Canopy Decks (F-721) alignment after fuselage has been riveted

[RV7Factory]

The canopy decks (F-721s) were drilled to the longerons long ago, but now that the fuselage is riveted, they are a bit tight going back on. If I start clecoing them to the longerons at either end, I have to apply pressure laterally to get the holes to line up. With the first few holes in one end alinged the displacement of the holes worsens as you go along with the last hole off by about 1/4-3/8".

By applying pressure I can cleco them both on, and they lay nice and flat, but I don't like forcing anything into position.

I am inclined to just keep moving along, but I am curious if anyone out there in RV-land has encountered the same thing and what if anything you did about it.

 

[EricB]

Same here

Brad,

I had a similar result. While bending the longerons everything was spot on. As I recall, the displacement I had after rolling the canoe was about what you are seeing. The pressure I had to apply was minimal and I believe I simply put a cleco in each hole to pull it together then removed and added 1 rivet at a time. Everything else fit nicely after that, roll bar, panel, etc..

Eric
RV-7 FWF/wiring
Boise ID

 

[rzbill]

A couple of things

The F-721s were prepunched if memory serves. I imagine you had the longerons jigged into position like the plans said when you match drilled, so you have both sets of holes in the engineered positions. The longeron curvature has changed a little bit since then. Take a look at how you have the fuselage supported. It may still be flexible enough to be pulling those straighter than desired. I had to tug on mine a bit too. I don't remember the offset but they came together OK when I cleco'ed them all.

OK, now that that is past, here's a tip on couple of things to do BEFORE putting the 721's on.

Dwg 25 F-721A. Get them ready so you can solid rivet the two rivets that connect them to 721B. Squeeze these before installing on longeron. It is a PITA, nearly impossible, to do it after they are on the longerons. Many use pops here.

Dwg 25 Make up a dozen static clips and get a few of them riveted to the longeron under 721B beforehand.

Dwg 20 F-705G angle. Make sure you have all the match drilling done in that part and go ahead and put the 1/4" hole in for the static tube. It's nasty to do later 'cuz the drill motor won't fit.

Hope this helps. I fought all of those (you can tell, eh?) because of either forgetting or blowing them off 'till later. I simply made extra work for myself and nobody likes that.

 

[RV7Factory]

Thanks guys... I am just going to forge on. The fuse is riveted so there is really nothing I can do now but live with it.

Thanks for all the tips Bill.