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Old 10-14-2012, 11:15 PM #1
ColtonP
 
 
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DM11 Velocity Creeping Down

Has anyone had an issue with their velocity creeping down during a practice? I chrono'd in at 290 +/-5 at the beginning of the day. A couple hours later I noticed it was at 250. After resetting the regs and trying a few things I re-chrono'd at 290. Within the hour it was back down to 270.

I was shooting a fair amount of paint. The temperature got slightly warmer but you would think that would make my velocity go up instead. Is it possible for the LPR screw to back itself out?

Curious if anyone has had this issue?
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Old 10-15-2012, 06:16 AM #2
jojo750
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have you serviced the regs recently?
i would start there.
and its not a lpr issue (i dont believe).
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Old 10-15-2012, 08:12 AM #3
CrazyHarry
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My first thought was that it's the high pressure reg as well, but if that doesn't work, I would also try to figure out what the pressure output from your tank is doing. Get an old ASA or something, slap a gauge on it, and use it as a reg tester. Some of the crappier tank regs don't do a very good job of regulating the tank pressure when it starts to depressurize. The Hyper 3 reg on your DM is pretty good though, and should compensate very well for changes in pressure... which is why I think it's more likely to be the HPR needing to be rebuilt.
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Old 10-15-2012, 10:03 AM #4
speedy2k4
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Air into the reg > air out of the reg. So a leak within the reg would cause pressure and velocity to creep.

A leak between the reg and bolt would cause your tank to empty, but the reg would allow more air through to maintain the same pressure.

It is possible for a seat retainer/adjuster to back out, but they have o-rings on them which generally prevent it.

If this has only happened at a single practice, I'd blame the paint itself or changing conditions. Humidity affects paint size more than temperature and not every bag of paint is the same (especially practice grade paint)
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Old 11-12-2012, 09:39 AM #5
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Did you have any chops during practice? If you did, the paint fill could have been causing excess friction. Just like when you use a different lube at a constant hpr setting, a very viscous lube will cycle at higher fps, while a thicker lube will cycle at a lower fps
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