Chapter 13.2 - Nose Top and Canard Cover
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Step 10: Nose Top and Canard Cover:
As I started dealing with the foam for the Canopy Frame in Ch 18 around April 2016, I wanted to get the flow nice all the way from the nose. So I stopped on the canopy and addressed the build up of the Nose Top and Canard Cover (sides and bottom of the nose were done previously David, see previous documentation). This began with finding the last of the big blue wing foam that I like working with and were included in the project, when I bought it from David Pierce. I then started working on building a shape guide for the nose top. Rather than make side templates as Wayne Hicks and Bernie Siu did, I decided to use a bending beam class of shape by cutting some 1/8" masonite and trying some weights on it in front of F 0 and on F28 to closely match the slope at F 0 while allowing a smooth transition to almost straight at the canopy intersection (where I'd previously marked with tape for the 3/4" bonding edge). See the picture to the right for the shape I decided on and marked into the foam block for the Right side of the nose. I then marked this profile on the outboard side of the block, numbered it for hot wire cutting and got my son Reece to help me hot wire the shape in. I then used this piece back on the nose to mark the Left side block and hot wire cut it identically. I needed some extra foam at the shoulders over the canard so all these were micro'd together along eventually with some spacer foam strips to get good gap filling with the uneven top surface left over from the nose side wall construction. Then I was ready to start shaping with a little hot wire work but mostly: straight hand grater, 80 grit on belt sander, and 80 grit on sanding block, and eventually 100 grit on sanding block... A big lesson was only sanding while I had good physical coordination and mental focus. I found out the hard way what happens when I pushed myself to keep shaping when I was a little tired or getting less attentive by having the block slip from under the sand belt and gouge the top foam right in the visible flatter area. It's not a big deal at all structurally but it's an ugly reminder until it gets micro'd just before glassing, of not paying very careful attention to the job and the self while doing this work. I also found that coming back fresh to look at the sanding work really helped me see things better and where I could continue to make the shape more smooth each time. i don't have a good picture of it, but I spent quite a bit of time getting a good contour in the underside of the canard cover to match the Canard top profile. I used the Canard profile templates from the full scale drawings and hot wire to get this very close, then finished with sanding. This is important so that later when the canard cover is bonded to the canard (see further below) you don't need much micro. You also need this fit good before finishing the top profile, so you can just rest the foam on the canard while shaping and know it's not going to sink or require prop-up later. |