With official vex only parts, we can compress air “on board the robot” after the start and during the match.
Does anyone know if this would be allowed in a match, the rules say two tanks of air filled before the match, nothing said about on board air compression?
Before we go further in our design we would like a clear understanding of this concept.
Really? This is quite surprising (and very impressive, if pulled off). I would suggest you look through the game manual, find all the rules that might apply, and prove that this system doesn’t break any of those. But as far as my understanding of the rules is, this should be legal. But, teams and referees will definitely give this much more scrutiny, and you should have explanations on hand proving this is not a violation of any rule. Good luck, and good building.
Perhaps @100099j is using motors to compress pistons and then somehow feed that compressed air into the tank? That would be really cool and totally legal (in my understanding of the rules).
I am very interested in learning how this compressor works. If it truly is legal, it could be a game changer 
infinite strokes
I definitely think that it would be difficult to gauge the air pressure to make sure it doesn’t go over 100 psi.
Exactly what i was thinking… Maybe some crazy lexan and limit switch custom gauge…
Or they could make a few measurements of how much air a piston delivers and how much the tank has. And then add in temperature, number of molecules, etc. Then combine with PV = nRT 
I was thinking by measuring how much force it takes to turn the pump.
this is too much for 2:05 am
Pressure to turn the pump using a rpm guage, when rpm drops motor turns off,
Yup
We went through this idea last season and concluded the efficiency wouldn’t be high enough, all the hardware required to achieve it weighed too much and finally for safety and rule compliance reasons it could very easily be disallowed at a competition since there was no means to ensure 100psi wouldn’t be exceeded (and no a hacked together pressure switch isn’t going to convince your hardware inspector!). Just a novelty but a fun exercise for sure. All that remains is for someone to ask an official Q&A which we’ll leave to @100099j
Even if it’s ruled illegal, I would love to see some pictures/videos of it in action!
I think VEX should make a VEX air compressor to buy, and will have a rule to take up 2 motor ports…
The reason the reservoir rule exists is so teams are limited on how much air they have. Having an official air compressor would defeat the purpose of the rule.
I’m guessing 3D printed gaskets aren’t possible, at least with Vex 3D printing, but is there a way to make a seal airtight with 3D printing? If so, you could print a compressor and power it with a motor or two in Vex U. It still wouldn’t be VRC (MS/HS) legal, but it’s better than nothing.
Last year I wanted to do it, however due to <r18>
<R18> Pneumatic devices may only be charged to a maximum of 100 psi. Teams may only use a
maximum of two (2) legal VEX pneumatic air reservoirs on a Robot.
I didn’t think it was possible. This is mainly because there’s no way to track the amount of PSI during a match. With a good enough compressor, you can bypass 100 psi without knowing
All it wold take wold be a slender with rubber bands holding it in, and a limit switch. So as the air presser rises, the piston extends, even-truly pushing the switch.
Heir is a ruff drawing.
That’s a good idea, but I don’t think a referee would accept anything team-created as a means of ensuring you’re staying under the legal limit 