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Unread 06-05-2014, 02:28
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cbale2000 cbale2000 is offline
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AKA: Chris Bale
FRC #5712 (Gray Matter)
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Re: VIAIR 250C-IG Compressor

Quote:
Originally Posted by jbsmithtx View Post
... 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.

Quote:
Originally Posted by AllenGregoryIV View Post
... 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.

Last edited by cbale2000 : 06-05-2014 at 02:33.