Suction cup for grabbing boulder question

[17lbrannan]

Hello Chief Delphi,

So our team has a green FC75 piab suction cup that we were considering using to pick up boulders, and we are unsure of it's legality. We checked rule 77 and in the blue box directly below it stating that devices creating a vacuum were not subject to the pneumatic rules. However, the suction cup uses the pneumatic system for it's suction. It uses a 4mm black tube instead of the usual 1/4 in tube. If anybody could shed some more light on its legal status, or had any insight please let me know.

Thanks dudes

[dmaggio744]

While the cup itself may not be subject to the pneumatic rules, interfacing it with an FRC legal pneumatic system seems a bit interesting. Can you say exactly how your controlling it without giving away too much?

[17lbrannan]

@dmaggio

I don't fully know about how we would be controlling it. It is still in the preliminary design process, so we just want to figure out if we can use it before we continue. You can see what it looks like at http://www.pi-vacuum.com/wp-content/...-cup-FC75P.pdf

[dmaggio744]

Thanks for the link!
In my experience, pneumatic systems work by pushing air in one direction or another, causing a piston to extend or contract. While you could create a vacuum by using a complicated pneumatic system with multiple pistons, you might be better off finding a vacuum or reversible pump and replacing the motor with something frc legal.

Most pumps for air mattresses have a second hole that will act as a vacuum to aid in deflating the mattress, I'm sure you could figure out some way to replacing the motor inside a cheap one from Walmart(or any other department store)

This thread from 2013 might be of some use: http://www.chiefdelphi.com/forums/sh...d.php?t=110832

Keep me posted on your use of suction cups for this year! We never really considered vacuums, and it seems like a very interesting solution.

[17lbrannan]

Thanks man Ill keep you posted

[BoilerMentor]

Generally in the scheme of FIRST volume vacuums (Like a shop vac, motor driven rotating fan) have been more successful than pressure vacuums (air across venturi or ).

In 2008 as a student on 1741 we used replaced the motor from a conventional vacuum fan housing with a Fischer-Price motor. It generated a vacuum of about 28 inches of water. Obviously a 40" ball makes has a lot more surface area to work with than a 10" ball, but it could still potentially work. A volume vacuum is much more leak tolerant than a pressure vacuum, which is the primary advantage here.

To find components, talk to a local vacuum repair shop. Generally they'll have fan housings with burnt out motors they would be happy to get rid of. It's late in build season, so there isn't a great deal of time to get this implemented, but a 775 motor would probably do a great job in the application.

If you have any questions, let me know. I'd be happy to help.

Good Luck.