Robart retract problem
04-01-2009, 11:05 PM
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Robart retract problem
I have a top flite P-39 Aircobra equipped with the appropriate Robart tri-gear retracts. I also got creative and installed gear doors on the nose wheel. I used the Robart gear door cylinder and the #164 air switch that is operated when the nose wheel retracts. Basically, the nose wheel depresses the switch and then air is applied to the retract cylinder that closes the gear doors. Here is my problem: When I pump up the air cylinder (100lbs) and retract the gear the air tank purges out the main switch air hole. I have checked all the airline conectivity and it appears to all be connected correctly. The problem is serious since once the gear retracts and the air purges I cannot lower the landing gear. There is something systemically wrong with my installation but I can't identify the cause of the problem.
Can anyone help?
Sledge_78
Can anyone help?
Sledge_78
04-02-2009, 02:45 PM
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RE: Robart retract problem
Aerowoof,
Yes I agree 100% no air should be purging. But I can't identify why it is emiiting out the retract side of the valve vent.
One guess I have is that the other air valve/switch that is activated by the nose wheel contacting it may not be staying closed due to the nose wheeel not establishing a "locked" position when retracted. I am starting to dream of possible causes in my sleep. This cannot be that complicated.
Sledge_78
Yes I agree 100% no air should be purging. But I can't identify why it is emiiting out the retract side of the valve vent.
One guess I have is that the other air valve/switch that is activated by the nose wheel contacting it may not be staying closed due to the nose wheeel not establishing a "locked" position when retracted. I am starting to dream of possible causes in my sleep. This cannot be that complicated.
Sledge_78
04-02-2009, 06:12 PM
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RE: Robart retract problem
Not sure exactly what the switch is like, but it may hooked up and operating backwards. I have seen that with the "toggle" style switch used on Spring Air retracts.
04-05-2009, 09:17 PM
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RE: Robart retract problem
TLH101,
Well, I may have resolved the problem. I had noticed that the nose wheel when retracted did not actually "retract and lock" into position. The wheel was touching the fuselage floor and not letting the retact gear get into the locked position. I put a amaller nose wheel on and the gear retracted further and now locks in the "up" position. Once that was done, the air stopped purging out the valve. Gee, so simple but so hard to detect.
Sledge_78
Well, I may have resolved the problem. I had noticed that the nose wheel when retracted did not actually "retract and lock" into position. The wheel was touching the fuselage floor and not letting the retact gear get into the locked position. I put a amaller nose wheel on and the gear retracted further and now locks in the "up" position. Once that was done, the air stopped purging out the valve. Gee, so simple but so hard to detect.
Sledge_78
