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Unread 13-08-2014, 12:44
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Re: Pneumatic Restrictions & Improvments

Quote:
Originally Posted by FrankJ View Post
The on board relief valve will limit you to 125 psi or so. If the team is going to readjust that after inspection then they are willing to cheat in other ways as well? Typically one of the things the robot inspectors are looking at in queue is the storage & working pressures.

Since you are not limited (204 at least) in storage volume, the difference between an unregulated air source & legal source could be 15 -20 minutes in extreme cases. Personally I would prefer they limit on board storage volume, but that would be harder to inspect for.
I was for limiting on board storage in the past, but when you compare the energy density of the tanks to the batteries, it's just not a big deal in my mind.

a 44 cubic inch tank at 120 psi stores .7 KJ of energy if released adiabaticly, teams won't effectively ustilize all .7 kJ of this for various reasons (losses in the system before it even gets to cylinders, as well as not operating down to 0 psi). So let's call this .35 Kj.

I'm going to be lazy and approximate the FRC battery in the average bot as supplying 100 Amps at 10 V for 2 minutes, this is 60KJ/min for 120 KJ total.

If a team precharges 20 44 in^3 tanks... you'd have ~ 7 kJ of usable energy versus ~120 KJ.

Numbers are admittedly fudged here for quick calculation, but the trend is valid. The amount of air you can store in terms of energy is not much compared to the battery, so in the name of an even playing field in terms of energy use across teams, it really isn't a big deal.

Now, limiting storage for safety reasons is another argument....