Pneumatic Restrictions & Improvments

[lynca]

In 2014 we saw a large upswing of people using pneumatic for their launching mechanism. This created quite a discussion on rules and legal restrictions for pneumatics.

If you are the GDC , How would you improve the pneumatics rules next year ?

For example.

Why are we limiting CV , tubing and port size ? (CD thread )

Why do we limit low-pressure to 60 psi compared to 70 or 80 psi ?

Are there any devices that could improve the pneumatic experience for most teams ?

[magnets]

Originally Posted by lynca

In 2014 we saw a large upswing of people using pneumatic for their launching mechanism. This created quite a discussion on rules and legal restrictions for pneumatics.

If you are the GDC , How would you improve the pneumatics rules next year ?

For example.

Why are we limiting CV , tubing and port size ? (CD thread )

Why do we limit low-pressure to 60 psi compared to 70 or 80 psi ?

Are there any devices that could improve the pneumatic experience for most teams ?

First of all, pneumatics restrictions were lessened by a lot this year. The CV of the valve restriction was removed.

The reason the GDC limits CV is for safety. If we had unlimited CV, and someone were to put their head against a medium to large size pneumatic cylinder, and it is accidentally actuated, the person would die.

[sanddrag]

Quick exhaust valves. PLEASE

[Mk.32]

Originally Posted by magnets

First of all, pneumatics restrictions were lessened by a lot this year. The CV of the valve restriction was removed.

The reason the GDC limits CV is for safety. If we had unlimited CV, and someone were to put their head against a medium to large size pneumatic cylinder, and it is accidentally actuated, the person would die.

Even with our current systems that could happen, 2in bore cylinder with 60PSI behind it is a lot of force. Also some spring punchers were just insane in amount of stored energy.

Basically the hose (1/4) and the 1/8 NPT rule limits the "power available".

Personally I want to be able to use a 3000PSI CF paintball tank/regulator so I never have to charge air at a competition but I don't think that's happening anytime soon.

[apples000]

Originally Posted by magnets

First of all, pneumatics restrictions were lessened by a lot this year. The CV of the valve restriction was removed.

The reason the GDC limits CV is for safety. If we had unlimited CV, and someone were to put their head against a medium to large size pneumatic cylinder, and it is accidentally actuated, the person would die.

Very true.

This year, we were playing around with a pneumatic launcher, and we wanted to try it with shop air. Strangely, no air was coming from the valve, and after closing all the other valves in the room (it shuts off the compressor if it detects a leak) so I went to go to the maintenance room to check on the big compressor. It turns out the room's dump valve had a faulty contact, and when I opened up the electrical panel, the valve opened, pressurizing the cylinder very, very quickly. The cylinder and its bracket went flying across the table, both fittings were torn/snapped off. It left a sizeable dent in the sheet steel counter, and chipped off part of our CNC's safety shield!

[DampRobot]

Let us charge with offboard air compressors, even if we have one onboard.

If it's made legal for everyone, it's no longer a competitive advantage, and there are ways to let it happen safely. I'd argue it's much safer to go into the match with a cool compressor than a hot one which can melt tubing or drag on battery voltage.

[Mk.32]

Originally Posted by DampRobot

Let us charge with offboard air compressors, even if we have one onboard.

If it's made legal for everyone, it's no longer a competitive advantage, and there are ways to let it happen safely. I'd argue it's much safer to go into the match with a cool compressor than a hot one which can melt tubing or drag on battery voltage.

As a robot 2014 inspector, this can be legal. You just have to power it from the robot. With either an 2nd spike or just unplugging the off board temporary. I know 987 actually had two off board compressors they switch between to make sure they never over heated.

Now I understand you probably mean just plugged in a off board into a battery, or using a shop air compressor. But safety concerns I would guess, have first to ban them and we have no power over that. Again rules many change in 2015, but doubt they would change this one.

