Tetrix Switch not allowed?

We just got back from the Niles competition in michigan and when we had out minibot inspected, we had one of the tetrix switches that came with the kit that triggers when hit by the pole, then we had a toggle lamp switch on top for the top of the tower.

While having it inspected, were told that both switches are technically not allowed because the tetrix switch is not a light switch and the lamp switch is not allowed because it is a LAMP switch not a LIGHT switch. We were passed however but told that at the state level this would not be an allowed minibot. Also, there were many teams there that had multiple regular limit switches on their bots and when asked, they said they had no opposition from minibot inspectors about limit switches being illegal.

Has anybody had a similar experience with having their minibot inspected?

I was the inspector you spoke to. The Tetrix switch is included in the list of Approved Tetrix Parts for minibots.

A push button switch might be considered a common household light switch, if it is sold as a “light switch”. See this response on the official Q&A forum. Also see Team Update 12, which includes the following: “…anything sold as a ‘light switch’ for household use is allowed.” In case an inspector is unsure about your switch at a future event, you should be prepared to show that it was sold as a “light switch”.

Therefore, “light switches” permitted on the MINIBOT are not confined to those used in wall mounting boxes

you were completely legal from what i can tell on the switches.

how anyone came under the impression a tetrix switch is not allowed is beyond me.

We were actually forced by inspectors to switch to tetrix switches, which are legal.

Because it is “hidden” within. R92, stating that Tetrix NXT components are allowed. All sensors on that list are allowed, which included your switch.

However, the inspector, IMHO, was correct in saying your “lamp switch” is not marketed as a light switch. Do some research and shop around for one that is marketed as a light switch that will suit your application. As an alternative, there are limit snap switches that are not momentary and exceed your contact amp requirements. Push once, it’s on, push again, it’s off. digging for what you need is part of the game.:slight_smile: :slight_smile:

Personally, I find this entire subject to be complete foolishness. The FIRST rule book specifically tells us not to “Lawyer the rules”, but then FIRST turns around and starts applying unneeded legalistic interpretations on an engineering technicality. FIRST is doing the very thing that they tell us not to do. This is just plain foolishiness. We are engineers, not lawyers. The fact the the rules have been reduced the the statement “you must have packaging with the word ‘light’ in the product description” is hilarious. How about a little common sense here? I have no idea why on earth FIRST is choosing to impose a rule like this on the teams.

If it is not a competitve advantage and it is not a safety risk, it should not be a rule, plain and simple. “Because we say so” might be sound logic for 6 year olds, but not for engineers.

Back in the 90s, the rule book was filled with all sorts of stupidity like this. Many of the older teams worked very hard with FIRST for years to get most of these type of rules removed for the big robots; it seems the new leadership of FIRST have lost sight of the reasoning behind many of the decisions we made back then.

This is an excellent effort by FIRST to introduce students to code enforcement. I deal with inspectors constantly in my business and there is a skill set to be gained by documenting and presenting you interpretation and design to inspection. This is a real world exercise. This is a positive not a negative.

Jim is right on this one. Learning to build and design within given criteria is essential to engineering and problem solving, but FIRST already fosters this without imposing these kind of requirements.

It’s one thing to make the game challenging, but I think we’ve reached a point where teams are looking for ways to bend/lawyer to rules so we can do the thing we love: innovate.

Fewer contstraints = more solutions
If FIRST wants us to innovate, there should be as few design constraints as possible. There are really only 3 reasons there should ever be design constraints in the FRC.

  1. Safety
  2. Fairness / Unfair Competitive Advantage
  3. Robot Control in the competition setting.
    If something does not fall into one of these 3 categories, it should not be a design constraint. The light switch rule is a clear case of needess pettiness in the rules encoding for no obvious reason. The vendor of a component should NEVER be a design constraint unless the functionality of the component specifically addresses one of the 3 catagories above.

I have to take Jim’s side here, the limits on switches (no pun intended) are silly.

“The crew shuts down Aquarius to conserve power, subjecting them to freezing conditions. As another problem arises—the dangerous buildup of carbon dioxide exhaled by the astronauts—an engineering team quickly formulates a solution which allows the Command Module’s square air cleaners to be used in the Lunar Module’s round receptacles.”

This describes one of my favorite movie scenes. The ground based crew has to find a solution to the air cleaner / carbon dioxide problem, and whatever solution they find has to only include materials and tools that are already on the Lunar Module or Command Module.

I think that is some pretty good / innovative engineering.

No sillier than not allowing individual fuse protection on the Tetrix motors. You have to design around the constraints imposed by the vendor. FIRST is no different than any other vendor. Constraints, IMO, foster innovation. Right on the money with Appollo 13. :slight_smile: :slight_smile:

One of the Minbot inspectors at LA asked me how much a switch had to weight before it stopped being a “light” switch and started being a “heavy” switch. He then pointed to a very small (and obviously light) switch being used on a minibot.

Ahhh the multi-valued use of words in English, so handy at times


You have made my evening… I can go to bed with a smile on my face… Thanks.


Congratulations to the inspector on having a very dry sense of humor.
(I hope!)

Just to keep this thread grounded, the initial limit on switches was an attempt to involve FTC and FLL teams in minibot construction. The idea was to make it easy for them to build a minibot and bring it for your use.

While I agree with you Al, I begin to wonder once again why this was a goal that FIRST as a whole possessed to begin with. Aside from funding, if I were on an FTC or FLL team and had the desire to partake in FRC I would do so. I do not see the need to force one down the throat of the other.

It is my impression it was meant to be a celebration of the twentieth anniversary of First.