minibot battery

[martin417]

According to this Q&A this is expressly forbidden.

01-25-2011, 07:25 PM
2011FRC3238
Junior Member

Join Date: Dec 2010
Posts: 5
Minibot battery modification
Is it permitted to separate the cells of the minibot battery (keeping the electrical configuration intact)?

#2
01-31-2011, 03:39 PM
GDC
Game Design Committee

Join Date: Jan 2006
Posts: 2,762
Re: Minibot battery modification
This would be a violation of R92-C.

[WileyB-J]

Originally Posted by martin417

According to this Q&A this is expressly forbidden.

no kidding. heres another shot of it:

[dodar]

They let that compete?

[Mike Betts]

Originally Posted by martin417

According to this Q&A this is expressly forbidden.

Martin, Eric, et al,

The problem is that FIRST did not publish a search-able, consolidated Q&A this year and most events did not have internet access available to the inspectors.

If a team presented a Q&A to support their claim to legality, it was accepted. However, if an inspector "remembered" seeing a Q&A stating something was illegal, the LRI was forced to rule in favor of the team.

As an inspector, similar rule "violations" happened to me twice in FL and I was forced to let the violations go in favor of the teams because the rules did not expressly forbid it.

Mike

[dodar]

Originally Posted by Mike Betts

Martin, Eric, et al,

The problem is that FIRST did not publish a search-able, consolidated Q&A this year and most events did not have internet access available to the inspectors.

If a team presented a Q&A to support their claim to legality, it was accepted. However, if an inspector "remembered" seeing a Q&A stating something was illegal, the LRI was forced to rule in favor of the team.

As an inspector, similar rule "violations" happened to me twice in FL and I was forced to let the violations go in favor of the teams because the rules did not expressly forbid it.

Mike

Like what? Just curious to know because I really never remember hearing anything at the regional.

[Mike Betts]

Originally Posted by dodar

Like what? Just curious to know because I really never remember hearing anything at the regional.

Mike,

Why should you have? Without a comprehensive Q&A, the rulings went in favor of the team...

For example, what if a team had a minibot magnet with an integral metal cover? Many COTS magnets, such as a cabinet latch or some refrigerator magnets, are sold this way... This GDC insight may have been overlooked in favor of the team...

Without the Q&A, the LRI is forced to give the team the benefit of the doubt.

Teams are likely to print out Q&As that support their design decisions but not those which point out their "illegality". I know of no inspectors that print out over 300 GDC "gems" and, even if they did, there is no time to manually search that paper stack.

An electronically searchable database (like this one from last year) is the only solution and FIRST decided not to provide these this year...

We do the best with what we have...

Mike

[AlexH]

So what's the difference between splitting the battery into two 6v packs and running it in series to get 12v or removing/changing the gearbox from the ftc gearmotor?

[PAR_WIG1350]

Originally Posted by AlexH

So what's the difference between splitting the battery into two 6v packs and running it in series to get 12v or removing/changing the gearbox from the ftc gearmotor?

One is legal, the other isn't. It isn't really something the GDC is likely to give their reasoning for.

[Cascade]

Please see page 67. I believe you will find an answer there as well as other places in the official GDC consolidated response to questions.

Please also see Update 5. In addition, some teams came to regional events with a minibot battery wrapped in transparent wrapping. The only official battery is the Tetrix battery wrapped in the black wrapping material.

Good luck, everyone.

[Mike Betts]

Originally Posted by Cascade

Please see page 67. I believe you will find an answer there as well as other places in the official GDC consolidated response to questions.

Please also see Update 5. In addition, some teams came to regional events with a minibot battery wrapped in transparent wrapping. The only official battery is the Tetrix battery wrapped in the black wrapping material.

Good luck, everyone.

May I ask where this document came from? I traded emails with Al Skierkiewicz on the 9th and it did not exist to his knowledge. It was not available at FL either...

I just checked the First site Manual, Team updates and KOP pages and saw nothing.

Could you provide a link?

Mike

[Mr V]

There is a good reason to make separating the battery illegal. The heavy duty shrink wrap is for insulation as well as holding the batteries together. If you've dissected one of these "sub C" style of battery packs you'll find that the the cells are arranged with half of the positive terminals "up" and half of them "down" so it isn't hard to create a short circuit creating a "loop" between 2 or more batteries. Allowing that shrink wrap to be removed creates the need to have a standard as to what constitutes appropriate re-insulation thus putting additional demands on the inspectors.

I did notice in the Cascade/Olympic pits on Fri at least one minibot go by that had a clear wrap which made me think it wasn't a legal battery.

[ssi]

All a clear wrap means is that it is an older Tetrix battery.

[Al Skierkiewicz]

Mike,
It was emailed to LRI's on the 10th or 11th. Do you have it now? I can send it to you.
This is the section...

Minibot battery modification
Posted by 2011FRC3238 at 01/25/2011 07:25:54 pm
Is it permitted to separate the cells of the minibot battery (keeping the electrical configuration
intact)?
Re: Minibot battery modification
Posted by GDC at 01/31/2011 03:39:37 pm
This would be a violation of R92-C.

It is simply a violation because of the words "C. no more than one 12V rechargeable NiMH battery pack identical to those supplied in the FTC kit of parts"
This is keeping with the modification rules in the body of the robot rules <R55> M.

[Cascade]

Originally Posted by ssi

All a clear wrap means is that it is an older Tetrix battery.

Agree; however, when you read the rule then look at Team Update 5, it is pretty clear the only allowable battery is the attached:

http://parts.ftcrobots.com/store/det...&c=1&t=0&l= 0

[Al Skierkiewicz]

Cascade,
There is no difference in the batteries, simply a change in heat shrink by the manufacturer.