Intermittent Flaps
 

I have the Van's flap actuator along with the Show Planes flap positioning system in my -10. No Vertical Power. They worked great together for the first 10 hours of Phase 1 but then the flap system started working intermittently. The control box is in the tunnel by the actuator. The system never fails on the ground, only in the air. The flaps will usually start working again when I am below 80 knots on final. Almost makes me believe that pitot pressure has some effect on the system but I know it does not! I read up on the actuator and decided to remove the flap motor and check for grease. It was fine and had no grease in it. I broke a brush on re-assembly so I went ahead and ordered a new brush set along with a new motor, but I am now wondering if the control box is the culprit and heat in the tunnel is causing it to fail intermittently. The new motor should arrive today or tomorrow but I am looking for suggestions because the more I think about it the more I believe the motor itself is not the problem. Thanks!

I just started having problems with my flap positioning system, but mine started giving trouble after 300 hours. The difference in my issue though is that I can still operate the flaps by holding down the switch. I'll be pulling my tunnel cover and investigating soon.

I think most everyone puts the position system box in the tunnel (I did at least) and perhaps heat is an issue, however maybe you had a bad unit from the get go. It isnt common at least that I've heard of that they go belly up as quick as you have experienced.

Finally I think I can help. Brian at least.
 

On my show planes set up the holes that guide the rod with the notches in it wore. This allowed the notched rod to flex and move such that the sensor in the box "detected" a notch where there was not one and therefore the flaps would stop immediately on releasing switch. Only happened if there was a flight load on the flaps. Tweaked it and added some washers to help disallow rotation of the actuator rod and now they work again. About 6 months out now.

Guys I had the same problem. Fixed it with washer and some other adjustments.
It worked for a while then I designed this spacer. So far so good. I have 1 or 2
extras contact me if interested.





Geoff

UPDATE:
 

I replaced the motor on the actuator and also took more time re-installing the flap positioner. I think I may have originally had the postioner clamps installed too far down the actuator and the rod was hitting the motor and flexing when the actuator was fully retracted. Working fine now. Thanks!