need help picking valves and tactile switches

[staplemonx]

We are in the middle of designing our pneumatics system and need a little help identifying which solenoid valves and which tactile switches to use. Does anyone have a some recommendations on which festo valves would work for this type of setup? Also has anyone used any tactile switches before? We are trying to find out what kind we should use and how we should wire them.

Thanks

[IndySam]

I don't understand all those storage tanks on the low side and feeding a cylinder through multiple valves isn't allowed.

<R74> Each commanded motion of a pneumatic cylinder or rotary actuator must be accomplished via the flow of compressed air through only one approved pneumatic valve. Plumbing the outputs from multiple valves together into the same input on a pneumatic cylinder is prohibited.

[staplemonx]

Originally Posted by IndySam

I don't understand all those storage tanks on the low side and feeding a cylinder through multiple valves isn't allowed.

<R74> Each commanded motion of a pneumatic cylinder or rotary actuator must be accomplished via the flow of compressed air through only one approved pneumatic valve. Plumbing the outputs from multiple valves together into the same input on a pneumatic cylinder is prohibited.

Ah, now I get that rule. When we were doing our tests this week we were able to get the speed we were looking for out of 3x 1/8 tubes, so that is why we laid it out with three. We thought ithat rule meant that we had to have a valve on each input to the cylinder. Thanks for that piece of feedback.

[Dad1279]

Team 358 has alot of excellent pneumatic info on their website: http://team358.org/files/pneumatic/

I highly recommend "Pneumatics Step-By-Step (for the cRIO Controller-2010 version) "

and "Pneumatics For Newbies" on their site.

[PAR_WIG1350]

Here are some hints broken up into 'chunks' for convenience. The way they are written they can read and digest individually with ease, which is recommended, but not necessary.

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~solenoids run off the digital sidecar need to be controlled indirectly, through a spike. They can be run directly off of a solenoid breakout on a solenoid module for the crio, but not directly off of the sidecars digital outputs.

~The primary regulator should be set to 60 psi.

~the secondary regulator is completely optional and should only be used if you are using less than 60 psi in any part of your system.

~The accumulator tanks work best on the 120psi side of the primary regulator (the side with the compressor).

~You don't necessarily need one tank per actuator. Sometimes you need more, sometimes less is sufficient, but since you are using multiple high volume cylinders, you might want more (see next tip before buying more).

~Would smaller, less air hungry cylinders work? Think of the forces needed and the ~180 pound force those 2" bore beasts are putting out individually (which is sufficient to lift your entire robot with just one). Wait, I remember now what you are trying to do, if you only plan on actuating these once per match than you should be fine with 1 or 2 of the smaller clippards plus the large one in your kit (or 2 large ones) if you plan on retracting them after that, add an additional tank if you are under weight. (1350 has had experience with the air demands of multiple, long stroke, 2" bore double acting cylinders). Sorry, Just saw the latest drawings and decided to edit this post again. With shorter cylinders, I would imagine omitting the second grayed-out section would still leave you with ample air supply to lift the extensions, but please don't just accept that as fact. I could be wrong. Test it!

~Limit switches might suite your needs better than tactile switches (although not necessarily) since limit switches are designed to be tripped by 'things' while tactile switches are designed to be tripped by fingers.

[staplemonx]

Alan thanks for the info that was very helpful. We are reducing the size of our cylinder and are going to get a few more spikes into the system. We also switched out the tactile sensors for vex limit switches. We also moved our air tanks into the high pressure zone. Lastly we removed the 120psi regulator.

Also the team, 385 site was very helpful.

Here is the updated layout