Fitting Alignment Pins Aligning the Canard Fitting Elevators & Torque Tube to Fuselage
Aligning the Canard |
Note the saw horse under the fuselage is my fail safe support, in case the C-clamps decide to give out. So far, they have been holding up OK.
Once the fuselage was leveled, I placed the 12' canard over F-22, it was 0.1 degree off - with the starboard side low. That was easy... a 1/16" washer took care of the problem. |
The plan suggests to put the top half of the firewall in place (temporarily) to set the canard perpendicularity. Instead, I clamped a straight edge at the center of the lower firewall, with its edge right along the plumb line (where I used it to set the center line of the fuselage fore and aft earlier). I also extended the tip of the straight edge above the top of the longerons (W.L. 23) so that I can have a line-of-sight to the wing tip corner of the canard.
I
first used a measuring tape but it sags. Then I tried a long stick but its not
perfectly straight. Then I tried a 22 gauge wire and a strong fishing line but
they both stretched ... I
finally tried a long picture hanging cable that will not stretch under tension.
I was able to set the perpendicularity of the canard. My initial measurements were
119.5"
starboard and 119.25" port side. I added a .062" thick washer as a
shim behind the port alignment tab and the canard perpendicularity fell in
place. My final distance from the centerline (at some height above longerons) is
119.4" on both sides.
The Elusive G Template |
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Checking the Canard Incidence |
I made up an 8 layer BID tape and glassed it onto F-22 to replace the washer. After cure, I re-mounted the canard and re-measured the perpendicularity of the canard. After minor sanding, I got my 119.4" back on both sides. I also drilled the pilot holes through the lift tabs, making sure the canard is still level at 0.0 degrees. |
Alignment Tabs |
Using the 5 minute epoxy to hold the alignment tab in place (per plan) is OK, but I was not comfortable in leaving it in place as the fillet material for the subsequent 5 plies of BID. Besides, I know I can make a better fillet with flox than 5 minute epoxy. Therefore, I hot glued the alignment tabs in place first and then applied dry flox at the joint. Right before laying up the BID, I smoothed out the dry flox with pure epoxy using a soft brush. Then I carefully removed the alignment pin and laid out the BID and peel ply. It turned out nice. Once cured, I dismounted the canard and glassed the bottom side of the alignment tab with 4 plies of BID per plan.
After cure, I opened up the alignment tab holes again to 3/16" for the AN-3 bolts. With the bolts in place and canard incident at 0.0 degrees, I floxed and glassed the 4" alignment pin tube in place. After cure, I opened up the alignment pin holes (on the tab) to 1/4" to accommodate the CN-2 bushings. Then I 5-min epoxied the CN-2 bushings in place. |
I followed the plan's procedure and drilled out the lift tab bolt holes. It worked well.