I was not satisfied with my first canard build. I overfilled the spar cap with plans to sand it down to meet the contour, however I had to sand much more on the top spar than I planned and I started to question if I had sanded too much, broken too many fibers mid-span, etc. I think it's probably just fine, but rather than always have that question in my mind, I decided to rebuild this most critical part of the airplane...but now with improved skills.
The next few posts are the original canard build posts but edited where needed to reflect the 2nd canard build. Many of the pics and description are still the same...I just did it better.
To Hot Wire or Not to Hot Wire...
I decided not to hot wire my own cores for the canard...and likely won't for the wings either. Since Eureka CNC does such a great job at a reasonable price, I figured why mess with trying to get the cores correct and the templates shaped perfectly for such important pieces. I would have ordered the entire canard/wing package deal but I didn't have anywhere to store the wing cores until I was able to start building them.
|Assembled canard cores minus the leading edge,|
outboard cores, and tips aligned in the 2x4 jig.
The cores were perfectly cut and assembled easily. I built the 2x4 canard jig per the plans. The FAQs on the Cozy page discuss using 12" 2x4s for this, and you certainly can, but 10" works just fine. You'll have approx 1' hanging off of each end but it's not enough to create any problems.
If you're wondering about the thin ply underneath the jig...I glued the 2x4s to this thin ply rather than the table top so that I could move it if needed.
|Fishing line used for alignment of cores|
|Fishing line running just above, but not touching|
the top of the cores helped with alighnment
I followed the plans to dig out the foam and install the lift tab nut plates with no issues. I purchased the canard lift tabs and nut plates from the Cozy Girrls. They are very nice, already abraded and ready to install hardware. If I haven't said it, I highly recommend the hardware available from the CG Products.
Be sure to clearly mark the nut plate jig as to the direction it goes and whether it's left/right or port/starboard or whatever. You'll re-use these to drill the bolt holes through the glass once the shear web hard points cure.
|Well marked Jig|
After installing the nut plates, glassing of the shear web went per plans with few issues. I recommend using good masking tape to tape off the portions of the cores below the spar trough. I used a mediocre duct tape which didn't stick very well and allowed epoxy to leak below the tapeline causing me some clean up work later to ensure the airfoil contour was not disturbed. Gorilla duct tape and the like is too sticky I think...might pull foam out when you remove it.
|Port lift tab installed|
(w/peel ply around it)
|Starboard lift tab installed|
(w/peel ply around it)
Next, the leading edge was reinstalled per plans, and the canard was set in the template K jig blocks and aligned nice and straight. PS...I also purchased the canard jigs from Eureka CNC and highly recommend those as well. You just don't get better than 10 identical CNC machined jigs. I had spent time building a very flat bench where I used two 30" solid core doors as the bench top. The top was flat to within .1% of my digital level. I felt that as long as the top was flat, there should be no reason to have to shim anything. On the 2nd canard, I ended up shimming the end of the port side slightly. I think the rear of the port canard core got slightly twisted up during alignment. Time for the bottom spar cap.