F-771 fitting problems

[PIN 37]

After 7 years of building I went today to fit the F-771 forward top panel. I had left this panel off so as to make wiring the avionics up easier. The fuse has been sitting on its wheels for about 4 years and a motor has been hung for approximately 3 years. The thing is I started clecoing the panel on from the centre to the outside. When I got to the longerons I could not get the clecoes in because it appears the top panel is displaced rearward about 1/16 - 5/64 rearward. No matter how hard I tried to move the F-771 panel forward to align the holes, it would not move. A number of questions arise here, 1) has anybody else had this problem and if so how did you fix it? 2) does this mean I will now have to throw my canopy away because it has previously been fitted to cleco stage. 3) is this a result of not fitting the F-771 panel earlier? Any help would be appreciated.

[rzbill]

Obviously you will need to go back to the beginning and start from scratch. Sorry, just kidding.

I do remember that this skin was one of the few that was "tight" to assemble on my craft.

I'll suggest some techniques that may help you.

1) You can check one side at a time by clecoing into the longeron first and then trying to cleco the firewall and subpanel bulkhead. Its certainly not an install method but it may tell you something new.

2) Pre bend the panel. Carefully (so you don't kink it) roll it to instill the two curves into the panel. I did not get much of a curvature to "stick" but anything helped.

3) When cleco'ing from the center, don't put all the clecos into the curved sections. I know you can't get the longeron clocos in without some help from a couple of clecos in the curved section but keep them to a minimum such that you can still move the panel fwd and bwd at the longeron.

4) Focus on getting the AN4 holes lined up.

5) And lastly, I know on one occation (I remember one post in 7 years) a builder got new sheet and cut a new skin using the current prepunched part as a guide and left out the problem holes for drilling in place on the craft. Good luck in your endeavor to avoid this step.

An afterthought...Do you have shims on top of the subpanel bulkhead curves? These would move the longeron holes in the skin rearward.

[PIN 37]

Finally rivited on the top panel today. Big milestone. Only the final fitment of the canopy to go, then assembly. got the top panel fitted by using ratchet straps right around the fuse and started to cleco from the longerons to the centre. A liberal amout of swear words helped as well, still, all done now and very happy with the result.