Re: Methods of adding ballast to underweight robots
 

If you are using pneumatics, you can put as many cylinders (not to be confused with accumulators) on as you want. If you hook them up to your 60 psi side, you will gain extra air storage while solving your weight issue.

Re: Methods of adding ballast to underweight robots
 

Might I suggest the Tumbleweed weight gain diet?
http://www.chiefdelphi.com/media/photos/31418
I would say its one of the fastest ways to add a few pounds to your bot! :P

Re: Methods of adding ballast to underweight robots
 

Armor would be sweet hehe:cool:

Re: Methods of adding ballast to underweight robots
 

you could add underglow, LEDs/Neon lights, to your robot. :cool:

Armor would be sweet. Or you could take 30 lbs worth of tools and strap them to the robot. Then you'd never have to go back to the pit! :D

Re: Methods of adding ballast to underweight robots
 

Please don't do this. While I don't see anything in the rules to make it explicitly illegal, I consider it closer to the bad side of the "cheating" vs. "clever engineering" scale. The rules do say not to use extra tubing for this purpose, and I'd use that as an indication of the intent of the rules.

Re: Methods of adding ballast to underweight robots
 

Throw in some diamond plate and make the delorean =]

Re: Methods of adding ballast to underweight robots
 

I'd like to start this discussion up again. We are underweight but also have skewed weights over each wheel. I've been thinking of riveting 2 foot long pieces of 1x1 (sealed on one side and removable cap on the other) to each corner "tier" (vertical beam on the bot that essentially form a box) and filling them with steel or lead shot. This way, we can quickly add more or less shot to each beam on thursday to adjust weight with each wheel resting on a cheapo bathroom scale.

Any thoughts?

thanks, Vivek

EDIT: What sort of store would have lead or steel shot locally? I know Mcmaster has it but shipping will be ridiculous.

Re: Methods of adding ballast to underweight robots
 

dimond-plate is obviously the best choice:D

Re: Methods of adding ballast to underweight robots
 

Try a local gun store. They should have lead shot in sacks for use by shotshell reloaders. They will have several different sizes...your choice.
Not cheap but you won't have to ship it..

Re: Methods of adding ballast to underweight robots
 

To err on the safe side, I should have some ideas on alternatives to lead shot.

I just got the idea to use pennies instead. They are cheap and easier to use.

With 2.5 grams per penny, 20 pounds of pennies costs about 36 dollars which isn't too bad.

-Vivek

Re: Methods of adding ballast to underweight robots
 

I think you could use pennies ... They are just about 25% less dense than lead so that's not bad. Better than steel which is something like 30% less than steel
Steel bolts are cheap though...put them or pennies in a PVC pipe...

tungsten is what you really want... but expensive...twice as dense as copper..
pretty cool stuff...

R

Re: Methods of adding ballast to underweight robots
 

Turns out newer (past mid 1980's) pennies are actually 97.5 percent zinc and only have a 2.5 percent copper coating. Who knew?

I think either the pennies or just scrap bolts we have lying around will work. I'll have to take a look at our junk bins later this week.

-vivek

Re: Methods of adding ballast to underweight robots
 

our team used rebar in 2007
it worked great for our purposes

Re: Methods of adding ballast to underweight robots
 

I think it is important at this point to remind everyone, that adding weight needs to be done in a manner that will not cause damage to the field or other robots. For that reason simply using tywraps to hold practice weights or lead blocks in place is not recommended. Use something much more reliable like a threaded fastener. Lead, if used, should be sealed or painted to minimize contamination and as Russ pointed out earlier, should not be machined in the pits.
From the pneumatics even if you don't use the system, the compressor and air tanks as well as actuators can be used as ballast using their normal mounting hardware.
R71> In addition to the items included in the Kit Of Parts, pneumatic system items specifically permitted on 2009 FRC ROBOTS include the following items. All included items must be“off the shelf” pneumatic devices rated by their manufacturers for pressure of at least 125psi, and used in their original, unaltered condition (except as required for assembly with other
components).
A. One or two additional Clippard air storage tanks (Clippard Part Number AVT-32-16), equivalent to those provided in the kit. This means that up to four, and no more, Clippard air storage tanks can be used on the ROBOT.
Lengths of heavy gauge wire can also be used and easily secured with wire ties. #4 or even #0 can be a way to distribute weight easily while increasing the robot weight.
I once had a team mount up a bench vise and another team mounted a toolbox to compensate for the loss of an arm or ramp that they decided was causing more harm than good. Both used heavy, threaded fasteners and of course fell under the COTS parts and cost basis sections of Robot Rules.

Re: Methods of adding ballast to underweight robots
 

Any sporting goods store (and most Walmarts) sell steel BB shots for air rifles. That being said, I'd use pennies as noted by others...

If you go the "shot" route, please be sure that the "removable cap" you use is very secure. In the event that your robot tips over, pounds of "shot" spilling onto the floor will cause a very dangerous situation for referees, field reset, et cetera and will almost certainly get you disqualified...

Regards,

Mike