Question about the definition of Cots Items 2023 Edition

I have been a bit distant from CD and the First community this summer and fall as I had to focus more on some other things. So, somehow, I missed the blast a few weeks ago that had the updated evergreen rules. I caught it this week though.

Anyway, After reading, I am intrigued and curious about this part…

  • Modify R302-E, to permit teams to use items created before Kickoff if they are “functionally equivalent” to a COTS item. Functionally equivalent items are items that closely resemble a COTS item in both form and function. Functional equivalents should be made using similar materials to the COTS original.

So, to me as reading this, it seems that this is allowing people to use items that they made rather than purchased; E.X. Gussets, gears, etc.

The question I had after reading this was (and I know CD is not the official word on this), is there a grey area between item and mechanism. Does this imply that one could take a Greyt shooter off a robot they are working with in the off-season, and mount it to this season’s competition bot legally? I apologize if this has been discussed already.

I know there has been a lot of discussion in the past about the reuse of parts and mechanisms.


How I see it…
I think the Greyt shooter, climber in a box, etc. would fall under “major mechanism”, not cots items.

a group of COMPONENTS and/or MECHANISMS assembled together to address at
least 1 game challenge: ROBOT movement, CARGO manipulation, FIELD element
manipulation, or performance of a scorable task without the assistance of another

And those purchasable shooters arrive as a collection of parts, not an assembled mechanism.
So, if you manufacture your own gussets and brackets that are similar to the stuff you can buy on WCP’s website, then could be seen as legal to reuse.


I think the biggest issue here would be something like a GreyT kit being already assembled. If you were to precut all the parts prior to kickoff, and then assemble on or after kickoff, I’d see nothing wrong with this.

If you’ve already assembled the components together for training/practice before kickoff, if you were to fully disassemble those parts (before, on or after kickoff), and then reassemble everything on or after kickoff, I’d think that is fine too.


I don’t believe that a GreyT shooter would violate this rule as it does not address cargo manipulation alone, you still need an intake + indexer to be able to score cargo

1 Like

I think it really depends on the exact wording of the rule. The rapid react R302-E allows reuse of an “assembly of COTS items per manufacturer specs, unless the result constitutes a MAJOR MECHANISM as defined in I101”. So, if “COTS” gets updated to “COTS or COTS-equivalent”, imo, if the assembly is not a MAJOR MECHANISM (easiest way is to just partially disassemble it until the parts are no longer major mechanisms) I think you’d technically be within the rules.

If that’s how the rules end up written then one could, in theory, bring over a COTS-equivalent chassis, 4 COTS swerve modules, a COTS-equivalent turret, a COTS-equivalent elevator, and a box of motors that all conveniently happen to fit well together and have a mostly-functional day zero robot (which IMO isn’t in the spirit of the rules).


Thank you all. Now that I see it here, I think that perhaps this is the big piece. Many of the other points are excellent too, but not any different than in other years. The exception now is that if we make our own parts that are similar to the GreyT, the wording of the change allows us to use those parts(we could not do so in previous years). Whether that extends to the full mechanism or not may indeed depend on the language of the game.

I am most interested because we opted out of the drive base. So if we assemble our test base (WCD), we may be legal if we only disassemble the pieces connecting the two sides. Then we can cut the sides to length and reassemble. This would probably be necessary anyway.

We did not manufacture our own gears, chain, wheels, or even extrusion, so pre-2020 rules would not allow for this, but if R302 is as open as it was for rapid react, we may be. :slight_smile:

When you all figure this one out, let me know.


If I’m trying to avoid grey area, I take this to mean that you can manufacture parts to a COTS design and use them. This would be 3d printing standard sized spacers or cutting your own gussets and plates to match a COTS component as closely as possible with the tools available.

That said, there seems to be a lot of gray area, can I cut my own bearing blocks with the same basic shape as a COTS part, but with extra lightweighting? How about one with a different center drop?

1 Like

Perhaps I’m not lawyering the rules enough here, but I’d say no on both accounts there.

If you add pockets or holes to remove weight, that’s now a custom part in my eyes that has the clear potential to give you an advantage over others using the actual COTS part.

If you change the dropped center, you’re very clearly changing the functionality of the bearing block in my eyes.

While I agree things like what material can these parts be made out of with regards to this rule is a little subjective, modifying/customizing the parts as suggested would be a violation of said rule.

(note that this is all very much my opinion and that I am not the 2023 Q&A).

1 Like

Dare I say the “spirit” of the rule is this: in years past you could stockpile COTS items (components/elements/parts), and unassembled mechanism kits (composed of COTS items); now everything is out of stock… so take this time to manufacture your own functionally equivalent items.

Stockpile items.

Don’t stockpile ready-to-go mechanisms.


I think the definition of “major mechanism” is the key to a clearer line. The definition originated in the “no cheesecaking” rule as I recall, and in the extra explanation under the definition “COTS mechanisms” are listed as one of the exceptions (i.e. one may infer they’re not major mechanisms).

The intention may have been to exclude COTS from the definition of Major Mechanism ONLY for the no cheesecaking rule… but unfortunately the other rule just points to the no cheesecaking rule as the reference for the Major Mechanism definition.

Recommendation: Break out the definition separately. Point each rule to that definition. State the COTS exception on the no cheesecaking rule, but not on the new rule… if that is the true intention.

1 Like

Digging up an old topic for a new look. We’d like to toss a bit of useful work to new CAD people. Designing gussets is a satisfying start. From sitting down to “here’s your laser cut part” can, in our situation at least, can happen in a few days. Obviously these would be functionally identical to gussets sold by multiple vendors. I doubt any robot inspector would make a fuss about it although we would be cutting from steel not aluminum so I guess they could. Would powder coating them (another advantage of longer lead time) be going too far?

Relevant scenario: A team made their own gussets, functionally equivalent to COTS gussets, for the 2023 season, and they powder coated them. Could they reuse these in the 2024 season?

I think the spirit of the original rule was to allow such reuse. If so, then I think the answer to tjwolter’s question is yes, it’s ok to add coloration to the metal parts.

If you look at the broader definition of COTS (i.e. extending beyond primarily FRC vendors to parts available worldwide), you will see plenty of metal parts for sale that are annodized, powder coated, etc., including brackets & gussets as well as stock extrusions and sheet I assume. This is also supportive of a team being able to add a color coating to their “COTS equivalent” metal parts (& also to stock I would think) in the off-season.

To add to this, rule R302 [E] makes an exception for painting and applies to functional equivalents to cots.


Because it is relevant to the broader topic of the thread, here also is the 2023 version of rule I101 (originally introduced primarily to limit cheesecaking… it includes the somewhat fuzzy definition of “major mechanisms” referenced in R302)

I think your biggest problem is the question of whether steel is functionally equivalent. If you use the same thickness gusset your steel one will be significantly stronger, structurally equivalent gusset could be smaller giving a space advantage, a steel gusset could be welded to steel frame, a steel gusset could be be used to provide ballast.

In reality these rules are largely up to teams to enforce on themselves. If your team would be just as happy with the COTS part then you’re probably within the rule, if your team would prefer to use the custom part then you’re probably outside the rules. Also worth noting that if you use your off season or reused gussets on a practice bot or prototype but not the comp bot then you still get use out of the parts without having to worry about the reuse rules.

1 Like

Sort of how I see it as well. We gain no advantage by doing this, other than having them look cooler as we are planning on a powder coat run in December for aluminum stock. And I’ve no doubt they’d pass inspection. But…technically not right and we do deal with technical matters, do we not?