Chapter 12: Canard Installation


Lessons Learned

1. There wasn't enough room between F22 and F28 for my canard to fit, so I moved F28 back to 6.25 inches behind F22. This is a known problem and it is detailed in Zeiltlin FAQ 12.1 and 12.2.

2. Setting the canard up properly was a ritual in itself. There were always four things to check -- (a) level fuselage fore/aft/side-to-side, (b) set incidence with shims, (c) check perpendicular measurement from firewall, and (d) check canard level. Adjusting one meant rechecking them all again.

3. The biggest headache was getting the canard incidence angle set to 0 degrees. Because the G template that I used is only 1/4-inch thick, I had a tough time balancing it and the smart level. I kept getting inconsistent measurements of the incidence along the length of the canard. I got fooled into believing my canard was twisted somehow. So I decided I'd better fill and sand the canard to profile first before installing onto the fuselage. So, I made a sanding block from 5 poplar boards carefully cut, stacked, and hand-sanded to exact profile. Guess what? Using the sanding block, I found out my canard was bone straight with no twist whatsoever. So I went ahead and permanently mounted the canard. I'll postpone the fill and sanding…

4. I used a water level to level the canard to the fuselage. If you've never used a water level before….due to Mother Nature, water in a tube will seek it's own level. So the water mark at one end of the tube is exactly level with the water mark at the other end of the tube. With one tube end on the port trailing edge and the other at the starboard trailing edge, you can adjust the canard perfectly level.

5. I used about 9 layers for the starboard BID pad to get the canard perpendicular with the fuselage centerline. I also did a fair amount of trimming along the top of F22 bulkhead to level out the canard. Your mileage will vary.

6. I used birch for the alignment tabs. I didn't like the idea of using clark foam.

7. I haven't permanently installed the alignment pins. I'm thinking about attaching the alignment tabs with bolts and nutplates as stated in Zeitlin FAQ 12.6.

8. I trimmed the Brock bushings to fit before floxing them in place. Certainly made it a lot easier to file down flush after cure. Otherwise, be careful if you try to trim them in place on F22. If they get hot enough, the flox will melt and the bushings will fall out!

9. I found that my lift tabs were off a little bit, i.e.- they were not parallel to the forward face of F22. So, I wrapped the tabs in box sealant tape and applied a liberal amount of flox on the backside of the tabs. The cured flox takes up the gaps between the tabs, bushings, and forward face of F22 and creates a nice bearing surface. (I guess a lot of builders have seen this… it's explained in Zeitlin FAQ 12.5.)

10. I was a bit sloppy when fitting the canard, so my fuselage sides were not perfect fits to the canard. So instead of applying 1 BID as called for in the plans, I taped up the MK12A offset spools and canard and simply stuffed flox into the gaps. Worked great!


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