Flaperon asymetry

[jonstark]

When checking control travel or throws on the Model IV flapperons do you find that the throws don’t match from side to side?

I went back thru the rigging today with a fine tooth comb. I found that the flap crossover tube rubs on the large elevator push rod when the elevator is full nose down. I don’t think there’d ever be a situation where you’d be flying like that but the interference just barely inhibited getting the proper 19-20 degree initial setting of the flap interface. I got only 18.5 before the crossover tube contacted the elevator push rod.

The right flapperon doesn’t have as much trailing edge up travel as the left. The right actuating arm gets towards the top of it’s arc where it doesn’t move the flapperon as much as in the middle of it’s arc. The left never reaches the same height in it’s arc so travel of the lh flapperon is more linear.

Suggestions?

Thx,
Jon

[efwd]

Mind you, I have not rigged my flapperons on my SS7 yet but just hooking them up and moving through their travel I believe mine do the very same thing.
Eddie

[t j]

Here's a three page article on flaperon rigging from an old "Kitfox Times" magazine. I scanned the pages as Jpgs so hard to read on the computer. Print them out and they will be easy to read and see the diagram.


This article helped me a lot when I was rigging my model four 24 years ago.

[jonstark]

Thanks Tom!
As hard as I looked at this thing this was the only thing I could figure. I just knew I hadn't messed it up that bad.

jon

DAR coming on Thursday.

[David47]

This is a welcome article. Thanks TJ. This will help when I come to rig my flaperons .....

[t j]

This diagram shows how the different clocked angles of 32 degrees on the right and and 26 degrees on the left flaperon control horns results in equal flaperon movement. I penciled in the lines and wrote the degrees (29) on the diagram in my manual to satisfy myself that it actually works to give each side an equal clocked angle of 29 degrees. It has to do with the fact that the flaperon horn pivot points on the mixer are located 3 degrees behind the control rod pivot points on the flaperon horns when the fuselage is level.

[efwd]

This stuff is pretty interesting. Thanks for posting
Eddie