6.10.2 Canard Top Attachment Points

The first step in the process is to remove the canard and place it on some saw horses. I previously trimmed the cover for a good fit and marked its location on the canard surface to make sure it is properly aligned. Because these pads, or tabs, need to stick out, I have to make something to do that. The manual recommends using some small boards or Dyvinicel scraps. You can see those in the photo below. I hot glued the Dyvinicel scraps to the side of the dog house cover to hold them in place while doing the layups.

IMG 2142

Creating installation tabs for the dog house cover.

IMG 2143

View showing the lay up inside of the dog house cover.

The layups have cured and have been trimmed so I reinstalled the canard back in the fuselage to check for fit. Luckily it all fit perfectly!

IMG 2144

The canard with the finished tabs is back in the fuselage. These tabs not only hold the cover on but will also be used to prevent torsional movement once they are locked to the fuselage.

IMG 2145

Another view showing the completed canard tabs.

Once the tabs on the canard are cured, it’s time to make mating pads that eventually get attached to the fuselage walls. Because these pads stick out, the manual again recommended that I use boards, or whatever, as a backing for the Triax that’s used for this. In this case, I decided to use some cardboard covered in duct tape (which acts as a release agent) for making these pads.

IMG 2146

I'm using some cardboard covered in duct tape to create forms for the tabs that get attached to the fuselage.

After the layups cure, it’s time to separate the duct tape covered cardboard from the pads. I also need to remove the canard again so that I can trim and match the shape of the pads between the two surfaces. The photo below shows one of the pads as I prep it for attaching a 1/4” nut plate.

IMG 2147

Here's a closeup shot of one of the finished fuselage tabs.

IMG 2148

I needed to create four tabs altogether - two in the front and two in the back. This photo shows both tabs on the left side of the aircraft.

If you look close at the left side of the photo below you can see the 1/4” nut plate that’s installed on the fuselage pad. The locking bolt passes through the tab on the canard to the pad on the fuselage and locks the assembly together. All four corners are attached the same way.

IMG 2149

This view shows the completed left side tab with bolts in place locking the carnard to the fuselage.

Because I purchased the side stick controller option, I needed to create some openings in the tabs for the elevator torque tubes to pass through. You can see that in the photo below.

IMG 2150

After completing the tabs I had to cut access holes in them so that the elevator torque tube control can get through.

IMG 2151

Here's a wider view of the completed tabs showing the side stick controller in place.

The manual recommends drilling holes through the cover and into the tabs for holding the cover down to the canard. Most builders no longer do that. They try to keep the surface of the airplane as smooth as possible. Some people use hinges to attach the cover to the canard, but that seemed like somewhat of a pain. So, I purchased some Dzuz latches and will use those to latch the cover to the canard. The neat thing about these latches is that they can be safety wired shut eliminating the concern that the latch may pop open letting the cover go flying. When the cover needs to be removed it’s easy enough to cut the wire, pop the latch and open it up! (See followup to this below. It turns out that trying to get these latches aligned is more difficult than I thought it would be, so I’m switching over to the piano hinge concept.)

IMG 2154

I'm using some Dzuz clasps to hold the dog house cover to the canard. What you see in this photo are the mating hooks for the clasps.

Since many builders end up installing their panel electronics underneath the dog house cover, (which I also plan to do) I am a bit concerned about moisture getting in through the gaps between the cover and the fuselage. I decided to try to seal that area by making some flanges which will get covered with a rubber seal. To make those flanges, I decided (after a number of other attempts at doing this that didn’t work well at all) to use the cover as a mold. I also need a slight edge for the rubber seal so I used some 1/16” cardboard to create that edge along with more cardboard outside of the dog house cover to create a surface that I could use to epoxy it to the underside of the fuselage. This actually worked quite well, even though it was an involved process, as you can see in the photos below!

IMG 2155

Prepping the dog house cover to make short ledges to be used for water proofing the cover to canard intersection.

IMG 2156

Here's a photo of the completed layups using the dog house cover as a form.

IMG 2157

Here are the two water proofing flanges after removing them from the dog house cover and before installing them onto the fuselage.

I think I used just about every clamp I had to hold those flange pieces tightly against the fuselage while the epoxy cured. In the end, it worked well. And since I was using EZ-poxy + Microballoons for the mixture, I was also able to smooth the transition between the fuselage and the flanges in preparation for applying a layer of BID later to protect the edges.

IMG 2158

It takes a lot of clamps to make sure that the ledges adhere properly to the fuselage.

I’m finally getting around to protecting the edges of the dog house cover with a layer of BID. Eventually a light coating of Velocipoxy + Micro will seal the edges before getting painted.

IMG 2194

I need to protect the edges of the cover so here's a photo showing one layer of BID epoxied in place before trimming.

The photo above still shows the Dzus clasps that I had planned to use to hold the cover down. Well, basically, I wasn’t happy with the way in which they are working. It became too hard to get them aligned properly, especially with addition of the ledge seal. So, I’m switching to piano hinges which other builders have used successfully. Stay tuned for more about that below.

So, the clasps came out and the hinges are going in. I probably should have just done it this way to begin with but I thought I had a better idea. Shows you what I know! Ha ha! I just couldn’t get the clasps to align properly so I tore them out, bought some hinges from Aircraft Spruce and went to work. Installing them is pretty easy and it’s much easier to get everything aligned.

The Clecoes, shown below, are temporarily holding the hinge in place. They come out when I epoxy and rivet the hinges in permanently.

IMG 2211

One of the hinges used to hold the dog house cover in place is temporarily Clecoed into place before applying epoxy and rivets.

Since the hinges curve ever so slightly, I was having problems getting the hinge pins to re-insert. I used my belt sander to grind the ends down to a slight point and that did the trick. Adding a bit of grease on the pins makes them slide in fairly easily. 

IMG 2213

In order to help the hinge pin go through the slightly curved hinges, I tapered the end of the pin slightly on my belt sander.

There’s still a bit more work to do so stay tuned for a few more photos.

ui© John Trautschold 2018