Tipper Canopy Shift

[Av8torTom]

I recently Sikaflexed my tip-up canopy into the frame which turned out quite nice. However, after connecting the gas shocks the rear canopy bow has moved forward almost 1/4" to the point where the canopy attach lugs will not go into the square hole to engage the latch. I could easily shim out the latch lugs, but I wanted others' insights on this before I did anything.

Thanks,

Tom

[rv7charlie]

What do the sides look like, relative to the fuselage top longerons? Are the struts making the sides bow out?

Wait; do you have the top skin riveted on, and the firewall riveted? (Hard to tell from the photo sequences.) If not, the struts might be pushing everything forward.

Charlie

[Av8torTom]

I do not yet have the forward skin riveted on to the firewall (or any place else), but nothing looks out of line forward of the canopy. The sides of the canopy frame fit the longerons perfectly

[gasman]

Now is a good time to install a piece of angle on the longeron behind (engine side) the sub panel with a nut plate on it. Drill through the sub panel to install a bolt that can later be adjusted to stop the canopy where you want it to fit.

The strut is always pushing..... this gives it something to push against when the canopy is closed, and reduces stress on the canopy frame. It also eliminates forward canopy skin crunch.

[rv7charlie]

Originally Posted by Av8torTom

I do not yet have the forward skin riveted on to the firewall (or any place else), but nothing looks out of line forward of the canopy. The sides of the canopy frame fit the longerons perfectly

Try cleco'ing the forward skin on while the canopy & struts are installed and the canopy is closed. & see if all the top skin/structure/side skin holes line up.

[rvbuilder2002]

Canopy position will a lot if the fwd skin is not riveted on.

[sahrens]

I suggest clecoing the forward skin in place, climb in and lower the canopy. Watch the forward part of the strut. You will be surprised how far the strut, and canopy, moves forward; even with the forward skin on. I certainly was surprised.

The solution that many have used is to reinforce the structure in front of the canopy at the longerons. This prevents the canopy struts from extending forward in the lowered position. I would direct you my build log but Bruce Hill's is better and I copied his method anyway. Go to www.overthehills.com and look at his canopy log.

http://www.overthehills.com/RV-9A-Pr...nopy/i-CwkzjVz

Another web log is Bruce Swayze's. He used a different technique to get to the same end.

http://www.europa.com/~swayze/RV-7A/.../20120225.html

I am sure there are hundreds of other techniques here on VAF, pick the one you like. Good luck on your build.

I hope Bruce Hill and Bruce Swayze don't mind me referencing their web logs. If either do I will delete my response.

[bruceh]

I don't mind! That's why it's there.

I did have to open up the squarish holes for the latch lugs at the rear of the tip up canopy. The plans don't give you a lot of room there with the initial size. The best thing to do also is put some guide blocks to assist in lining the lugs up with the holes.

[LettersFromFlyoverCountry]

Yes, way better than the method I used, although both accomplish the same goal.

[Rupester]

Originally Posted by gasman

Now is a good time to install a piece of angle on the longeron behind (engine side) the sub panel with a nut plate on it. Drill through the sub panel to install a bolt that can later be adjusted to stop the canopy where you want it to fit.

The strut is always pushing..... this gives it something to push against when the canopy is closed, and reduces stress on the canopy frame. It also eliminates forward canopy skin crunch.

Exactly .... Just like Gasman said.