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UP2 mains retract unevenly

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UP2 mains retract unevenly

Old 05-25-2015, 02:46 PM
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dbsonic
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Default UP2 mains retract unevenly

For those using the UP2. Do you ever have problems with the mains coming up at different times? I have the airlines for the mains on a tee and then run them to the UP2. But even so the mains don't retract at the same time. Its one after the other. It's almost though the exhaust from the one prevents the other from retracting until the system/UP2 itself has exhausted the air. If I remove the exhaust altogether on the slow side, it comes up immediately so it seems like an exhaust problem.

Are the mains not supposed to be on a tee.?
Old 05-25-2015, 03:22 PM
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invertmast
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Are the airlines the same length?
Old 05-25-2015, 03:41 PM
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Vincent
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I have been running up2 and 3 valves for many years. They go up and down together unless there is a mechanical problem with one of the retracts. Maybe one requires a little more pressure to unlock or one of the airlines going to that gear is pinched, clogged etc.
Vin...
Old 05-25-2015, 04:25 PM
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Thomas, they are not the quite the same length. It does appear there is some offset... Maybe a difference of 2 inches(slow retract on the short side). Tough to reach but I should see if that's it.

Vin, could be. But if I remove the exhaust on the slow one, it then goes up faster than the other! in that case.
Old 05-27-2015, 02:07 PM
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In my case the main issue seems to be what Vin said. One retract appears to require more pressure to unlock than the other.

Phil at Ultra Precision says that it is not uncommon and that the valve should wait and sense when all retraction is complete before closing the doors. Its seems to do this 90% of the time but I've experienced 2 instances where it did not and the cycle was messed up. In my case all gear still came down successfully so no repercussion.
Old 05-27-2015, 02:43 PM
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Vincent
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Check the gear to see if the tire or the strut is bottoming out on something like the wheel well bottom and putting pressure on the retrac lock. This will require more air pressure to release the lock and move the gear. I don't know what your setup looks like but just guessing here.
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Old 05-27-2015, 02:57 PM
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It appears to be a manufacturing flaw in the retract. The track milled in the retract frame is not smooth. Best I can tell the table was moved with a halted bit in the chuck and dinged the track in the frame. The other retract is correct and well made.
Old 05-27-2015, 03:06 PM
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I have taken a Dremel and smoothed out the locking groove on some of the Chinese gear to get them to release. Just round off the sharpe edge on the lock.
Old 05-27-2015, 03:09 PM
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Thinking the same thing. I'll give it a try just a little bit at a time. Thanks for the input.

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