First Time Pneumatics

[SuperBK]

Hi. Using pneumatics for the first time.
Question 1. How practical is it to just have tanks and not carry the compressor around? I know it depends on how much pneumatic motion you have, but given past competitions, has that proved practical?
Question 2. If the compressor is not on board the robot, I understand that it has to still be powered and controlled by the robot. How do you connect / disconnect the air?. Can a "quick coupling" type connector be used?
Question 3. According to <R103>, the wires from the Nason pressure switch must be connected to a digital input on the robot controller, and then the robot controller must control a spike with a relay output to turn off the compressor. Why won't they just let us put the pressure switch in series with the control signal for the spike and not have to worry about the controller turning it off? The software is no big deal, but I'm thinking about when the controller is being programmed, or freezes up, etc.
Thanks
Brian

[Peter Matteson]

1. If you are using a small volume of air it is reasonable to use just the storage tanks. If you know how frequently you will actuate the pistons you can calculate the air volume and storage pressure necessary using the ideal gas law (P1)(V1)=(P2)(V2)

2. Use one of the pnuematic fittings prvided and charge through the vent valve. This is pretty much the only legal way because of the restrictions pnuematic parts. A quick connect won't pass inspection if it didn't come in the kit.

3. It's been argued frequently and it comes down to this is the way FIRST wants it done. Also I don't believe the PS is rated for the current.

[Richard Wallace]

Originally Posted by Peter Matteson

3. It's been argued frequently and it comes down to this is the way FIRST wants it done. Also I don't believe the PS is rated for the current.

Look here for the Nason model SM pressure switch ratings. Looks like the switch is rated for 5A, so it appears that SuperBK's suggestion (which many others have made before) would work. But as has already been pointed out, the rules that cover pneumatics connections for FRC robots are very clear. I guess that FIRST requires direct connection of the SM pressure switch to a RC digital input in order to simplify inspection -- it makes the wiring easier to trace. It also helps prevent a potentially dangerous connection of the pressure switch in series between one of the the compressor electrical leads and the Spike relay.

[nickcvet89]

Originally Posted by SuperBK

Hi. Using pneumatics for the first time.
Question 1. How practical is it to just have tanks and not carry the compressor around? I know it depends on how much pneumatic motion you have, but given past competitions, has that proved practical?
Question 2. If the compressor is not on board the robot, I understand that it has to still be powered and controlled by the robot. How do you connect / disconnect the air?. Can a "quick coupling" type connector be used?
Question 3. According to <R103>, the wires from the Nason pressure switch must be connected to a digital input on the robot controller, and then the robot controller must control a spike with a relay output to turn off the compressor. Why won't they just let us put the pressure switch in series with the control signal for the spike and not have to worry about the controller turning it off? The software is no big deal, but I'm thinking about when the controller is being programmed, or freezes up, etc.
Thanks
Brian

It is ideal to have the compressor on the robot due to the tanks, because they do not store that much air. If you arent using that much air then I would go with just the tanks.

[EricH]

Originally Posted by nickcvet89

It is ideal to have the compressor on the robot due to the tanks, because they do not store that much air. If you arent using that much air then I would go with just the tanks.

Keep in mind, O veteran, that storage capacity is now FOUR tanks instead of two.

Then again, what is the air being used for? Shifting? No problem. Ramp deploying only? No problem. Actuator for tube gripper? Might be a problem. Combination of above? You need onboard compressor.

[whytheheckme]

We have decided to put the compressor on board this year. We have 4 solenoids that are in use to simply pick up and drop tubes. This requires an air compressor.

Maybe we should start a poll; How many teams will have a compressor on board. This would not be useful in any way other than seeing the statistics. However it would be interesting to see how many teams have a tube grabber design that use pneumos...

Jacob

[carbuff]

does any one know when they are coming