Using Helium to reduce your weight!

**PJ-27** · 15th March 2011, 10:01

Ok, so I've thought about whether this would be allowed for a long time, and often dispelled it without further thought, but figured I'd get other opinions.

The idea is simple, but helium filled pockets inside the robot, to reduce it's weight (since helium is lighter than air, it'll rise, counteracting the effects of gravity.) I do believe the robot's mass will remain the same, although my Physics is a little rusty...

Obviously this has issues, volume to lift of helium is pretty low (talking grams from a single balloon) and they can be prone to popping. So don't know whether this would be effective or legal in the rules.

Just occurred to me since a lot of people seem to be putting magnets into their robots, producing the opposite effects of the balloons, increased mass, same weight, but offers an advantage withing the rules.

Any thoughts?

**woody** · 15th March 2011, 10:18

Mass is the constant ...weight varies with gravitational pull..and helium balloons

.

You could reduce the weight of the robot with helium balloons but not the mass.

IF you made a 200kg bot and added 100kg of lift then under the rules it should be legal as it would weigh 100kg....however ANY reduction in lift ...ie a leak or popped balloon would instantly render the bot illegal.

To get lift from helium balloons you need volume ...

Helium has a lifting force of 1 gram per liter. So if you have a balloon that contains 5 liters of helium, the balloon can lift 5 grams.

1000 liters = 1 kg of lift ...etc

**psychostorm** · 15th March 2011, 11:15

Personally I'm waiting on people to discover there's steel in the weighing scales

The added thing about helium would be you'd need to keep the wheels on the ground as no flying robots are allowed currently.

Could someone explain to me, why these magnets are legal?

I mean asides the obvious safety hazard of a machine dropping onto a Steel/Hardox floor & an avoidable stray magnetic field in a Tx area - surely that machine would breach the 30 pound weight limit as stipulated in the rules.

Bear this in mind for the responses:
Despite the presence of a unit of mass in the rule- it doesn't mention mass anywhere in the rules.
There is a unit of force that would still be valid, due to weight being a firce.

**PJ-27** · 15th March 2011, 11:16

Mass is the constant ...weight varies with gravitational pull..and helium balloons

.

You could reduce the weight of the robot with helium balloons but not the mass.

That's what I said wasn't it?.........

To get lift from helium balloons you need volume ...

Helium has a lifting force of 1 gram per liter. So if you have a balloon that contains 5 liters of helium, the balloon can lift 5 grams.

1000 liters = 1 kg of lift ...etc

So 200 balloons for 1kg..... Hhhhhhmmmmm.

Could make a robot like a Zeppelin! Then I would call it Lead Zeppelin!

Thanks,

**PJ-27** · 15th March 2011, 11:22

@psychostorm

My plan with the Helium is to just reduce the weight, not completely remove it, so it would still be on the ground.

As for no flying, surely 360 breaks that rule? It never has all 4 wheels on the ground! *jokes*

I could always use Hydrogen instead of Helium, more lifting force.........

The magnet thing is tricky, the scales don't take into account the additional down force of the magnets, which does increase the robot's weight.

I think it's a neat solution, if a little sneaky.......

**woody** · 15th March 2011, 12:14

That's what I said wasn't it?.........

I didn't disagree did I ? .........

The magnet thing is tricky, the scales don't take into account the additional down force of the magnets, which does increase the robot's weight.

I think it's a neat solution, if a little sneaky.......

I agree ....

Eventually... after DM regularly trashes the oppostion... this loophole in the rules will be closed.

**psychostorm** · 15th March 2011, 14:58

Originally Posted by PJ-27

@psychostorm

My plan with the Helium is to just reduce the weight, not completely remove it, so it would still be on the ground.

What happens if a spinner reduces the remaining mass to less than the uplift of the gas?

As for no flying, surely 360 breaks that rule? It never has all 4 wheels on the ground! *jokes*

360 doesn't fly, it lands in a prolonged & unorthadox manner.

I could always use Hydrogen instead of Helium, more lifting force.........

No you couldn't. Risk of explosion. You may as well call it the Hindenbot!

The magnet thing is tricky, the scales don't take into account the additional down force of the magnets, which does increase the robot's weight.

I think it's a neat solution, if a little sneaky.......

Well you could measure the down force. Just stick iron underneath the weighing platform.

I think it's ungallant. Using it as in 540, to stop people flipping you, enhancing your pushing ability & to resist the opposite reaction of the spinner is IMHO unsportsmanly.

Then the war of attrition will start. more down force will be added until the apparent weight of these robots are superheavyweight

**typhoon_driver** · 15th March 2011, 15:35

Helium wouldn't work, so little upforce that it's pointless.

Magnets as far as i'm concerned aren't a problem. There should possibly be a few rules writing about safety with them but I don't see a problem with their use. You can talk all you want about unfair advantages but then in my opinion having no weapon on your robot gives you an unfair advantage as you can use more of the weight of your machine for armour.

You would never be able to use more than the magnets that 540 will be using as the motors, speedos, batteries etc have to be upgraded to be able to handle the extra strain of the additional weight so no you would never get a superheavyweight type machine in the featherweight class. I say it's just being creative with the environment you are fighting in, i could equally say that a wedge running along the ground gives you an unfair advantage but that's always been accepted.

O and sticking iron under the weighing platform would do little to nothing as the magnets force is applied over a relatively short distance.

**PJ-27** · 15th March 2011, 17:08

@ Woody

I didn't disagree did I ? .........

Sorry misunderstood.

Eventually... after DM regularly trashes the oppostion... this loophole in the rules will be closed.

DM?

@ psychostorm

HindenBot! I love it.

The magnet things is interesting, but you do have a point, the magnets will add their own weight, plus the robot being heavier (due to the magnet's pull) means it'll have to be more powerful to be able to move itself around. So there are trade offs, whether these equate to not having magnets I don't know.

How about you put polar opposite magnets in your own robot that repel the others! Brain = melt.