Drill the rear wing spar

[Weefle]

Folks, I mounted my wings today for the first time ……huge milestone. I am thinking about the step where you clamp and drill to 3/8” the rear spar for the AN-6 bolt. There is no steps to check incidence or level, etc. I checked my wings and the incidence is negligible and the wing tips are maybe .25“ difference with the main spar being level.
Is it as simple as this or do I need to take more measurements? I only want to do this once the right way. I understand on the other RV models there is a lot more fiddling around before drilling. Is the 10 different?

thanks

Keith

 

[Richard Connell]

Mine had 1/8 pilot holes already drilled in the rear spar and the carry thru forks.
They lined up perfectly first time.
So I just clamped and drilled. Like you the sweep and incidence were also negligible.

Do you have pilot holes?

 

[PilotjohnS]

Go on line and download the Vans document on drilling the rear spar.

Also, here on VAF, there is drill guide set floating around you can borrow to drill the holes absolutely perpindicular. I used it to drill mine and passed it on. It is a set of machined bushings(drill guides) that step up in sizes and keeps the drill aligned.

A quarter of an inch seems to be a lot. This means the aileron needs to be up (or down) that much to get the plane flying straight. I was off 1/16” and have a trim bias.

 

[rocketman1988]

There was no adjustment; just the pilot holes which lined up perfectly.

 

[Weefle]

Mine had 1/8 pilot holes already drilled in the rear spar and the carry thru forks.
They lined up perfectly first time.
So I just clamped and drilled. Like you the sweep and incidence were also negligible.

Do you have pilot holes?

There are indentations of where to drill the hole so one gets the required edge distance.

 

[Kyle Boatright]

There are indentations of where to drill the hole so one gets the required edge distance.

The -10 has predrilled holes. You cleco the spar in place, clamp the assembly, remove the cleco and drill. The existing holes serve as pilot holes so it is hard to make a non-perpendicular hole.

 

[Weefle]

The -10 has predrilled holes. You cleco the spar in place, clamp the assembly, remove the cleco and drill. The existing holes serve as pilot holes so it is hard to make a non-perpendicular hole.

I was overthinking this… drilled as per plans and reamed to 3/8”.

 

[YankeeBravo]

I was underthinking this very important hole and ended up with it 5 degrees offset from perpendicular. (I was able to perfectly correct following Van's advise to enlarge to AN7). I strongly suggest to use a proper drill guide to make sure you are perpendicular in all axis as the surface is small and the line surounding misleading.