11.3.0 Canard Tips

The first step is to cut a 3/4” deep slot in the edges for the tips. The tips have a slightly recessed edge which fits into that slot. You can see the slot in the photo below.

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Cutting a slot for insertion of the canard tip.

I haven’t checked the canard for level since back when I first built it. In order to get the tips level I also need to make sure that the elevators are level and aligned properly. I reinstalled them to check and sure enough, they were slightly out of whack. I corrected that, then used that string you see in the photo to help check the alignment.

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Here’s a side view that better shows my string level. If the canard is level, which it is, and the string is level, then that means that the edge of the tips are level. This was an initial check. Once I epoxy these into place I’ll be double-checking level again. I only have one chance to get it right! In addition, the elevators also need to be aligned properly. This is yet again another one of those 3D puzzles that make building this airplane a challenge!

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Making sure that the tips are at the same height and that everything is level!

The manual warns that there may be a leading edge gap. The tip alignment is actually done with the trailing edge of the tip and elevator. Well, sure enough, the right side tip has a gap. The factory pre-makes these tips and after measuring both of them, it turns out that this one is a bit shorter than the other one, which does not have a gap. So, after this is glued into place, I’ll have to fill that gap as a part of the finish work that I need to do for the canard.

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Nice gap! According to the manual, this is not unusal. The gap gets filled during finishing.

These tips also need to be reinforced with a rib. I traced out the shape using the tip itself as a guide, then cut it out. I’m using Divinycell foam here that already has one layer of fiberglass on both sides. This is leftover scrap from when I made the fuel tank bulkheads. Never throw away any leftovers! This saved me from having to pre-cover the Divinycell!

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Rib stiffeners need to be construction and installed inside of the tips. Here is one of the ribs.

Here I’m test fitting one of the ribs in the tip. Only the exposed part of the tip needs the rib since the canard supports the leading edge part. this also helps to enclose the tip from the elements.

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Test fitting the rib. Looks good!

You can see the small end cap attached to the rib. This rib is now hot glued into place in preparation for a 1 BID layup that wraps around the entire rib. 

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The rib is not hot glued into place awaiting a 1 BID layup to lock it in.

Before installing the tips I need to re-check the canard to make sure it’s level on my work surface. It looks pretty close to me.

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The tips must be level with the canard itself. I’m using a string line here to check that the tips are level with each other. You can also see in the photo above that the string itself is also level with the canard. In addition, the ends of the tips need to align with the trailing edge of the elevators.

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The tips must be level and align with the elevators.

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And here's the left side tip alignment.

So, once everything is aligned, it’s time to permanently mount the tips to the canard. That’s actually now finished. Once they are glued into place with structural epoxy, a single layer of BID is laid up across the joint between the canard and the tip. The next step is finish work, which I am working on right now. More photos of that later.

ui© John Trautschold 2018