10^{25}\space \text{m} per loop, which becomes about 1.13 \times 10^{27} \frac{\text{mi}}{\text{hr}} or 1.68 \times 10^{18}\textit{c}. We were well beyond relativistic and into breaking the laws of physics, if the odometry was to be trusted.
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