Why sloped ends?

[mhorowit]

The aileron spar has a reinforcement plate in it's center and it has sloped ends.
See attachment. Any idea why the ends are sloped? how critical do you think that slope is? - Mike

[Guest]

Re: Why sloped ends?

I susoect the slope follows the airfoil contour. It may be a clearance issue when the aileron swings upward as well as a leading edge fit issue.

[Dick Huish]

Re: Why sloped ends?

My guess is that if it slopes longitutinaly it is there for stress relief Dick

[mhorowit]

Re: Why sloped ends?

My guess is that if it slopes longitutinaly it is there for stress relief Dick

I could use some stress relief. - MikeH

[high time cub]

Re: Why sloped ends?

Mike,

In a word..... "elegance"

Since you're having fun working in wood, you might enjoy my friend Stephan's articles about building a Falco.

http://www.seqair.com/Hangar/Wilkinson/Wilkinson.html

Jim

[Guest]

Re: Why sloped ends?

arg... I was thinking of the top and bottom but you were asking about the inboard and outboard end, sorry, my bad, answered wrong question.

I think its a shrinkage and stress issue.

Check out ac43.13-1b chap. 1 section 1.2, that may help.

Actually keep going into the other sections in chap. 1 it comes up many times.

Dave

[Howard Wilson]

Re: Why sloped ends?

Could be a build in lightness technique. The part of the wood that has been removed probably didn't carry very much of the stress.

[mhorowit]

Re: Why sloped ends?

Could be a build in lightness technique. The part of the wood that has been removed probably didn't carry very much of the stress.

Hey Howard! Was out your way Friday - took my ribs for cleaning, alodining and priming. Talked to Dave and seemed to be a nice guy. Looking forward to working with him. thanks for the suggestion - MikeH

[flyguy]

Re: Why sloped ends?

Stress was a correct answer but it is probably better addressed as a "load spreading" device/design/technique. Don't want to go directly from reinforcement to non-reinforcement in zero length.
No doubt elegance does have something to do with it also. It would be ugly the other way.
Bet you will see similar stuff if you look in AC43-13 woodworking section.
Darryl

[high time cub]

Re: Why sloped ends?

ANC-18 and ANC-19 if you want to delve deeper into the heart (wood) of the matter.

http://www.esscoaircraft.com/product_p/16398.htm

http://www.esscoaircraft.com/product_p/16402.htm

[Howard Wilson]

Re: Why sloped ends?

Hey Howard! Was out your way Friday - took my ribs for cleaning, alodining and priming. Talked to Dave and seemed to be a nice guy. Looking forward to working with him. thanks for the suggestion - MikeH

Mike, Dave is a good guy, he did the annual on the 172 and found an AD that had been overlooked by several IA's for many years! Call me next time you are in the area, maybe we can get lunch. H

[jdoran]

Re: Why sloped ends?

Howard,

Where are you in Maryland?

[Howard Wilson]

Re: Why sloped ends?

John, I'm in New Market. 10 minutes East of Frederick. The T-craft is based up at Keymar.

[NY86]

Re: Why sloped ends?

FlyGuy is correct. The short answer is "to avoid abrupt changes in cross sectional area." Otherwise, when you flex the member it'll have a stress point right at the edge of the reinforcing plate and break there every time.

Didn't Stephan Wilkinson write about the Falco in some magazine many years back? I seem to remember following that project with envy from conception to the point he sold the plane...

[high time cub]

Re: Why sloped ends?

Hi John,

"Air and Space" http://www.seqair.com/Hangar/Wilkins...MovingDay.html

More here....scroll down. http://www.seqair.com/Hangar/Wilkinson/Wilkinson.html

Also.... http://www.amazon.com/Gold-Plated-Po.../dp/1592282563

And.... http://www.amazon.com/Man-Machine-Be.../dp/159228812X

Happy reading!

Jim