Ch25: Contouring the Canard

[Dust]

my gap is 1/16 OVER plans size, i like oversized gaps, stops any possible movement problems

[Wayne Hicks]

Huh? Please decode. What gap?

[Dust]

All of the control surfaces are supposed to have a gap between the rest of the flight surface or in the case of the elevator inside, the fuselage.

[rnbraud]

Hello Wayne and all,

I am going to finish my Chap. 10 canard this coming weekend. Since the surface finish of the layups on the canard are a lil rough, I definitely want to try out Wayne's wonderful canard contouring tool thingy.

The question is, do I do this now, or later when the canard is closer to installation? It will be a long while before I wil be installing the canard and/or finishing it up and was curious if I should wait til then, or go ahead and "shape" it now while I have the jigs and all.

Thanks.

[Wayne Hicks]

Finishing the canard now is one of those 6 of 1, half dozen of the other arguments:

(1) The "roughness" of the canard won't keep you from continuing the build. If you don't feel like finishing now, press with the build.

(2) The canard is easier to contour without the canard cover in place. However, you'll have to remove some of the micro to get down to the glass when you install and glass the canard cover. Then you'll be filling in and recontouring that small section.

(3) From the math point of view, it doesn't matter if you contour now or wait until later. From the psychological point of view, the more contouring you do now, the less you have to do in Chapter 25. They don't call Chapter 25 "the wall" for nothing.

[Dust]

My canard cover is separate from the canard, part of the forward access hatch

[rnbraud]

Originally Posted by Dust

My canard cover is separate from the canard, part of the forward access hatch

Huh? Interesting. Any pics to look at?

[rnbraud]

Originally Posted by Wayne Hicks

Finishing the canard now is one of those 6 of 1, half dozen of the other arguments:

(1) The "roughness" of the canard won't keep you from continuing the build. If you don't feel like finishing now, press with the build.

(2) The canard is easier to contour without the canard cover in place. However, you'll have to remove some of the micro to get down to the glass when you install and glass the canard cover. Then you'll be filling in and recontouring that small section.

(3) From the math point of view, it doesn't matter if you contour now or wait until later. From the psychological point of view, the more contouring you do now, the less you have to do in Chapter 25. They don't call Chapter 25 "the wall" for nothing.

Thanks Wayne. That's pretty much what I thought. My initial concern was to store the canard and contour later. That way the canard would "stabilize" over time and the contouring would be more accurate at the end.

By stabilize I don't mean major changes, I am referring to the surface not the structure.

Later.

[rnbraud]

Hello Wayne, and all,

Well I haven't gotten to contouring my canard yet, family got in the way.

I am going to try again this weekend.

Just curious, you mentioned you cut your contouring block oversize to account for the thickness of the sandpaper.

If you don't do this, wouldn't the sandpaper just ride a lil higher on the canard while sanding? If not, how much oversize did you cut your contouring block?

Thanks.

[Steve parkins]

the le and te would be cut to short

[rnbraud]

Originally Posted by Steve parkins

the le and te would be cut to short

Thanks Steve. I see the light now.

Then, how much oversize: 1/16", 1/8"?

Guess it depends on the sandpaper.

[Wayne Hicks]

I traced the G template onto the sanding block. Then cut slight outside of the line. By the time you add the sand paper, it's just about right. The trailing edge of the sanding block doesn't match the T.E. of the canard. I think I cut in an extra gap of about a quarter inch on purpose. If the sanding block were an exact fit leading edge to trailing edge, you wouldn't be able to slide it back and forth without the block "locking up" and jamming.