[Gregor]

Originally Posted by Mk.32

As a robot 2014 inspector, this can be legal. You just have to power it from the robot. With either an 2nd spike or just unplugging the off board temporary. I know 987 actually had two off board compressors they switch between to make sure they never over heated.

R79 is pretty clear stating that you cannot. "One and only one compressor."

Originally Posted by 2014 Manual

R79
Compressed air on the ROBOT must be provided by one and only one compressor. Compressor specifications may not exceed nominal 12VDC, 1.05 cfm flow rate.

[Mk.32]

Originally Posted by Gregor

R79 is pretty clear stating that you cannot. "One and only one compressor."

We had this debate .... and I think it was on QA too, one and one compressor = one running at a time. So you can have two in the pits/around, but you can't use them both at the same time (aka to charge air faster).

[chrisfl]

We had a pneumatic catapult. I found a way to actuate a 2in bore, 10in stroke at the speed of a 3/4 in bore, 4in stroke. So, staying within the regulations, we had the strength of a 2in bore with the speed of a small, 3/4in bore.

[Jon Stratis]

Originally Posted by Mk.32

We had this debate .... and I think it was on QA too, one and one compressor = one running at a time. So you can have two in the pits/around, but you can't use them both at the same time (aka to charge air faster).

I just checked, it wasn't specifically asked on the Q&A this past year. Regardless, R79 is very clear - your robot can only have one source of compressed air. Filling it with an off board compressor then using a different on board compressor during the match is two sources. If you dump pressure before the match, your fine... And as an LRI, that's what I'll do if I see a team charging with an off board compressor while having one on board.

[JB987]

We didn't have an on board compressor on our robot. As stated in previous post, we had two off board compressors and only used ONE at any given time.

[DampRobot]

Originally Posted by Mk.32

As a robot 2014 inspector, this can be legal. You just have to power it from the robot. With either an 2nd spike or just unplugging the off board temporary. I know 987 actually had two off board compressors they switch between to make sure they never over heated.

Now I understand you probably mean just plugged in a off board into a battery, or using a shop air compressor. But safety concerns I would guess, have first to ban them and we have no power over that. Again rules many change in 2015, but doubt they would change this one.

I've seen people on these forums and elsewhere explicitly say that you can only have one compressor charging the robot's tanks, which means no off board compressors if you have an onboard one. Not that you're incorrect, but there's definitely a lot of misinformation out there about this.

Yes, that's what I mean. Having to enable your robot with the DS just to charge the tanks is a huge PITA. As long as you can demonstrate that your off board control system will shut off automatically at 120 PSI, and had an emergency pressure relief valve, I don't see how it's a safety concern. In any case, it's exactly how the inspectors determine that the regular onboard pneumatic compressor is safe.

[headlight]

Originally Posted by sanddrag

Quick exhaust valves. PLEASE

Quick exhaust valves can be approximated by using a 2 port solenoid valve at the cylinder and controlling it through software to provide an additional dump path. It would be way easier if we could just use quick exhaust fittings.

I would like to be able to use mufflers. Please. It is a small purely aesthetic change but high flow vent caps on the solenoid manifolds ensure that nothing gets inside. And a high flow muffler on the manual pressure release vent plug just helps keep sound down and makes sure there isn't a blast of air blowing stuff around whenever you dump pressure.

If would be nice if the pneumatic rules were just slightly more clarified and consistent. Things like ball valves, can they be used or not? or can they only be used as the main pressure dump?

There is also an entire world of pneumatic logic that hasn't been particularly capitalized on.

[FrankJ]

I would eliminate plastic storage tanks completely. I would consider requiring that storage tanks be mounted to avoid damage by contact with the field or other robots, but that would be a hard rule to word.

One issue with shop compressors is that almost all the venues are power limited. You don't have enough power in the pits to run 30-60 compressors at the same time. A side effect of limited the compressor capacity is the it limits the practical amount of stored air on the robot. Maybe limit the stored air volume & open up off robot compressor sizes?