minibot battery

[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 Mike Betts

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

I saw Al's response as well; thank you. I don't remember having this sent to me. However, my download folder says I pulled this down on the 11th of March. It was posted by Frank Merrick. I remember pulling this off the FIRST site from the competition manual section. It is no longer there, however. I checked the FIRST site when I got home from the day's competition on the 11th and it was there. I immediately used it to help sort out a minibot question that came up in San Diego. That's what I recall anyway.

Thanks

[Cascade]

Correction: I followed the link from my download folder, which shows this was clearly posted in the forum section on the FIRST site. I have either lost my mind or it was never there because I can no longer find it. Below is the link where it was.

http://forums.usfirst.org/attachment...9&d=1299697295

[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.

[Cascade]

Yes, agree with you, Al: 12 vdc, 3,000mA. But some teams gobbled onto the word "identical" in rules and when you look up the Tetrix battery it is currently in the black wrapper. Too much and to literal, I know. That just seems to be where we are this year on some issues like light switches for example.

Take care

[Al Skierkiewicz]

Cascade,
Depending on when you purchased an FTC kit it may have been delivered with clear heatshrink or black. So either meets the rule of identical to that supplied in the FTC Kit.

[Cascade]

Originally Posted by Mike Betts

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

Mike, found it again. Look in the LRI Forum, second post from the bottom, by fmerrick. The .PDF is there.

Thanks

[Cascade]

Originally Posted by Al Skierkiewicz

Cascade,
Depending on when you purchased an FTC kit it may have been delivered with clear heatshrink or black. So either meets the rule of identical to that supplied in the FTC Kit.

Very good; thank you for the assist.

[Alice141]

I was wondering about the wording of the Minibot rules:

The FRC manual sec4:
R92"exactly one 12V rechargeable NiMH battery pack identical to those supplied in the FTC kit of parts (PN W739057)"
But
"No more than one HiTechnic DC motor controllers"

Since FIRST did not choose to say "No more than one battery", are you required to have the 2lb battery on your Minibot?

Thanks,