Fitting Cabin Top

bnovak1220 · #1 02-10-2018, 05:38 PM

Checking to see if anyone else or if everyone has the same thing going on. I am running out of fiberglass on the sides of cabin top trying to get it down on the plane. I see that I need to counter sink them later and not sure if there will be enough fiberglass left.

https://www.flickr.com/photos/156228993@N06

Electrogunner · #2 02-10-2018, 06:12 PM

It does get fairly thin, probably 3/16?-1/4?or so. There will be plenty of material left to hold a countersink. Take off a little at a time until it slides in. I had it on and off probably 10 times for the fit. Patients, don?t rush it.

Kyle Boatright · #3 02-10-2018, 06:16 PM

I had the same concern in the door area (that's what you're talking about, right?) but there was plenty of material left at the end.

The countersinks turned out fine.

bnovak1220 · #4 02-10-2018, 06:30 PM

Ok I attached a link to a photo of the area I'm talking about. Not sure if it will work. anyway I'm down to 1/8" outer lip and still doesn't fit.

https://www.flickr.com/photos/156228993@N06

Kyle Boatright · #5 02-10-2018, 06:53 PM

Quote:

Originally Posted by bnovak1220

Ok I attached a link to a photo of the area I'm talking about. Not sure if it will work. anyway I'm down to 1/8" outer lip and still doesn't fit.

https://www.flickr.com/photos/156228993@N06

Mine was that or less. It was razor thin at the very edge. Thicker farther inboard.

Kinda spooky, huh? ;-)

Bill Boyd · #6 02-10-2018, 07:38 PM

Mine got pretty thin, too. Not an issue. When you look at it in final position, you realize the screws (in tension) along the bottom of the doorway have nothing to do with holding the top on, They only keep the "door jamb/threshold" steady when the door seats against it. I believe flox would hold it just as well.

The screws in the doorway sides and the rivets below the rear windows (in shear) are 90% of what hold the top in place against air loads, etc.

Don't sweat it. Keep trimming and fitting till it squeezes into place.

bnovak1220 · #7 02-10-2018, 09:09 PM

Thanks guys that makes me feel better - going to hit again tomorrow and build on!

Electrogunner · #8 02-11-2018, 06:44 AM

Quote:

Originally Posted by Kyle Boatright

Mine was that or less. It was razor thin at the very edge. Thicker farther inboard.

Kinda spooky, huh? ;-)

razor edge. My hands can attest to that, it got me a couple times before it was permanently attached

Bill Boyd · #9 02-11-2018, 07:02 AM

Berkley, if you want to see one under construction with canopy mounted, go visit Jack Philips at Bedford Landings, Smith Mtn Lake. I assume it's not far by road from LYH. There may be others in your area also. Jack and I are about the same stage on the airframe, and he just got his panel in and powered up.

rocketman1988 · #10 02-11-2018, 07:56 AM

If you have the QB fuselage kit, there is a gotcha to watch for with the cabin top install.

Check to make sure that ALL of the rivets in the fuselage sill, both horizontal AND vertical sections ARE FLUSH RIVETS.

My QB fuse came with AN470 button head rivets in the vertical sections of the aft sill, 7 on each side. This made fitting the cabin top difficult and would have resulted in very thin fiberglass sections had I not found the problem.

Replacing those 14 rivets was fairly easy as access was available. When the flush rivets were installed the cabin top fit much better. There were still areas where the flange gets razor thin.

The plans say to just sand off the flange to the radius but I think most people will agree that they had to go well into the radius to get the top to fit. Seems to me that the cabin top door should have been 1/4" smaller. Then the plans would have been correct and most of us would still have a fiberglass radius on the edge...