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Cozy Mark IV : Time and Expenses

Chapter 12: Canard Installation

In this chapter you will fit the canard to the fuselage, aligning it so that it is level, perpendicular to the longitudinal axis of the fuselage in plan view, and with the airfoil at the correct angle of incidence.


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Chapter 12

# Desc Date Cost Time (hours) Details
1. Brock parts 7/29/05 16.84   CNL, CN2.
2. Chapter kit   2.05   Order from Spruce.
3. Alignment pins 8/27/06   8 Cut the head of two AN3-20 bolts with a hacksaw (my poor arms!) and filed down to a point.  Drilled a #10 hole in each doubler, perpendicular to the longitudinal axis.  Inserted the pins and checked alignment.   Positioned the canard on the fuselage, aligned the center, and clamped it in place by the lift tabs (after protecting them with masking tape).  It was perfectly level, but it was not square and the incidence was not right.  I had to use two 1/16" shims to get the canard square, which translates to 9 plies of BID added to the left side of F22.  Shaped the side of the fuselage between F22 and F28 to get the incidence right.  Rechecked level, square and incidence.  It's as close as I can get it in any one dimension without messing up another. 

Cut the top tabs from .25" birch and drilled #10 holes to match the pins I made above.  Repositioned the canard with aluminum shims .016".  There were no holes pre-drilled in the attach tabs underneath the canard, so I carefully measured the position of the holes and drilled through the tabs and F22.  Attached with some AN3 bolts and rechecked.  Fixed the birch tabs in place with 5ME, and covered with five plies of BID.

4. Fitting elevators & torque tube to fuselage 8/28/06   6 Sanded the BID from last night to the shape of the alignment tabs.  Drilled the #10 holes through.  Sanded a radius edge on the bottom of the alignment tabs and laid up 4 plies BID on the aft side.  After it cured, I drilled the #10 hole through (again!), and opened it up to 1/4".  Add the CN-2 bushings with 5ME.  I then had to sand and re-file the alignment pins again a bit to get them to fit through the bushings smootlhly.  I put the pins back in place, put the canard back in place, and then opened the holes in the attach tabs to 1/4".

Removed the canard and attached the elevators.  D'oh, of course, the canard will not fit on the plane until the elevators have been trimmed to match the contour of the fuselage side.  This is a catch-22: I can't put the canard on with the elevators, but I don't know how to trim the sides of the elevators without putting it in place!  I removed the canard, removed the elevators, and then put the canard back on the plane without the elevators.  I used a piece of 1/4" wood scrap to make a make-shift template against the side of the plane, carefully marking the position of the template on the top of the canard.  I then removed the canard and re-attached the elevator to it, and put the template back on top of the canard.  Sure enough, the alignment from the template showed me exactly where to make the cut on the elevator.  I marked the line, cut the elevators with a hacksaw, sanded it down, and then re-fit it on the plane.  Perfect!  I was then able to sand down a depression in the fuselage sides for the torque tube offsets.  When everything was re-positioned correctly I removed the canard, and put 1 ply BID over the top of the fuselage sides.

5. Floxing alignment pins 8/29/06   1 Sanded and trimmed the BID around the top of the fuselage sides and in front of the doublers.  Opened up the 3/16" holes in the doublers to 1/4".  Re-fitted the canard and checked the level, alignment and square ONE MORE TIME before floxing pins in place.  Everything checked out so I removed the canard, covered the front of the doublers and the back of the alignment tabs with box tape, filled the holes with flox, re-positioned the canard and carefully inserted the alignment pins.  (This is slightly different than the order described in the plans.  With the holes too big for the pins, I felt that inserting the pins first would allow them to wiggle a little too much for my comfort as I slid the canard in place.  So I did the canard first and used the box tape to protect the parts from any escaping flox when I inserted the pins.)  Left the lot to dry.

Chapter total: Time 15 hours, Cost $18.89

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Last modified: Monday, May 07, 2007