Model A QB Kit: Drilling wings and struts

[Dpearson]

Hi all - Sometime this summer I'm planning on match-drilling my A-model QB wings to the fuselage, and trimming/drilling the lift struts.
I've scoured this forum and the other Bearhawk sites, and have found what I think are the most recent instructions for my (quite old) kit:

Drilling wings to Fuselage: https://bearhawk.tips/3113
Making the struts: https://bearhawk.tips/3689

Are these the latest guidance? Any other sources of info (other than the plans) I should be looking at for these steps?

I've got the fuselage on the gear, and will of course chock the mains well and probably run a ratchet strap between the main wheels to prevent any "splay" from occurring. And I'll build a tail stand as mentioned in the instructions.

For wing stands, I plan on using 4 Harbor Freight tripod stands (idea from https://www.kitplanes.com/support-your-wings/ ) - a photo of what I built is below.

I will be working in my driveway, as the garage isn't big enough for the job. I figure the work will take at least 2 days, so I'll get to camp under a wing well before first flight!

Feedback and advice from the many of you who have "been there and done this" would be welcome.

 

[rodsmith]

Make yourself a water level. You will want a drilling jig, maybe someone on the forum will loan you one, or you can build one. I started with 3/16" holes and worked up 1/16" at a time. Use a reamer for final size. You are going to need an extension for the drill bits/reamers. Sacrifice some hardware store bolts grinding the threaded end smaller to initially pin the wings. I think a digital level is mandatory for getting the wing incidence correct, and it needs to be shimmed correctly to insure it is measuring parallel to the chord line. Get plenty of help. In my case I thought 4 people was about right. Hope you don't have much wind for the two days!

 

[spinningwrench]

I’m drilling wings this week. Tail held with Harbor Freight jack and welded fork to pick up tail wheel stinger hole. Each wing held by roll around stands using 1/2” vertical pipe. The pipe has two clamp collars that allow me to tweak the wing height and dihedral. The pipe stands are cross braced with material from wing crates.

 

[Dpearson]

​​I hit a stumbling block last night when test fitting the upper strut ends to the steel straps that stick out the bottom skin of the wing. The strut ends contact the wing skin and prevent the holes from aligning properly - by eyeball there's ~ 1/16" interference. ​​

I notice that the strut ends that came with my (very old) kit don't quite match the plans - they are 2 parts (vs the single part shown in the plans), which seems OK, but they are missing the "neck down" feature that brings the width down from 1-1/2" to 1-1/4" (5/8" Radius) at the "wing attach" end. So that seems to be the source of the interference.



Has anyone seen this before? I feel like I'm missing something obvious... I'm inclined to take just a bit of material off the strut end to resolve the issue, but thought I'd ask those more knowledgeable than me first.

 

[Mark Goldberg]

Those are how Bob originally had us make those parts. The three pronged ones like we currently supply came later. You can just remove a little material and not compromise strength and will get the holes to align. Should not be an issue. Mark

 

[Dpearson]

Hi Mark, that's great news. Thanks for the quick reply!
David

 

[Dpearson]

Wing drilling and struts done! Thanks to all for the advice and guidance. Working in my driveway was somewhat congested but my next door neighbor was happy to let the right wing overhang her yard.

 

[alaskabearhawk]

Congratulations! You are officially the crazy guy in the neighborhood who is building an airplane in his yard.