VIAIR 250C-IG Compressor

[cbale2000]

Originally Posted by jbsmithtx

... So my $.02, we should be required to use x - amount of metal tubing after the compressor so that we can better circumvent problems for teams like us that never got around to adding a fan until later...

I don't think that adding a requirement like this is needed since the problem does not necessarily affect all legal compressors, or for that matter, even all usages of the compressor in question (since a compressor on a robot with minimal pneumatic usage is unlikely to get very hot. It might certainly be a good thing to add to a recommended practices section of the manual or elsewhere though.

Originally Posted by AllenGregoryIV

... Second that if you use the compressor as it's properly supposed to be used a <10% duty cycle then I highly doubt you will have that problem. We only have that problem during long practice sessions never during a match.

This depends heavily on how frequently pneumatic actuators are used on any given robot.

For example, last year we could dump our entire system down to about 70PSI from a full charge with a single volley of Frisbees (a fairly large pneumatic actuator inserted disks into our shooter), we also used pneumatics on our 10pt climber, meaning our compressor was basically running constantly throughout the entire match, even up to the last moments. After the match it would get so hot you could burn yourself on it.
By comparison, this year we only used pneumatics to shift drive gears and to actuate the collector (which was not used nearly as frequently and had smaller bore cylinders). We probably didn't even need a fan, but we added one nonetheless to be safe and because the weight cost and mounting difficulty was minimal.

Now granted one could argue these issues are a byproduct of designing a robot that relies too heavily on pneumatic actuators, and that's certainly a fair argument, but I doubt you will see the problem going away anytime soon regardless. IMO the Viar 90C compressors are rated far under the needs of the average FRC team and running it at the recommended duty cycle is simply impractical for robots that have a pneumatic systems that use a lot of air.

[Al Skierkiewicz]

Everyone,
The heat comes primarily from the compression of gases. With the smaller compressors, there is less thermal mass to sink the heat produced. Even the old Thomas compressor would get hot after a while. In the case of the newest Viair compressor being discussed, the manufacturer requires the use of the supplied stainless steel reinforced hose and supplies it with the compressor. That part is what the Q&A supports. Some teams did try using metal tubing on their robot this year. Until further notice and/or change of rules, copper tubing remains an illegal pneumatic part. There is no way for teams or inspectors to know that the copper is rated for 125 psi or that it is even rated for gas pressures above 10 psi.

[ArtemusMaximus]

Well, this thread turned out to be a lot more helpful than I thought it would be.
I appreciate everyones input.

[AllenGregoryIV]

Originally Posted by cbale2000

This depends heavily on how frequently pneumatic actuators are used on any given robot.

My statement was to show that it shouldn't be a requirement not that it's not possible to do that on a robot. You could the run compressor for 2.5 mins straight and after a few times blow the hose. What I was saying is there shouldn't be a requirement since many teams will never run into that problem.

[cbale2000]

Originally Posted by AllenGregoryIV

My statement was to show that it shouldn't be a requirement not that it's not possible to do that on a robot. You could the run compressor for 2.5 mins straight and after a few times blow the hose. What I was saying is there shouldn't be a requirement since many teams will never run into that problem.

I see, I must have misread your comment.