[Captain_John]

Tell me, I am currently backriveting my stiffies and got to wondering why finish the trailing edge bend now, rather than to wait until after the top spar to skin rivets are done?

Seems that there would be more room to buck if we waited until the top rivets were set before completing the bend.

Once it is bent, then install the outside ribs.

Am I missing something? Would this work?

CJ

 

[joeboisselle]

John,
I think if you had the spar riveted to the top, it wouldn't allow you to get the full bend required, the spar would simply be in the way. In chapter 6 of the construction manual, there should be a diagram on how control serfaces should look after being bent. It's Fig 6.17 in the -4 manual. ~Joe

 

[LettersFromFlyoverCountry]

I use the Orndorff method. After you put the thing in the bending brake (or break as the case may be),you have to measure it against something. Being able to place the spar in there lets you see how close you are to the proper bend.

My guess is -- and it's only a guess-- that if you tried to bend after doing the spar rivets, you'd end up with a nice big sag in the middle there. Not to mention you'd be putting some forward pressure on those stiffeners and possibly bending them, and that would have negative flight characteristics, I would think..

 

[Captain_John]

Hmmmm, still thinking this one out.

In the past, I have done my my other control surfaces in a similar way. I use a brake which is slightly different than the one in the plans and in George's videos.

Mine (actually my friend's) uses threaded rods to do the compressing and pinches the trailing edge quite accurately with good precision and strength. That being said, I normally cleco the front spar in place so that it will keep the whole kaboodle true and it hasn't failed me yet. Nor have the stiffies bent under the pressure.

Sooooo, I am still thinking I will be okay. Maybe I will try one and see how it goes?

Thanks guys!

CJ