Flap adjustments

[Craig Ellison]

I mounted my left flap and found a problem not covered by what I found so far searching the forum threads. What I've got going is Im unable to adjust the flap to full up allignment with the aileron. I've corrected the interference with the leading edge of the flap and -4 mounting bold at the wing root as discussed in a thread back in Jan. 2022.
The flap pushrod mechanism is on its stops with the springs mounted. I've used up all the travel in the rod end bearing. It just seems like the pushrod is too long? If anyone has any suggestions I'd appreciate them.

[Bcone1381]

The ailerons have adjustable pushrods. They can be adjusted so the aileron matches the flap.

If the flap pushrod is exessively short, the front edge of the flap contacts the spar. That is not ideal, and could cause damage over time. I suspect the Industry Best Practice is to have the flap as far up as it will go without touching the spar. As far as I know your photo might show your flap in exactly that position! Full up Flap position effects rigging, so I rigged mine so they are identical to each other and up as far as they will go.

So, what you have is ailerons that are slighty reflexed. I reflexed mine on my Patrol. Reports say reflexing them results in less adverse aileron yaw. I saw a increase in cruise speed of about 4 kts after I reflexed mind. I think if we could get them to go up further we could improve cruise speed a bit. So if it flies hands off, and the ailerons are reflexed, and your not curious and don't want to experiment and tinker I would hesitate to change anything.

[Craig Ellison]

Hi Brooks, I get the aileron reflex but in my photo/case, the aileron is in alignment with the wing tip and my flap lower surface is not in alignment with the wing lower surface . Neither is it's leading edge close to contacting the wing spar. I would expect before doing any adjustments alike reflexing the ailerons you should be able to have the wing in alignment with the aileron at the wingtip, aileron and flap in alignment where they meet and the flap lower surface in alignment with the wing lower surface. What am I missing?

[jaredyates]

Something definitely isn't right Craig and I'm sure it's frustrating! The flap pushrod length sounds like a great place to start. Plans page 12 is drawn to 1/2 scale. Can you measure the depicted pushrod length there and compare it to your rod? Also, there is a "rubber bumper" depicted in the plans on the side view of the mechanism, is that where your up-travel is being limited? If so, I don't know what else it could be other than the pushrod length?

[Bcone1381]

Hi Brooks, I get the aileron reflex but in my photo/case, the aileron is in alignment with the wing tip and my flap lower surface is not in alignment with the wing lower surface . Neither is it's leading edge close to contacting the wing spar. I would expect before doing any adjustments alike reflexing the ailerons you should be able to have the wing in alignment with the aileron at the wingtip, aileron and flap in alignment where they meet and the flap lower surface in alignment with the wing lower surface. What am I missing?

I read what Jared wrote. I agree with Jared's point about the flap pushrod.

With that being said, It seems like you want to know how to set the flight controls on the wing to the neutral position. You need to know what is truly neutral. I would not trust your wingtip. But its bonus point if they all line up perfectly.

This is my position and understanding....Please anyone out there, correct me if I am off in my understanding.

The Datum for control surfaces being set to neutral is the Master Rib Form Block. A jig is made from the master rib form block to align the flap and aileron. If the flight control surfaces are set in accordance with that and they don't line up with the wing tip, the wingtip can be adjusted......slice the trailing edge of the wingtip, re-align it to the desired position, then repair the slice with some epoxy - cotton flox mixture. (At that point I flew, and then reflexed my ailerons, so they dont line up with the my wingtip anymore.....Oh well. I have an efficiency gain this way.)

[svyolo]

Concur with the wingtip. It is a variable. Not a fixed value.

[Craig Ellison]

Thanks everyone for your thoughts , ideas and helpful inputs. However I must confess to the problem being operator error. After verifying that my pushrod was the proper length with Vergil at Bearhawk he had me shoot him some pictures of my flap set-up and mechanism . He pointed out my problem right off. I had placed a bolt where there wasn't supposed to be one(through the spring attach points) Not sure where I got the idea for it but I did it twice. Once on each wing. Anyhow when removed full travel was restored and I was able to rig the flaps properly .