2 batteries
 

does any one know if there are any rules about not haveing two of the 12 volt batteries on your robot. one that powers the robot and another for weight in the front of the robot.

i will upload a picture later today so that you can see what i am talking about.

Re: 2 batteries
 

Yes, there is a rule that specifically says you can only have one 12v battery on your robot.

"<R45> Items specifically PROHIBITED from use on the ROBOT include:
......
More than one primary battery, or more than one back-up battery"


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If you need ballast, find something else! A battery is a dangerous thing.

Re: 2 batteries
 

thanks for the information.

Re: 2 batteries
 

no its not allowed... just get a ton of steel that you can use as ballast and put it up there (=

Re: 2 batteries
 

In a game of speed, weight is never a good thing.

Is there a way that you wouldn't have to use ballast, or place the battery up front where the ballast would go.
You don't want weight on fast robots, (but maybe you do) any hints on what your robot is, or what it looks like.

Re: 2 batteries
 

Ballast is still governed by other rules. Be sure it meets the flowchart for allowables and that it is securely mounted on your robot. Tywraps do not count!

Re: 2 batteries
 

You can buy 5 and 10 lb iron weights at discount department stores, and the have a convenient hole thru the center for mounting.

Re: 2 batteries
 

get some lead i litterly have a ton of it in my back yard it works great as a counter weight.

Re: 2 batteries
 

And Small Parts still sells 27 pound bricks of lead. We have used them in the past as ballast (many, many years ago - ahhhh, for the good old days, when our robots always seemed to come in well under weight instead of well over... :( )


-dave



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Re: 2 batteries
 

Hmmm. Years of handling lead; that might explain some things... :D



On a philosophical note, does a battery count as a battery if it's not part of the electrical system? Yes, yes, I know the rules about one and only one 12v primary battery, but if it's not plugged into anything is it really a battery? Is it not just a battery shaped weight? Not that I'm advocating for using extra batteries as weights, but still an interesting point of discussion.

Re: 2 batteries
 

Is a battery a battery if it's not part of an electrical system? If not, then someone needs to go after Duracell and Energizer for false advertising.[/sarcasm]

Seriously, I would argue that a battery is a battery at any time. If it is only a battery when current is flowing, then anytime the main breaker is hit, the battery becomes a battery-shaped weight. If it is only a battery when hooked into the electrical system, then you're charging a battery-shaped weight. (Don't get any ideas.)

More importantly, a battery has the potential to suddenly become a spark generator at any time. As soon as it hits metal on both contacts, it becomes a safety hazard, but it may or may not be plugged into an electrical system. Is it not a battery then?

Re: 2 batteries
 

Gentlemen,
Although lead seems to be an ideal ballast material, remember that in some areas lead is considered a hazardous material. It may not be cut or machined at events and should be painted or coated to prevent students (and mentors) from ingesting contaminants while eating with their hands.

Re: 2 batteries
 

Last year we filled two acculator tanks with lead shot worked great because we were not using air and you can fit about 5lbs into one, (i think) and it is sealed with two plugs.

Re: 2 batteries
 

Ahh, so a battery by any other name is still a battery. I think this is the most important argument against using a battery as a weight, especially when there is plenty of other heavy stuff around that can be used. How about a box of old motors? ;)

Re: 2 batteries
 

...the old motors would have to be currently available COTS :)

Re: 2 batteries
 

How about two one-gallon jugs of water?


Good preparation for next year...

Re: 2 batteries
 

Hmmmm......

We need about that exact weight. I wonder ...........?????

lead, steel, water ?

Re: 2 batteries
 

And when is a potato, just a potato?

Re: 2 batteries
 

If the battery is not plugged in, and its protected with AM Plugs, is it not just a 13 lb NFD?

Re: 2 batteries
 

We used a piece of railroad one year. I came back to find that my fellow mentors had lashed said railroad directly above the RC. Incredibly, it did not end horribly.

Re: 2 batteries
 

Use lead bricks, for the win.

Re: 2 batteries
 

Did you insulate the lugs/connectors? Because if you didn't, it's an accident waiting to happen.

Re: 2 batteries
 

Mean Dave, just plain mean!!! (and besides Gasoline is more fitting to this year's game)

Re: 2 batteries
 

Only allowed if another robot on the same alliance uses paper towels for ballast.

Re: 2 batteries
 

We're concerned about speed, and we're about 10 lbs under weight, so we're considering using a magnesium anvil for ballast. That would give us the extra weight we need to balance the robot, but not weigh so much that it would slow us down noticeably.

Re: 2 batteries
 

You need to go back and put some more stuff on. Your robot obviously doesn't have enough functionality.

Re: 2 batteries
 

Al is correct. You can't make your robot 10lbs underweight and still have all the functionality you need.

Re: 2 batteries
 

What functionality do we need in addition to being able to knock off and catch the ball, or scoop up the ball automatically, launch the ball over the overpass (or onto the overpass as needed), and run 10 second laps while possessing the ball?

We really couldn't think of anything else....and we have not put any lightening holes in the robot anywhere.

But Al is probably right :)

Re: 2 batteries
 

It doesnt dispense Mountain Dew!

Re: 2 batteries
 

Oh...well, that's ok, because our team is more of a Dr. Pepper team

Re: 2 batteries
 

Blasphemy! Everyone knows Mountain Dew is roboteer fuel.

Re: 2 batteries
 

We're 15 lbs under. We must be wayyyyy lacking in functionality....

Re: 2 batteries
 

Add a couple of cases of Mt Dew (or Dr Pepper if you can stand that vile stuff - reminds me of cough medicine).

Re: 2 batteries
 

I'ts actually carbonated prune juice.

Re: 2 batteries
 

And if I remember correctly (and our scale is working properly), we're about 80 pounds with the battery and bumpers... :ahh:

And Al, thanks for the idea of painting the lead. We're about to cut some lead ballast for our robot, and I was quite concerned about the inspectors deeming it a hazardous material unlike our anything goes mentor. Paint (hopefully not lead based!) sounds like an ideal solution.

Re: 2 batteries
 

Back in the days when we were adding lead ballast to our robots, we used to coat the lead brick with liquid plastic tool-dip from the hardware store. It makes a very nice, tough coating that completely traps any stray particles. It stands up to a reasonable amount of abuse, and if you need to later it is relatively easy to peel it off.

-dave



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Re: 2 batteries
 

Okay, easiest way to add weight is to zip-tie boxes of bolts onto the robot. They even come conveniently with a handle...

On a second note... make sure you seal them tightly...

Re: 2 batteries
 

I agree, and it also adds a nice non slip surface.

Re: 2 batteries
 

We found some spray on rubber coating at OSH that seems to have done the trick quite nicely.