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Unread 26-02-2016, 08:54
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,763
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Re: Al's 2016 Inspection Thread

OK, time for part 2 for those of you at your first event this weekend.
1. Pneumatics. Not much has changed here from previous years although there are a number of new devices that people will be using. Please remember that all pneumatic parts must be COTS in an unmodified state (except certain exclusions listed in R76). That means no painting!
2. You may not make your own pneumatic parts. That means you may not make an extendable arm using pressure inside a PVC pipe. While it maight be cool, it does not meet the rules.
3. One and only one compressor under RoboRio control. I know you think you have ways around this rule because "air is air". There is no way around this rule. The compressor can be on the robot or it can be off the robot. You can't charge your robot with one compressor and then have another compressor on the robot for the match. No shop compressors charging the system, no exceptions. No FRC legal compressor being run directly from a robot battery while you are in the queue to pre-charge your robot. No larger volume compressor being run from a car battery.
4. The tubing you use must be 0.160" maximum inside diameter. This is not a safety item, this is part of the restriction on max available power. Inspectors are being trained on how to recognize the larger tubing.
5. If you use pneumatics there are certain items that must be present. One of those is a Nason pressure switch, P/N SM-2B-115R/443. No others are allowed and this must not be modified in any way. (They aren't adjustable anyway)
6. When using pneumatics, you must have a calibrated Pressure relief valve connected via legal rigid fittings (e.g. brass, nylon, etc.). A calibrated valve will release air when the system stored pressure is above ~125 psi. These are very easy to calibrate, it requires two wrenches and an alligator clip. Loosen the locking ring on the valve (that is the little hex nut closest to the threaded portion of the valve). Short the pressure switch terminals with the clip and enable the robot. The compressor will run continuously. There is a small hole at the top of the valve. When system pressure reaches 125 psi, some air should be released from the small hole. If no air is present, turn the top hex fitting counter clockwise until air is released. If air is released at less than 125 psi, then turn the hex fitting clockwise to stop the release of air at less than 125 psi. When calibrated, hold the top hex fitting and tighten the locking nut. This is not a precise or repeatable calibration. A correctly calibrated valve will release air between 125 and 130 psi on a repeatable basis.
7. No White Clippard tanks P/N: AVT-PP-41). If you found tanks in your robot inventory and don't know if they are these tanks, just believe they are and get rid of them. The explosion hazard is well documented.
8. "Three way valves" are now legal. these are typically known as one way valves in that air moves in one direction and when released, the pressure flows through a third port to atmosphere.
9. Compressors get hot.Do not place wiring near the compressor be careful to keep pneumatic tubing away from the hot parts as well. Tubing will swell and then fail (with a loud pop) when heated and pressurized.
10. Don't modify pneumatic parts. I am restating this so you don't paint them, obscure part numbers, make scratches, dents or drill into them. You may not drill "lightening" holes in any pneumatic part. Do not drill out and tap cylinders to accept larger fittings. Do not add mounting holes and do not try to modify manifolds to get one more output port.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.
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