I have an initial plan for picking up the hatch panels: Suction cups on the flat parts, with a tube running through the center to let air in to detach the cup. I have two questions about this:
Suction cups aren’t considered pneumatic parts because they hold negative pressure. Also, it’d probably be easier to use a normal suction cup with a vacuum blow-off valve/generator, rather than drilling a hole in a perfectly good suction cup. However, I don’t think anyone’s tried using cups with a blow-off valve before. If the blow-off system can’t hold any pressure at all, it should be legal as a non-pneumatic device. But if the blow-off side of the valve can hold any pressure, or you’re using one of the all-in-one vacuum ejectors that are two solenoid valves, supplied with compressed air and connected to an internal vacuum generator and blowoff system, you’ll need to follow all the pneumatic rules. I’d recommend lots of Q&As and lots of documentation. I’m looking at one on Misumi that’s probably legal (and $200, ouch). There’s also vacuum generators with ejector ports that take two compressed air lines, one to generate vacuum, the other to blow-off. Those are $50, probably easier to argue they’re legal.
I happen to know of a team that used that exact type of system to pick up frisbees in 2013. A suction cup fit with a pneumatic line that was used to release frisbees. That mechanism had many problems, least of which was the pneumatic line, but I would still suggest looking at alternatives.
I’m not entirely sure what you mean. I am basically talking about using a suction grip, just like a normal suction cup, but venting air into the cup to break the suction. Initial experiments with a toilet plunger suggest that I shouldn’t need to continuously suck in air to create a vacuum. Also, we will probably be using other pneumatics if that helps. Thanks for your response,
Amicus1
Can you link to a video of that? I may not have explained clearly enough
I’m mostly saying you don’t need to have a vacuum line and a separate blow-off line to the suction cup. There’s vacuum generators that handle all that through their vacuum output port so you don’t have to modify the suction cups.
All in one electronic valve that takes one compressed air line, and two 24VDC control signals. One signal turns on the vacuum generator and sucks air out of the vacuum port, the other dumps compressed air into the vacuum port to blow off whatever you’ve grabbed.
Air-only vacuum generator with two ports for compressed air. Supply air to one side and it sucks air out of the vacuum port. Supply air to the other side and it dumps that air out of the vacuum port to blow off the part.
Once you have a seal, you don’t need much volume at all to maintain vacuum.
If you do go this route - vacuum that is - be sure to test it under dusty conditions you might encounter at competition. Things might not hold as you wish.
Pretty sure that this is the mechanism I was talking about. It seemed to work well in this video and at the beginning of competition, but it had some mechanical problems (read bent piston) and I don’t remember seeing it much towards the end of comp. The suction cup mechanism though seems to be similar to what you are talking about, with the piston adding the initial compression force and air only being pushed in to release the frisbee into the storage container.
If you use this suction cup mechanism in a simpler overall mechanism, you may be able to see good success with it. My only question is whether it’s really the simplest solution that will accomplish your problem to the degree you want it to. K.I.S.S.
That was what I was talking about, thanks.
No problem, anytime 
We really like the idea of using a suction cup design for picking up hatch covers as well. Have you considered using one of the suction cups with mechanical quick releases? In that way, you need only drive the quick release lever with whatever mechanism works best for you, be it a pneumatic cylinder, or possibly even servo.