07-30-2011: 7 hrs
Just came back from Oshkosh yesterday. Motivated to get the airplane done quickly. Spend some good time to finish all nutplates on the wing spar, and have the tie down assembly for the left wing done. I made some minor mistakes today, maybe I should slow down a little. But these mistake s are not structurally critical and no one will notice them. See pictures below.
Nutplates I need put on the left wing spar
One rivet on the nutplate was set perfectly, the real thing looked better than shown in the picture. This doesn't bother me since the rivet is really just to hold the nutplate in place, will not take big load anyway
all nutplate installed on the left and right wing spars, except the two (each spar) on the web
I made a punch mark on the spar again on the left spar, so I have sanded it off and primed it
I used the scrap material from rudder stiffener to make #6 and #8 screw hold dimple, I will use this to guide my countersinking
Screw holes are machine countersunk and primed
The two nuplates on the spar web are ready to be riveted
Nutplates are installed on the web of left wing spar
Shop head of nutplate rivet
Nutplates on the web of right spar
Ready for tie down assembly
I don't have 1" drill bit or fly saw, I used step drill bit to cut a 3/4" hole
Step drill bit is used to cut the lighting hole
I struggled the alignment of the spacer a bit, the clamping method per instruction didn't work well for me, so I used the double side tape to stick the spacer and tie down bar together
Holes on spacer and tie down bar are back drilled
Tie down assembly for left wing is done
Tie down assembly for left wing, this is not a good job as I would like, but it is structurally acceptable since the space is essentially a washer, and the rivets for nutplates don't take any big load. The load from tie-down or from aileron bellcrank brackets will be transfered to the tie down bar, not to the spacer
Tie down assembly installed on the left wing spar. The bellcrank brackets will be installed later because they will make bucking the skin rivet more difficult. I will install them before closing the bottom skin
