Chapter 12 - Section 2

Aligning the Canard

 

  Fitting Alignment Pins    Aligning the Canard   Fitting Elevators & Torque Tube to Fuselage 

 

Aligning the Canard

First, I made sure my fuselage was level fore and aft as well as side to side. Since my main gear is still attached to the fuselage, all I need to do is to find a way to raise the front of the fuselage until it is level with the rear. I clamped a couple of 2x4's along both sides of the fuselage and 1 across & under the fuselage. With the help of a digital level, I got the fuselage leveled as needed.

 

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. 

 

 

 

 

 

 

 

 

Setting the Canard Perpendicularity

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 

After searching through the archives, G template is the template of choice for setting the canard incidence - no problem there. However, the original G template from drawing M-18 is not the correct one. A 'modified' G template was released with Newsletter #80. Well, I did not have Newsletter #80 and the modified G template was not available at the 'Unofficial Cozy Site'. I called Aircraft Spruce and the person who knew anything about the Cozy Newsletter (Renee) was on maternity leave. I asked for alternate support and was disappointed to get one of those "I have no idea, just have to wait till she gets back" type answer. I posted a request to the Forum and received an original copy as well as a scan-in version of the template two days later (within hours apart).

 

 

 

 

 

 

 

 

 

 

Checking the Canard Incidence

I laid the modified G template over the original template to determine the difference. The height of the forward edge was decreased by .3", everything else remains the same. In other words, put a mark 0.3" below the top left corner of the original template and draw a straight line joining this 'new' mark to the top right corner of the template. This equated to a 1.15 degree increase to the canard incidence. I made a 1/2" thick wooden G template with the new dimensions and added stir sticks (shims) to the front edge of the canard until the digital level on the top of the G template registered 0.0 degree. As shown, the canard is leveled side to side,  and 0.0 degree 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

I made the alignment tabs out of .25" birch wood - just because I feel it has more substance to it (though the plan suggests Clark foam is OK as well). I drilled the alignment holes and trimmed them to length.

 

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.

 

Lift Tabs

I followed the plan's procedure and drilled out the lift tab bolt holes. It worked well.