pic: ~850 PSI Robot

[Jnadke]

For people lacking knowledge in physics, here's what this picture is saying:

Let's assume STP conditions, so the air pressure outside is 14.7PSI. Now, I'm also assuming that plate is 1 square foot. This is 144 square inches. Lastly, I'm assuming the table weigh 50lbs.

144 ( 14.7PSI - X ) = 50 lbs
X = 14.3PSI

All this picture says is that they are providing enough suction to reduce the pressure between the plate and the table to less than 14.3PSI. Nothing more, nothing less.

I'm not trying to bash your team or anything, all I'm saying is you're running the wrong test. Robots aren't going to lift upward, they'll push sideways. It doesn't matter if your robot can suck all the air out until it is a near-perfect vacuum, if your plate is just aluminum making contact with the polyethylene, with a coefficient of 0.1, any robot with 120lbs of torque can push you off the ramp. Now, if you had, say, rubber with a coefficient of friction of 2, and you created a vacuum, it would take a metric ton of lateral force to push you off. Big difference.

Unfortunately this isn't possible because the rubber would fracture long before a metic ton of lateral force was imposed on your robot.


I'm very impressed by the mechanism itself though. It looks very well engineered. What size cylinder are you using to suck the air out? Also, did you use a motor to actuate the cylinder or did you use another cylinder to do it? It seems to me that using another cylinder (in combination with the compressor) would allow you to suck out a far greater volume of air. Although it would weigh more, it would probabaly be less complex because you'd only have to draw the cylinder once to remove a sufficient volume of air.

Did you hook up a pressure guage to determine how much air it is sucking out?