Should I replace our power distribution panel and Roborio?

We’ve just wrapped our fourth FRC season, and our Power Distribution Panel is starting to wear out–wires don’t seat properly, the plastic around where you insert a wago tool is looking chewed up and worn out, and I think I can see bits of metal shavings/wire in some of the breaker holes. The small white push connectors are similarly worn out and we’ve had a lot of electrical problems this year.

Is it possible to take it apart and meticulously clean it, or should I replace it altogether? I’m not sure how long these PDPs are meant to last. I can tell you that they’ve suffered a lot of unnecessary abuse.

PWM cables, and most other cables for that matter, on our RoboRIO come loose easily. We could never get the cameras to connect properly during sandstorms this past season, despite replacing cameras and updating software. Would a whole new RoboRIO solve these and future problems? It too as suffered a lot of abuse. How long are they meant to last? If I buy a replacement now, how likely is FRC to do away with them next year?

One thing you may want to do is use your FIRST Choice points and AndyMark voucher (if you opt out of getting the KOP frame) to offset the costs of those items. We get a new PDB, VRM & PCM every year from FIRST Choice. This year we used the voucher to purchase a new roborio when everything was 10% off at AndyMark.

The roborio is here to stay at least until 2021 and same with the PDB, VRM & PCM, see below -


A new PDP through FirstChoice is a great idea.

Find the money to buy a new RoboRio, also.

Keep the old parts to use for prototyping, programming development, etc.

We have three sets of electronics now, and use them all during build season, for prototyping and programming, and also so we can have a practice robot, and a programming robot available while building the “real” robot. With bag day going away, we will probably still need to use all 3 systems.

That’s good information, thanks!

The voucher covered the full cost of the roborio?

If you opt out of the KOP fram kit, you just use wheels, belts, and metal from past years’ robots? How do put that into the Bill of Materials worksheet?

The voucher is for $450 towards anything at AndyMark. However, if you use the KOP frame every year, it’s a better value to get that drive system kit and find another way to pay for an additional Roborio. The drive system kit alone is $650.

Assuming next year’s rules are the same, if the KOP drive system is identical then you won’t have to include it on the BOM. Just remember if you modified components of it this year, you can’t re-use it next year. Some teams just purchase a new frame and re-use gearboxes and other items.

When you say “Just remember if you modified components of it this year, you can’t re-use it next year” Do you mean that if we cut the metal to make the long chassis configuration we can’t use those parts we cut in any way next year in our robot’s frame?

I understand that everyone has to build a new robot from the ground up, but I’m wondering if it’s ok that we’ve fully disassembled all of the robots from the past four years, can we assemble a new chassis from that heap of parts?

I appreciate the help.

If you use last year’s cut as the end of the part, then no, you can’t use it. But if you cut it shorter at both ends, or leave the factory cut at one end, and cut the other previously cut end again to make the piece shorter, and there are no holes that you drilled before kickoff, etc, then you can use it.

The idea is that you don’t use anything this year that is an “old” modification to the part.

At least, that’s how I see it. I could be wrong, hopefully someone will offer a different view if so.

Your example is correct - the frame is no longer considered to be COTS once you cut the frame rails and cannot be used in a future season. The game manual defines COTS as - A COTS item must be a standard (i.e. not custom order) part commonly available from a VENDOR for all teams for purchase. To be a COTS item, the COMPONENT or MECHANISM must be in an unaltered, unmodified state

A lot of teams will re-use gearboxes, but you need to break them down to their COTS state first which is usually un-assembled.

I highly recommend re-reading section 10 of the game manual - robot construction rules - which spells all of this out in greater detail.

as a note, using the voucher like this negatively impacts your BOM cost because the VRM / PDP / RoboRIO / PCM are all 0 BOM cost items, so you’re 0ing out already 0’d items, instead of using it to offset the cost of a limelight for example.

