Methods of adding ballast to underweight robots

[Paul11]

Our robot weighs only 90 lbs fully loaded any suggestions on how to get it up to 120? http://www.chiefdelphi.com/forums/im...s/confused.gif

[MrForbes]

If you want it to weigh 30 pounds more, you could add 30 pounds of metal to it. I suggest steel plate, screwed to the bottom of the robot chassis.

[Arefin Bari]

Yup, first thing you should add any braces you feel that would be useful.

If that's not enough, make a trip to Sports Authority and buy a 25 pound weight and put it on your robot.

[EricH]

Add another mechanism to improve performance.
Leave it at 90 lbs.
"Forget" to take your bumpers and trailer hitch off for weigh-in.
Find a 25-30 lb chunk of steel and bolt it on.
Add decorations.
Add armor--Lexan works.
Add more wheels (or not).
Experiment with a properly shielded propeller system.

[Paul11]

We are going to try to get the weight on the two drive wheels in the back. It is a 18"x6" flat surface. Any mounting would happen off of two 18" bars of 80/20.

[MrForbes]

18 x 6 = 108 square inches. Steel weighs .283 lbs per cubic inch. You'd need 106 cubic inches of steel to get 30 lbs. That's about an inch thick, covering that rear area!

Cast iron sports weights are about that thick, if you got three of the 10 lb weights they might fit back there...maybe...

[Tom Line]

If you used tubular construction, you can drill a hole in a tube and pour in some lead shot. Cheap, effective, and it doesn't change the look of your robot any.

[XXShadowXX]

isn't Lead considered poisonous, much like Mercury and Radon, being the reason that FRC teams can't use lead solder at FIRST events?

[Tom Line]

Originally Posted by XXShadowXX

isn't Lead considered poisonous, much like Mercury and Radon, being the reason that FRC teams can't use lead solder at FIRST events?

Vaporized lead can be hazardous if you ingest / breathe it, yes. However, I have been unable to find the rule you're talking about regarding not using lead solder at competitions. Can you please cite it?

Also, I would suggest that there are many dangerous chemicals inside both the battery and the control boards (heavy metals, lead, etc). Unless you plan on somehow eating your control components and battery, they are usually benign. Having lead sealed inside your frame would hardly be dangerous - though it might make quite a mess if you managed to fracture your frame

[Doctorwho]

The weight problem hit our previous year's robot, we used a 14 pound steel plate bolted to the chassis to solve the problem.You could go to your local welding shop and see if they have any scrap steel plate that they want to get rid of.

[XXShadowXX]

Originally Posted by Tom Line

Vaporized lead can be hazardous if you ingest / breathe it, yes. However, I have been unable to find the rule you're talking about regarding not using lead solder at competitions. Can you please cite it?

Also, I would suggest that there are many dangerous chemicals inside both the battery and the control boards (heavy metals, lead, etc). Unless you plan on somehow eating your control components and battery, they are usually benign. Having lead sealed inside your frame would hardly be dangerous - though it might make quite a mess if you managed to fracture your frame

This is true...

it was in the safety quiz (a question about using lead free solder, and i got it wrong)
also John Antilla mentioned that it after he said we had a electronic heat gun..

but i don't know the rule in question

[Wetzel]

Originally Posted by Tom Line

Vaporized lead can be hazardous if you ingest / breathe it, yes. However, I have been unable to find the rule you're talking about regarding not using lead solder at competitions. Can you please cite it?

Also, I would suggest that there are many dangerous chemicals inside both the battery and the control boards (heavy metals, lead, etc). Unless you plan on somehow eating your control components and battery, they are usually benign. Having lead sealed inside your frame would hardly be dangerous - though it might make quite a mess if you managed to fracture your frame

In the safety manual they ask teams not to use lead solder at events.

Originally Posted by FRC Team Safety Manual

NEW - At FIRST events: Use lead-free solder only and solder with electrically heated soldering iron/gun only.

Wetzel

[Al Skierkiewicz]

I had hesitated to include this in my first post, but robot rules do not prevent you from mounting unused 2009 KOP motors as ballast. Use the mounting holes and hardware meant for the motor, just tie off and insulate the wires so that they don't come in contact with any active circuitry.

[Lil' Lavery]

It had been alluded to earlier in the thread, but keep in mind that ballast is a great way to move/control your center of mass. Where you place it will have a great impact, and can be used to improve robot control, improve acceleration, and prevent tipping.

Also keep in mind that this brand new weight will change your robot handling, and your drivers may have to re-learn how to drive the robot.

[Andrew Schreiber]

Originally Posted by XXShadowXX

isn't Lead considered poisonous, much like Mercury and Radon, being the reason that FRC teams can't use lead solder at FIRST events?

You are correct, steel shot is also an option.

397 does use lead to weight our robot for testing. We have several large blocks of it (let me tell you, DONT pick up two brick sized chunks of lead) We just make sure we wash our hands after it. One option is to open up one of the Bimba tanks and fill it with the lead shot then mount that. Frankly, if you break one of those you have bigger problems to worry about.

Whatever you do, keep your weight low and centered over your driven wheels.