Lifting robots

[rjbarra]

There will be a lot of veteran teams that are adding the capabilty to lift Robots for the final period of the FRC 2007 competition. It might be a good idea for your robot to have a protective bottom so your robot does not get damaged being lifted by a fork lift method. Also have the capabilities of being able to go up a ramp.

[Biff]

In the robot design thread someone mentioned an inflating ramp(s). I was so taken by the idea that the possible ways to do it starting running through my head. 1) you have to be able to inflate fast 5 to 7 seconds, 2) you want to get to the 30 point hight. 3) with the power off you don't want it to settle. 4) the ramps top surface should not allow the robot(s) you are lifting to damage the air bag.
The best starting point I came up with is those inflatable beds, they take way to long to inflate normally and are to heavy as supplied but have other essential items. Or the other item is a good blower ( like out of a shop vac, normally only one stage) that can be powered by a kit motor (or two). Volume is the big issue as 0.2 lbs. of air pressure in a bag 36" x 36" x 13" will give you (36*36*.02=259Lbs) of lift. A thin tough ramp(s) attached to the sides of your bot that drop down with the bag under and a check valve (flap) to keep inflated after you lift your team mates bots. Rip stop sail material might be a good starting point for the air bag.
Not playing this year but still get to think about the game
Biff

[jskene]

The pneumatic rules typically disallow any pneumatic component not shipped with the kit. This would include a fabricated airbag.

Other than being illegal, this is a good idea.

[Rick TYler]

Rip stop sail material might be a good starting point for the air bag.

Think "Tyvek."

Not playing this year but still get to think about the game

You and me both.

I'd ask the airbag question in the official FIRST Q&A forum. It's enough unlike a "pneumatic device" that I'd want clarification.

[BobC]

Originally Posted by jskene

The pneumatic rules typically disallow any pneumatic component not shipped with the kit. This would include a fabricated airbag.

Other than being illegal, this is a good idea.

<R02> Energy used by FIRST Robotics Competition ROBOTS, (i.e., stored at the start of a match),
can only come from the following sources:
• Electrical energy derived from the onboard 12V and 7.2V batteries
• Compressed air stored in the pneumatic system, and stored at a maximum pressure of 120
PSI in no more than four Clippard Instruments tanks. This compressed air must be supplied
by the compressor included in the Kit Of Parts, and can not come from any other source.
• A change in the altitude of the ROBOT center of gravity.
• Storage achieved by deformation of ROBOT parts. Teams must be very careful when
incorporating springs or other items to store energy on their ROBOT by means of part or
material deformation. A ROBOT may be rejected at inspection if, in the judgment of the
inspector, such items are unsafe.

[Kevin Sevcik]

More to the point, FIRST has consistently ruled against these kinds of air containing devices consistently in the past. If it holds pressurized air, it's a pneumatic device. If it's a pneumatic device, it has to be in the kit or an approved extra cylinder.

[Biff]

Originally Posted by jskene

The pneumatic rules typically disallow any pneumatic component not shipped with the kit. This would include a fabricated airbag.

Other than being illegal, this is a good idea.

It's allowed if it's an off the shelf item.
Fan mechs have in the past been used to create vacuum to hold objects (balls).
If you really want to read about fighting about Pneumatics, look up the threads on stooping or holding an air cylinder in mid stroke. Simple to do with the correct off the shelf SMC valve, hard to do with the valves that come in the kit.

[team 1094]

Originally Posted by Biff

In the robot design thread someone mentioned an inflating ramp(s). I was so taken by the idea that the possible ways to do it starting running through my head. 1) you have to be able to inflate fast 5 to 7 seconds, 2) you want to get to the 30 point hight. 3) with the power off you don't want it to settle. 4) the ramps top surface should not allow the robot(s) you are lifting to damage the air bag.
The best starting point I came up with is those inflatable beds, they take way to long to inflate normally and are to heavy as supplied but have other essential items. Or the other item is a good blower ( like out of a shop vac, normally only one stage) that can be powered by a kit motor (or two). Volume is the big issue as 0.2 lbs. of air pressure in a bag 36" x 36" x 13" will give you (36*36*.02=259Lbs) of lift. A thin tough ramp(s) attached to the sides of your bot that drop down with the bag under and a check valve (flap) to keep inflated after you lift your team mates bots. Rip stop sail material might be a good starting point for the air bag.
Not playing this year but still get to think about the game
Biff

the problem i can see with your design is after the match is over all power is shut off to all robots(you could try to put your air things on a separt circuit, but i don't know if it is allowed{CHECK THE RULES}

[Biff]

The air things are simply fans and bags. As I said in the original post the pressure is less than 0.2 lbs. to get the force needed to more than lift a Robot, and a flap valve on the input tube to the bag is all you should need to hold air after the match. Fans that create vacuum have in the past been allowed as long a the power for the fan comes from a kit motor. The other thing that occurred to me was to power the fans from the main drive motors using a clutch or a dog mech that way you are not using a motor to only power the fan(s) the fan from a shop vac spins somewhere around 18 to 25 thousand RPM, so some serious gearing up is in order. The good news is it's not to hard to gut the motor part and put a pulley or two on the remains.
One example of a blower that we didn't use last year and one complete with Two Fp's driving it The one that made it to use was one Cim driving an 80 tooth pulley and then the smaller pulley on the shaft. Btw the Fp's drew about 30 amps each and the Cim ran at about 48 to 50 it didn't blow the snap action in the time of a typical match. That's why I suggested getting drive power from your main drive line.
Biff