Yeah… that’s only a problem for like 1% of teams maybe though :slight_smile:


First, on-topic, yes, please get a second control system. Using the old one again is asking for Mystery Electrical Gremlins to appear at the worst moment at competition. But don’t throw the old one away! Keeping at least one functional bot available at all times is a game-changer for coding/practice/testing.

For the frame… the absolute strictest interpretation is that you can’t use pieces that were modified the previous year, full stop.

Given your apparent budget constrains, I think you can meet the spirit of the rules by fully disassembling the chassis and modifying it for the new game.

If your students still end up leaving some parts as-is and can explain why they did that without resorting to “it was that way last year”, I don’t think any reasonable inspector will try to fail you for reused parts.

The rule is designed to prevent assemblies from being reused by students who don’t understand them. If your students own your design & modifications, I think the inspectors will have no reason to care whether you modified the AM14U3 from last year or bought a new one to modify.

Asking for community input here - do you agree/disagree with my “spirit of the rules” interpretation? Do you agree/disagree with explaining the risk to the team and recommending taking it? It definitely relies on the “human element” of the inspection process, which varies between regions - paging @geetwo since OP is from Luisiana

If you want to have fun with compliance for compliance sake… If you need a hole from last year, run a file or a drill bit through it and shave a few thousandths off. Boom, modified material is gone. :wink:

Your example is correct - the frame is no longer considered to be COTS once you cut the frame rails and cannot be used in a future season. The game manual defines COTS as - A COTS item must be a standard (i.e. not custom order) part commonly available from a VENDOR for all teams for purchase. To be a COTS item, the COMPONENT or MECHANISM must be in an unaltered, unmodified state

I don’t think that’s quite right. The blue box toward the end of section 10.1 talks about things that are neither COTS nor FABRICATED ITEMS and focused on whether changes were “made to advance the part towards its final form on the ROBOT.” If last year’s robot has a 3’ piece of extrusion and you need a 2’ piece of the same extrusion, there really shouldn’t be any problem in pulling the 3’ piece off and cutting it down to 2’.

You also should contact NI - the phone number to use is on the AndyMark roborio page and call after 2PM eastern.
Explain your roborio issues and ask for an RMA for a replacement.
Nothing ventured, nothing gained and I’ve gotten robrios replaced that I’m pretty certain were over 3 years old


The fabrication schedule is on the honor system; unless something distinctive jumps out as having been on the robot the previous year (e.g. if I saw the Space Pirate’s CARGO boiler on next year’s robot), the team compliance statement at the bottom of the inspection checklist is the only place this is likely to be caught.

That said, I agree with your quote from @MrForbes. As far as enlargening a hole - if this is a second circular enlargening of a COTS hole, no problem, as the piece would be the same as if you had drilled the larger hole this year, with no extra effort. If this is a hole that your team drilled last year into a previously solid piece of metal, then the placement of that hole was done non-COTS and pre-game-release, and this would violate my understanding of R15.


That’s true I suppose. It’d be the functional equivalent as buying new and cutting down to size. And honestly nobody is going to know or care if you reuse a kit frame that has been cut or drilled into during a previous year. Save that money however you can. But at least disassemble and reassemble, and teach some of your new students the in’s and out’s of the kit drive.

The original post also expressed concern about cable retention at the roboRio.
I can see where the retention at the CAN terminals would improve (Weidmuller terminals) with replacement; however, I would expect that the retention at almost all other ports would not improve. Most of these have post connections that are made with socket connectors. These sockets provide most of the retention force. Fabricating/purchasing new PWM cables might be a quick path to improve retention of these cables. Additionally, there are 3D printable retention items that can be explored,

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Did you have to send the old one back?

Yes you have to send the old one back - but not until after the replacement arrives.
They send a prepaid return shipping label for the box.

This glorious example of engineering and workmanship will never be repurposed.


That’s a great idea about the 3D-printed retention parts! Just taking a quick look at grabcad I found this roboRIO retention clip!

If I’m looking at it correctly, it looks like it can keep PWM cables firmly in place. Thanks for the input!