How often does your team check wires?

First off, we do not have “subteams” as other teams would. Our hours are from 3pm to 6pm. Anyone who is available works on what needs to be done. (Mechanically) After the robot is entirely built or close to done, we start electrical work. And electrical isnt with the students as it can get messy, the students just help bring the parts. Mentor plans it out.

I don’t think you understand the point of a pre-match checklist. Successful pre-match checks start long before “moments before [it’s] on the field for a match”. After post-match all of the sub-teams have had access to the robot and could have damaged a wire. There may have also been practice in between.

A great pre-match checklist takes just under 6 minutes to execute, and should always include a scan of the wiring.

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Surely Mentor doesn’t advocate messy wiring.

It is as simple as laying out the wires then bundling them properly.

Here is a snapshot of our Pit Checklist:

unnamed notice we do go through checks with all systems, including electrical.

This has driven down our failures immensely over the last two years - this and our FMEA. You can see that documentation here.4607 FMEA page

I am not sure what our turnaround time is for the robot ready, but it has hovered around 5-10 minutes.

Before every match we do a system check, we go as far as zip-tying our power pole connectors together, as well as our battery cable every time we switch batteries

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Keep in mind that “after a match” is also “before a match”.

We don’t wait until moments before the match to check wiring, we wait until we’re done with whatever other work we had to do, and are checking the robot for it’s next match. This is usually 20 minutes or so before the match.


Obviously tougher in districts, but still.

Yes, it could be tougher in districts. We played two regionals with 53 teams this year…not that much different from a division at Worlds.

The point is you check wiring before the match, as soon as you’re done working on the robot.

Many good suggestions. At the minimum visual inspection for loose wires, especially the power cables to all controllers. Check for loosened power cables on battery and to PDP and main circuit breakers and tighten them. Wires to and from Weidmuller terminsals. Stress relieve the USB and network cables, some of the connections issues are due to dangling ethernet cable, a robot coming to sudden stop could lose connection for a fraction of second and takes 15 to 20 seconds to recover.

A customized check list like @Alex_Jurek this definitely will be a big help.

Then, perhaps the mentor(s) can become involved in planning where the wiring and electrical components go earlier in the design/build process.

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Right before the beginning of each match (as in during queue), we tug the ethernet cables to make sure they’re fine. We also look for lights on the roborio/rpi ethernet ports right after powering on for the match to make sure it’s connected.

We run system checks after every match so that we can diagnose and fix issues if we have them — if we do make a change after a system check, then we run a system check again. We were able to increase the efficiency of these checks with time, taking about 2-3 minutes total.

With regards to checking wires, we tend to trust our connections as we secure them with ferrules and tons of zip ties. That being said, when we do have large gaps of time between matches then we tend to run through our electrical system — tightening screws and looking for loose ends. While looking through the electronics, we also have the builders go through the robot to make sure there aren’t any loose bolts.

That’s my two cents, so far it has worked great for us (having never disconnected from the field in all of our 58 matches).

We usually have mentor involvement with planning how wiring will be done, where things will go, etc. This year, we never got there–our long time electrical mentor retired from the team, and we didn’t get our mechanical prototyping and design done on time, and ended up changing the robot design late in build. As a result, mechanical stuff kind of dictated where electrical stuff could fit. And it isn’t pretty…there isn’t enough room for the wires to go where they need to go.

Some years wiring works out pretty easily, some years it doesn’t. This was a tough year for robot design.

So we have to check everything often, to make sure it still works.

Speaking as the head of the electrical subteam (& sole member) for my team and not having a supervising electrical mentor, I think that much of the experience of designing the boards just came from practice. By this I mean, I built up to 4 prototype electrical boards throughout the season and got the hang of how the systems connect together and how they should be placed. Then, as we were starting to finalize the design for the mechanics, I came in and pushed forward the “interests” of the electrical board placement in order to make sure that there would be room. From there, I designed in Fusion360 the electrical board (after getting the measurements for the board from the build team) — printing the design out in 1:1 A3 paper in order to physically measure features such as wire length to make sure everything fits. Here is a render of the board.

While designing the board, I kept in mind a few things that I learned from previous experience:

  1. Place high-maintenance (with many Weidmuller Connections, i.e. PCM/VRM/etc…) parts in easy-to-access locations. Low maintenance parts, such as the PDP and the motor controllers, can be of lower priority during placement.
  2. The USB & Ethernet ports on the roborio should be easily accessible
  3. Have two VRMs (not shown in the render, was added later) if you’re using other accessories such as a RPi or LEDs — have one solely for the router’s POE and black connector, and one for everything else. This was recommended by someone on CD, and it worked perfectly for us: this way, if a small wire on the LEDs shorts, the robot itself is still functional.

In addition, we have an interesting feature on the robot — which may be very specific to our robot design — where we have the electrical board sit on a hinge and come down for maintenance when necessary. The high-maintenance parts are still accessible when the robot is closed, but to reach the low-maintenance parts you need to “pop open the hood”. Here’s an image:

Hope this advice helps,
Orian Leitersdorf

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I shall get a picture of the electrical work tomorrow
Edit: got pictures.

TLDR: You fix a bent/broken intake or thrown chain “after” each match as needed. Then, you move on to the “before” each match items such as a wire check.
What I think is really meant in both cases (though please correct me if I’m wrong), is between each pair of matches. The reason this comes across as “before” is that once the drive and pit crews get used to working together, the first things done after each match are related to identifying problems experienced in the match and and correcting, or at least mitigating/limiting/working around them. This stuff is done “after” each match.
After that is dealt with, the drive team goes off to interface with the scouts and upcoming alliance partners, and the pit crew moves into the “getting ready” phase, which includes (no order implied as each team is different) all of the “every match” items like changing the battery, charging/verifying air tanks, putting the robot into starting configuration, and a general inspection of the robot as a whole. The wire check is part of the “before each match” general inspection for many teams.


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