B Model Flap Question

Discussion for builders, pilots, owners, and those interested in building or owning a second generation Sonex or Waiex.

Re: B Model Flap Question

Postby pfhoeycfi » Tue Jul 26, 2022 12:35 pm

pappas wrote:Peter,
I don't remember the distance that I moved the flap hinge aft of the lower rear wing spar. I do remember that the spec is in the plans and I set it to the plan measurement. It made all the difference.


Ok thanks. I did a calc and moving the hinge back about 1/32" should do the trick...
Peter Hoey
SEL Pvt, Comm Glider, CFIG, Pawnee & L19 Towpilot
Philadelphia Glider Council
Sonex B SNB0021, N561PH, Taildragger, Aerovee Turbo, MGL MX1, First flight Dec 18, 2022
Also built Sonerai IIL N86PH
pfhoeycfi
 
Posts: 384
Joined: Wed Jun 28, 2017 3:45 pm

Re: B Model Flap Question

Postby pfhoeycfi » Fri Aug 05, 2022 4:44 pm

Spaceman wrote:Gotcha, thanks for the info gents. Yeah I try not to excessively run the motor once it hits its stop, but when I was popping fuses it would pop instantaneously... so like the only way to not pop it was to stop short, which I don't think would be practical for flight haha! Now that I have the 7.5a fuse in it seems to be working fine; I think I will stick with that. Yeah 10a seemed like a bit much to me, and if I was just brute forcing the flaps to the top of their travel anyway that didn't really seem like the right answer.

The vertical power setup sounds awesome. Mine isn't anything as fancy as that, but I put a position sensor on the actuator so I can see on my G3X screen where the flaps are at least. I still have to manually control the switch.

Lou, the 2 on the level at the start of the video is 0.2 degrees... I zeroed it on the flap but it went from 0.0 to 0.2 when I sat in the seat. So I guess I have 26.9 degrees of travel really!

I did some more messing around today and also rigged the left flap. Oddly the left flap only travels about 25 degrees even though everything is the same between the two of them as far as I can tell. I'm not sure if 2 degrees difference with full flaps will be noticeable in flight. I guess I'll find out! In the C-130 if the flaps break and go asymmetric we don't get any notice until they hit 7 degrees difference, and that's not too dramatic. Probably not a valid comparison though haha

Anyway, I investigated more why I can't get my flaps in exactly the right 'up' position. As far as I can tell they're each about 0.3 degrees down from where they're supposed to be. I might try filing a tiny bit off the upper trailing edge of the wing to make some clearance, but I think I'll save it for later. I also found it pretty tricky and inconsistent to measure anyway, so I might just be measuring it poorly.

For reference, on the ground my upper longerons are at 8.4 degrees, and the top of the flaps are at 20.0 degrees when all the way up. So relative to the plane, the top surface of the flaps slope downward at 11.6 degrees. Maybe they should be 12? That's a heck of a lot easier to measure in my opinion!!


That's interesting I came up with exactly the same just less than 27 on the right 25 on the left. I also move the flap hinge back to try and get more up but then you lose the 2 59/64 dimension specified. At some point its close enough...
Peter Hoey
SEL Pvt, Comm Glider, CFIG, Pawnee & L19 Towpilot
Philadelphia Glider Council
Sonex B SNB0021, N561PH, Taildragger, Aerovee Turbo, MGL MX1, First flight Dec 18, 2022
Also built Sonerai IIL N86PH
pfhoeycfi
 
Posts: 384
Joined: Wed Jun 28, 2017 3:45 pm

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