Chief Delphi - Methods of adding ballast to underweight robots

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- - Methods of adding ballast to underweight robots (http://www.chiefdelphi.com/forums/showthread.php?t=73459)

Re: Serious Ballast discussion

Might I suggest reading http://www.chiefdelphi.com/forums/sh...threadid=73430 ?

Yes, that is a serious discussion.

Re: Serious Ballast discussion

We've toyed with putting a copy of the McMaster-Carr catalog next to the battery, or adding a coffee maker. (The jous of being underweight ...)

Re: Methods of adding ballast to underweight robots

These threads are now merged. All further discussion can continue here.

Re: Methods of adding ballast to underweight robots

Steel sheet or plate under the chassis is a very good (perhaps best) method of weighting a robot, because it keeps the center of gravity (CG) as low as possible. Because the regolith is so slick, tipping robots should not be a problem this year, but if your CG is above the crater rail you could tip your robot over by slamming into the side rail (and it would not be recoverable as it would then be outside the crater).

Re: Methods of adding ballast to underweight robots

Steel plate is good, although not very dense. Lead is good as it's more dense than iron, but I would use gold -- it's 72% denser than lead and it would make your robot shiny. :)

Re: Methods of adding ballast to underweight robots

ADD more wheels, more wheels seemed to help in our tests. But thatz us, wheels are about a pound with bearings (overestimate).

Re: Methods of adding ballast to underweight robots

Last year we used a bunch of the old short bolts and star nuts from previous years' kitbot frames. We filled up two NoS energy-drink bottles and attached them to the robot. I can't tell you how many questions I got about those bottles last year...

Re: Methods of adding ballast to underweight robots

If you have to add weight with the poor cof of the wheels it would be best to ballance ths weight distubution so all the wheels see the same weight staticaly.

Re: Methods of adding ballast to underweight robots

I bet that there will be no shortage of FRC teams willing to donate their bots' extra weight to yours after their initial weighin.

Re: Methods of adding ballast to underweight robots

Nonfunctional decorations!

A few cold cathode tubes . . .
30 pounds worth of blinking LEDs . . .

Or you could add 30 pounds worth of sensors and related wiring to better control your robot.

Re: Methods of adding ballast to underweight robots

Quote:

Originally Posted by Gdeaver (Post 812942)

If you have to add weight with the poor cof of the wheels it would be best to ballance ths weight distubution so all the wheels see the same weight staticaly.

Indeed, for robots with power to all wheels, there is no need to emphasize weight over any particular wheels. Unfortunately, it appears that some teams will field robots with only some wheels powered, so it's important for those teams to put the weight over the powered wheels (within reason to prevent tipping, of course).

Re: Methods of adding ballast to underweight robots

Quote:

Originally Posted by Matt C (Post 812962)

Nonfunctional decorations!

A few cold cathode tubes . . .
30 pounds worth of blinking LEDs . . .

That would be amazing. I can picture it now...:D

Re: Methods of adding ballast to underweight robots

I was actually thinking of using a second battery to add more weight if we are under. The rules say we can't use more than two. Technically speaking only one would be hooked up at a time. That way between matches we just hook to the opposite battery that is strapped on. This way we'd always have a charged battery on the robot for those matches that are close to back to this would be benefical

Re: Methods of adding ballast to underweight robots

Quote:

Originally Posted by Stillen (Post 813118)

Uh, no they don't!

LAST year's rules allowed two, the main 12V and the smaller backup battery. THIS year's rules do not allow more than one. <R01-A>, <R11-A> first bullet, and more importantly, <R38>.

Quote:

Originally Posted by <R38>, the Manual

The only legal primary source of electrical energy on the ROBOT during the competition is the MK ES17-12 12VDC non-spillable lead acid battery, as provided in the 2009 Kit Of Parts.
Additional batteries may be purchased through a local MK Battery supplier. Teams may use other equivalent 12V batteries during development, testing and practice MATCHES. However, during competition MATCHES only one MK Battery, ES17-12 can be used on the ROBOT (this means NO pre-2007 batteries can be used during qualification and elimination MATCHES at any official 2009 FIRST competition).

Re: Methods of adding ballast to underweight robots

I think we will go with a system of steel plates that can be transferred from side to side so the weight stays equal on both drive wheels.

Thanks for all the suggestions from all of us at 1245!