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.
Quick exhaust valves. PLEASE
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. :rolleyes:
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!
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.
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).
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. :yikes:
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.
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.
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.
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.
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?
The issue with home-spun pneumatic systems like you describe is that they require a certain amount of knowledge and experience for someone to determine if they’re safe… and unfortunately many of our inspectors don’t have that knowledge or experience. By requiring specific parts, that it’s hooked up in a specific way, that it runs from the robot control system, and specific observable operational behaviors, we can ensure a system is safe without requiring inspectors to be experts. It’s the combination of known components with known behaviors and the observable behavior of the system that tells us it was hooked up correctly. With a home-spun system we don’t have known components with known behaviors controlling it, so our observations from a single run don’t tell us enough to ensure it’s safe.
I know a number of years ago my team was working on an off-season project and a couple of the mechanical members decided to “safely” power the compressor by running one of the power leads through the pressure switch and plugging it into a battery. It worked a couple of times before the pressure switch stopped working, as the switch wasn’t designed to handle that much current. Given a similar situation, a team could demonstrate proper behavior, only to have that behavior go out the window a few charges later!
Don’t you just love the English language and how it can be vague and very specific at the same time?
I don’t understand the whole issue of using an off-board compressor to store air into the robot’s system if the off board compressor can easily be connected to the robot’s control system (temporarily in place of the on-board compressor) so the the robot can control the air input for a pre-match charge. This way the on-board compressor won’t heat up because it isn’t being used pre-match.
What I’m seeing a lot of people say is that people used multiple compressors at one time to charge a system. I can see this being a bit of an isssue, but not the situation I mentioned above, because in the senario I provided there is only one compressor/air source connected to the robot’s system at any given moment.
My apologies for mis-understanding and not being clear.
What I meant was was switching between two off board compressors, to make sure none of the over heated but only using one actively at a time. While having no on board. My team had to do this due to the enormous (5gal) tank we had and we had deliberate over the “one and only one” rule.
But if a team were to have a on board and then disconnect it, and use an off board properly wired into the robot to pre-fill before a match so the on board stays cool during the match; I would think this is legal? Since air is only being provided by one compressor at a time that is wired legally.
This is legal, there was a clarification early this season, if I remember it correctly the requirement is that the compressor must be operated using robot control system.
Couple of years back I have seen teams using a off-board compressor directly plugged into battery and charging… this is illegal.
The key thing is there are only so many safety inspectors who can check all on-board and off-board pneumatic systems. It isn’t easy for these inspectors to twist and bend in every direction to access the on-board system. If teams are allowed for off-board control system (or worse no control system) and off-board compressor, now the inspectors will have to inspect these systems that may be on the cart or somewhere else. God bless them, they do a good job to keep everyone safe.
That would still be an obvious violation of R79.
If the compressed air is generated and mixed from more than a single compressor, then rule R79 is violated.