| 4TH QTR 2002 |
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20/20 Hindsight Canopy Fitting Considerations: The fuselage of N360KJ was the fuselage that determined
all Kimball fuselages to follow. JKE made their fuselage construction jig from it and also the canopy jigs, one of which we
borrow from Kevin to place the bushings on our own hand built fuselages so we can use their excellent canopy design.
Like most welded structures made by hand, the fuselage of N360KJ varied from plans very slightly when it was finished.
Anyone that takes time to make accurate measurements of a Kimball kit fuselage will see the very slight differences that exist.
The Kimball canopy jig works great on Kimball fuselages because its all consistent. However, any non-Kimball fuselage
is going to be slightly different by a tiny amount, maybe just enough to make fitting the canopy a little frustrating, maybe not.
For me, my fuselage at the front of the jig is a little narrow, and at the rear of the jig is a little wide. To get the best
fit and operation of the canopy, I ended up racking the right side of the jig slightly forward, and eventually ended up
bending the forward hoop of the canopy itself to make it 1/4" more narrow at the front so the pins would engage good.
Your experience will vary, but if you take your time you WILL get a good fitting and smooth operating canopy.
I think the key is to make sure the jig is set on your fuselage so it puts the canopy hoop stub tubes equidistant from the fuselage centerline mark on the crossmember at station 0.0 firewall. |
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| 10/22/02 - 2.5 Assembled Kimball Canopy Jig, and loaded it with supplied bushings. I then clamped it to my fuselage and tack welded the bushings. I had to use some aft clamp pressure to get the jig aft against the FS 86.0 tubes because my fuselage is a little narrow up around FS 53.
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| 10/27/02 - 2.2 Discovered that canopy doesn't fit correctly into the 6 bushings, the pins on the left side don't engage fully into the bushings. Also discovered that the bushings had "sucked down" a little on the left side, probably from too much downward clamping pressure on the jig. Took pictures and emailed Kevin. His reply was to try again without clamps which might rack the jig. I cut the bushings off with a dremel, then tack welded them on again with the jig in a more relaxed position. Before doing so, I loosened the jig bolts, wiggled it around the re-tightened them. I then made trammel marks on the jig to ensure jig was not getting racked when put on the fuselage.
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| 10/28/02 - 2.7 Canopy is still not engaging pins on left side fully. Also discovered that windshield stub tubes are not equal distance from center of FS 0.0 crossmember, but the jig is not racked. The jig fits tight between the longerons at the front, but a little loose at the rear. Evidently it's yawing to the right a little when I push it down on the fuselage. I then measured with the canopy in place and figured out then I needed to get .19 or so relative movement between the left and right bushings to engage all pins on the canopy equally. I then cut the bushings off again, loaded the jig, and then forced the right side of the jig forward a bit then tack welded again. I actually had to rack the jig just a little, with the right side pushed a little forward. The bushings are even now. The distance from the two windshield stubs to center crossmember is equal too. The turtle deck looks like it will fit ok, with a nice even gap all between it and the aft edge of the canopy. Don't want to scrape paint later!
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| 11/08/02 - 1.2 Took canopy off and reinstalled jig. Tack welded canopy latch stop blocks in place. Note that they should flush with the INSIDE face of the jig plate. Test fit canopy. Removed canopy then reinstalled jig and bolted the hinge block holders to the jig.
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| 11/10/02 - 3.5 Removed metal from all 4 hinge blocks to fit against the longeron when in the jig, then bolted them in the jig. Note that there are two sizes of holes in each block, 1/4" and 5/16". The smaller 1/4" holes go to the inside and the bigger holes out. This allows for a long bolt to go through two hinge blocks without requiring perfect alignment. Tack welded them in. Welded up the rest of the bushings by doing short beads on alternating bushings so as to warp the longeron and knock the bushings out of alignment. Installed the windshield stub tubes and welded them in. Relocated the forward stop block just a pinch forward as it wasn't as far forward in the jig as it could be.
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| 11/20/02 - 1.3 Welded up the canopy latch stops. Reminder: Don't weld on the FRONT face of them or the canopy won't latch correctly!!! Also, welded up the canopy hinge blocks.
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| 12/07/02 - --- Moved the big 16' x 40" table out to the hangar so Phil could use it. Built an 8' x 30" table to work with now that I don't have the big one at home.
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| 12/13/02 - 0.9 Heated and adjust the angle of the left windshield stub post so the windshield hoop stays parallel with the front edge of the canopy. Welded the caps onto the windshield stub posts.
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| Quarter Total 14.3 hrs / TTD 532.5 hrs | |
| 4TH QTR 2002 |
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