Chapter 10 - Step 2

This step involves gluing all the cores together, adding the lift tabs, and applying the shear web layup.

Lift tabs and inserts June 23, 2001. Here are the lift tabs and inserts from Brock after I added the nut plates with some rivets. To get the nutplates just right I inserted a bolt through the hole in the insert into the nutplate (just a thread or two). I then drilled one of the rivet holes. After slipping a rivet in that hole I could then drill the other hole knowing everthing is lined up properly.

Jigging Cores June 23, 2001. I spent quite a bit of time prepping the cores making sure the ends where exactly the same and making sure everything would be straight. To make sure the centerlines were correct I temporarily attached the leading edges to the rest of the cores. I then measured the center of the aft face of the leading edge. This mark was made on the shear web face. I now had marks that would allow me to check the straightness of the three cores in the jig.

Alignment String June 23, 2001. To ensure the trailing edge was straight I put two nails in the table at each end of the canard and strung a string between them. I then made sure the top of the "fin" just touched the string.

Insert Jigs June 28, 2001. Here are the lift tab inserts jigged in place. First I cut the boards to the right height to hold the metal strip in the right place. I then drilled the holes in the metal strip to match the lift tabs. I then bolted the inserts on the underside of the metal strip. Since the screws are so long I also used the lift tab and several washers. I then marked where the nails would need to be and drilled holes in the strip for those. I then layed the strip in place and used those holes to drill holes in the wood blocks. Now that everything fit I filled the recess with dry micro and layed the metal strip in place with the inserts. I put the nails in place, cleaned up the excess micro and let it dry.

Masked Cores June 30, 2001. After removing the metal strips from the inserts I prepped the canard by lightly sanding the canard core joints so there were no bumps. I then applied masking tape down the length of the canard, both sides, so excess epoxy wouldn't drip anywhere. The tape nicely bridged the gap between the foam core and the 2x4 so there is no way to get glue anywhere but on the shear web surfaces.

Lift Tab Hard Point July 3, 2001. After putting the metal strips back in place to drill the lift tab holes in the shear web face I quickly realized I was going to have some extra work ahead. The canard had moved so the holes no longer lined up! Now what? I got my 1/4" drill ready and placed a drill stop on the bit so I could only go deep enough to reach the lift tab insert without damaging it. I adjusted the metal strip to a spot I felt was closer to the correct location. I then drilled one hole down to the aluminum insert. I was just slightly off. Using this I made a small correction and proceded to drill the next hole. It was better but still slightly off. One more small correction in strip placement and I drilled the third hole - perfect. I then drilled this deeper to drill out the silicon but not deep enough to hurt the nut plate threads. I then put a bolt in that hole. This then allowed me to correctly drill out the other two holes. I tweaked them a bit with an X-Acto blade. In the end I had good holes with the minor issue of the 9 layers of BID had a slightly elongated hole. Not a problem since this would get filled with flox. The other insert went a little better. I found the correct spot on the second hole.

Mounted Lift Tab July 3, 2001. After my fun with making the holes I mixed up a little wet flox, smeared it on the lift tab and shear web face and bolted the lift tab in place. I then cleaned up all the excess that squeezed out. I sighted down the canard and both tabs seem to be parallel. That should help in chapter 12.

Shear Web Complete July 3, 2001. Here's a shot of the canard after removing the peel ply from the shear web layup. I have also mounted the lift tabs. The black lines were on the UNI from when I cut it all for the layups. You can see how the center has a darker green color while the outboard looks bluer. I'm using MGS which has a lovely green hue to the hardener. The more layers, the darker the green - obviously. This layup was a pain. It took me six hours to micro the shear web, apply all the glass, add the peel ply, and remove the masking tape. It was also 90°F in my workshop - too hot. I was near heat exhaustion when finished. It was very similar to doing the UNI on the main landing gear strut. Some plies went OK and some pissed me off. I even put two pieces on in the wrong direction. Luckily I realized it before I put the next piece on. What a pain to peel the piece off, flip it around, and get it in place again.