We are looking to create an off robot pneumatics recharge pack for this season and have had a hard time finding some good examples to start with. Could CD folks post a few pics of pneumatics off robot recharge packs that they liked. Thanks!
I think because most of us thought strapping a compressor and an air tank on the back of a human was a bad idea. That slight possibility of a 100PSI rupture causing injury was a primary factor.
You should be able to find that discussion.
Before we go down this rabbit hole,
JJ, What exactly are you trying to accomplish with the project? When would this be used?
Also, bear in mind that if you are using this pack–in whatever form–to charge your tanks before matches, the way the rules were for 2015, you won’t be able to have an onboard compressor. I want to say someone even Q&A’d it.
(For practice is another story–but then you just have to consider safety and getting the air to the robot.)
R68
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.
I’d also like to point out the 2015 R70:
“Stored” air pressure on the ROBOT must be no greater than 120 psi. No stored air pressure intended for the ROBOT may be
located off-board the ROBOT.
Emphasis mine. While you could have a “pack” (read: self contained module) with the compressor, gauges, hoses and such that comprises a legal, off-robot compressor system, you may NOT have any air storage on that off-robot system.
Over the weekend we saw FRC 346 had a great air recharge pack. It had all of the things it legally needed and was in a great configuration. Let’s say is was 12"x8"x10" I did not take a photo and I should have. So I am looking for some more examples to show my kids so they can make one.
I have no idea if we are going to use it this season, but it looks like a great project for a few kids to take on.
R74 and R75 of the 2015 rules have simple diagrams showing what should be in the off-board compressor unit. There aren’t really enough components to need very much creativity to build it elegantly; just make sure that you can carry it without touching the (hot!) compressor. Some quick-disconnects for the wires (e.g. Andersons) are also in order.
Not particularly FRC legal, but if you wanted a recharge pack. Probably need to add a regulator. Are if you want to barbecue…
Will add some pics and spec’s when I get to the shop, stay tuned.
We are looking to create an grabber pneumatics (hand for this season to school kids at near area to give them chance to play with it,.
any some good examples to start with. Thanks!
OK a few photo’s as you mentioned missing the opportunity to take some.
In a re design we may add slots to the wood frame on the compressor side for improved cooling. Not that we’ve had an issue, more of a can’t hurt improvement.
You would not be able to use the pack pictured above for competition under either of these 2015 rules - no battery, no switch, and no air tanks can be off board. There may be some other nitnoids, but I stopped looking after these obvious ones.
I am also very confused by the pictured recharge pack. Not only is it not legal (must be controlled and powered by robot), but having tanks onboard the pack makes no sense to me. I am going to assume that your goal is to fill the tanks on the robot and that you started with the tanks on the pack full before connecting it to the robot. The air stored on board the pack will spread equally through out the system and drop in overall pressure. Then you would have to leave it connected with the compressor running until not only the robot was full, but also the onboard tanks. I believe that it would take an equal amount of time as without tanks to fill the robot, therefore it is unnecessary to have the tanks.
My guess would be, since it’s not controlled by the robot (once again, <R69>), and thus not limited by the pressure switch, they fill those tanks beyond 120psi. They probably use that final pressure regulator to ensure a 120psi fill into their on-board storage.
It looks like they could turn a valve and disconnect the tanks after the pressure has been equalized. We used a similar setup controlled by the robot in 2014.
Having the tanks on the recharge pack makes it against r70 as pointed out in post 8. Hope that wasn’t used during the season at a competition.
In the past, even when it wasn’t against the rules we got a hassle for offboard storage. And having a valve to seperate the tanks from the system wasn’t enough, trust wasn’t very strong that day…
If it’s not going to be used for competition, why not just get an A/C compressor that will charge much faster? Here is a 150 psi 6 gallon A/C compressor for under $130, much less than the components used for the the module shown. As I figure it, 6 gal of 150 psi air expands to about 7-1/4 gal of 120 psi air, so you can charge five quarts of on-board tank (that’s eight of the largest plastic tanks currently on the AndyMark site) to 120 psi from a full charge of the on-board tank, no more electricity needed.
Addendum: After working with the air cannon for several years, I’ve come to realize that an FRC battery is a very inefficient way of getting compressed air (especially in terms of time, but also of electricity). Unless you have rules that specify that the air must come from a compressor powered by the robot’s battery, there are several much better ways! On top of that, the regulator to get from 120 psi to 60 psi is inherently no more than 50% efficient when the tanks are full. Pneumatics are an elegant solution when you want to project a defined force, so I would be willing to put up with inefficiencies. Other than that, I’d try to find a way to use a motor more directly.
Pictures were asked for and provided.
If you can build a better mousetrap, do so.
All the “concern” is appreciated.
True, but it is not illegal to use in your shop for refilling a robot during practice.