Minibot switches...

[tuyauxtu]

So, just wondering if any teams have gone out on a limb and used a "switch" made from the allowed minibot materials with the purpose of mimicking a two-way switch but saving weight over a purchased item? If you've done this and been inspected at a competition were you allowed to compete in this manner? Feedback either way would be appreciated.

[Al Skierkiewicz]

tuy,
You can only use limit switches, a max of two lighting switches, and Tetrix switches on the minibot.

[jvriezen]

That doesn't sound right to me, Al. What's the problem with fabricating your own switch using the allowable MINIBOT materials such as aluminum and rubber bands? Can you cite a rule or Q&A ?

John Vriezen
FIRST FRC team 2530 "Inconceivable"
Mentor, Drive Coach, Inspector

[Al Skierkiewicz]

John,
<R92> The following items are the only permitted materials for use on the MINIBOTS:
M. limit switches,
N. no more than two common household light switches,

The Q&A answered that only the Tetrix Rocker Power switch could also be used as it is a Tetrix part.

I am not aware that any other parts were approved as electrical and would expect that the Q&A would agree. In the case of the minibot, electrical using the list above, is the simplest problem to overcome. As always, the Q&A is the only definitive answer.

[Nick Lawrence]

If you can afford it, you can go the route my team went and replace the fuse on the battery lines with a lower-rated one (we use 7.5A) and blow it once you get to the top and briefly stall the motors. We replace that fuse every match.

It may not be the most cost-effective solution, but it's extremely simple.

-Nick

[galewind]

we're using the tetrix power switch (and a custom aluminum lever) as well as the 7.5A breaker

[jvriezen]

A breaker would not be permitted.

John V
FRC Team 2530
Mentor, Drive Coach and inspector.

[PAR_WIG1350]

Originally Posted by galewind

we're using the tetrix power switch (and a custom aluminum lever) as well as the 7.5A breaker

Agreed, breakers aren't allowed, but if you replaced the fuse on the tetrix battery with a 7.5 A fuse, that would be legal.

[DonRotolo]

Fuse, breaker - same thing (just as long as what's used is a fuse)

Our minibot inspector at NJ agreed that the Cherry E79 listing off Mouser said "Limit switch" somewhere and so he accepted it.

I just wish I could be confident it will be accepted in Virginia and/or CMP

[galewind]

yeah, fuse, fuse... not breaker. sorry.

[Al Skierkiewicz]

Don,
I looked at Mouser and at Cherry Switch and could find no mention of "limit" in either location. If you have a page where this switch is listed as a limit switch, you merely have to bring a copy with you to show the inspection team. The Q&A responded to a question from Team 599 "4) A limit switch is anything marketed as a "limit switch"."

[IKE]

I really dislike the "marketed as" wording.

For instance, is this switch illegal (not marketed as a limit switch)

http://www.radioshack.com/product/in...er Value=SPDT

Are these too illegal (sorry, those are micro-switches, not limit switches)
http://www.mcmaster.com/#micro-switches/=bhhquw

Yet this one would be perfectly legal (It does have the term "limit" in its description):
http://www.amazon.com/Copper-Termina.../dp/B002P4XQY6


When the original Q&A called for a "light switch" as the kind mounted in a wall box, we made up some SPST, SPDT, and DPDT switches with blades and rubber bands, and mounting brackets and used a scale to make sure they applied 6N of force. When parents came in to look at the mini-bot, they laughed at me and explained there were way better switches at Radio-shack or online. This is funny the first time you defend the rule. The 20th time though, is pretty annoying.
Then update 12 came out to which I believed was a coming around to something more reasonable.
Now I am a bit concerned. I can find the same switch on 3 websites. 2 being frequent parts suppliers, but are those technically illegal? The other source I would rarely/never go to to buy an electrical component, but because it has the proper descriptor, should I? If I purchased switch XYZ from A (illegal description), and then show up with paperwork from C (legal description for the exact same switch), do I have to lie and say I bought it at C, or can I say i bought it at A, after finding it through C...

I will try to get our Q&A guy to post this question.

[Al Skierkiewicz]

Ike,
The three switches you link to are commonly shown and marketed as limit switches. Everyone knows them as limit switches, they come in the KOP as limit switches albeit with different actuators. Limit switches are legal on the minibot and have been from the first day.

[IKE]

Originally Posted by Al Skierkiewicz

Ike,
The three switches you link to are commonly shown and marketed as limit switches. Everyone knows them as limit switches, they come in the KOP as limit switches albeit with different actuators. Limit switches are legal on the minibot and have been from the first day.

Yes, but 2 of the 3 are not marketed as such from their sources. I agree with you that almost everyone knows this.
There are some other switches that I really want to use that I have found at Lowes or Home depot in the home lighting section. The packaging says push button switch. It is a 125V switch that can clearly be used to turn a light on at home. It is readily available, but I don't know if every inspector will let me use this.

There is a switch at Radioshack that I would love to use. I found it in the limit switch drawer, but it is labeled "push button" on the packaging. I have found other "push button" style switches as limit switches on other websites. Much like the "limit" switch in the above example says "micro switch" not limit switch.

When update 12 came out, I thought we were beyond the bring your packaging, bring the website, bring the marketing brochure from the manufacturer... but I have heard from other teams that their switches weren't allowed during week 2 events.

I am not trying to lawyer the rule, I am just trying to figure out how we will be held accountable for choosing the switch we choose to use.

[jvriezen]

This might deserve clarification from GDC Q&A, but I don't see anywhere that its been said that you have to purchase a switch from the source that markets it as a limit switch.

If Mfgr X sells a limit switch with part # N through multiple marketing channels, and at least one of those channels 'markets' it as a limit switch (or household light switch) and you buy it through another marketing channel, that should be ok.

As a practical matter, anything that it is quite clearly something that 'ought' to be marketed as a limit switch or household light switch will not invite added scrutiny from an inspector. They don't have the time to be asking for documentation on every switch, only questionable ones.

In my point of view, the 'marketed as' requirement allows the issue resolution to go to a neutral third party and tries to avoid long drawn out arguments between an LRI and a team member. It provides a mostly cut and dried resolution path.

John Vriezen
FIRST Team 2530 "Inconceivable"
Mentor, Drive Coach, Inspector