Just started recently on my QB wings. I'm in the process of verifying what construction steps have been completed. So far, I found that not all of the snap bushings had been installed (no problem). Also, the bottom flanges of the wing ribs and rear spars had not been dimpled. No problem overall and working on the couple of places where it is a problem.
However, I've now found what I think is a much bigger issue: the rear spar attach holes were not reamed (page 15-04, step 7 [in revision 2]). That should have been done on a drill press before the rear spars were attached to any ribs. The holes should be reamed to 3/8" but they measure about .348". I can get the shank of an 11/32" bit into the holes but not a 23/64". The only solution that I can see is a drill guide of substantial thickness very securely clamped to the rear spar and very carefully positioned. I have a machinist/pilot friend who is glad to make these things for me. Besides the drill guide, I'd probably have him make a 3/8" pin with a tapered end to do the centering. Hopefully, I can get a drill guide made that would be thick enough to just get the reamer through the guide and rear spars.
I generally use a DeWalt cordless drill for most of my drilling but I'm wondering if it will have the necessary torque to drive a 3/8" reamer through the rear spar.
On top of those concerns are those about my building skills. I'm a first-time builder and I've paid PLENTY in the form of the "stupid" tax. For instance, I was just in the process of performing SB 16-03-28 on my wings. Got the rivets for the inboard aileron hinges removed without issue (those 16 rivet holes are better than any of the 24 practice rivet removals I did beforehand). But, in prepping the new hinge bracket parts, I over-countersunk two holes. It hurt to do it, mostly because of lost time, but I ordered a new SB kit to replace those two parts. However, if I make a mistake reaming these rear spar attach holes, I'd probably hang it up on this project! I can just imagine the drill torquing on me and moving the drill guide although I don't think I've ever had a reamer torque on me.
BTW, I checked the corresponding holes in the QB fuselage and they seem to be properly sized (3/8" bolt just barely fits).
I'd be glad to hear all your thoughts.
However, I've now found what I think is a much bigger issue: the rear spar attach holes were not reamed (page 15-04, step 7 [in revision 2]). That should have been done on a drill press before the rear spars were attached to any ribs. The holes should be reamed to 3/8" but they measure about .348". I can get the shank of an 11/32" bit into the holes but not a 23/64". The only solution that I can see is a drill guide of substantial thickness very securely clamped to the rear spar and very carefully positioned. I have a machinist/pilot friend who is glad to make these things for me. Besides the drill guide, I'd probably have him make a 3/8" pin with a tapered end to do the centering. Hopefully, I can get a drill guide made that would be thick enough to just get the reamer through the guide and rear spars.
I generally use a DeWalt cordless drill for most of my drilling but I'm wondering if it will have the necessary torque to drive a 3/8" reamer through the rear spar.
On top of those concerns are those about my building skills. I'm a first-time builder and I've paid PLENTY in the form of the "stupid" tax. For instance, I was just in the process of performing SB 16-03-28 on my wings. Got the rivets for the inboard aileron hinges removed without issue (those 16 rivet holes are better than any of the 24 practice rivet removals I did beforehand). But, in prepping the new hinge bracket parts, I over-countersunk two holes. It hurt to do it, mostly because of lost time, but I ordered a new SB kit to replace those two parts. However, if I make a mistake reaming these rear spar attach holes, I'd probably hang it up on this project! I can just imagine the drill torquing on me and moving the drill guide although I don't think I've ever had a reamer torque on me.
BTW, I checked the corresponding holes in the QB fuselage and they seem to be properly sized (3/8" bolt just barely fits).
I'd be glad to hear all your thoughts.