{"id":2335,"date":"2008-08-05T09:18:12","date_gmt":"2008-08-05T15:18:12","guid":{"rendered":"http:\/\/www.velocity-xl.com\/blog\/?p=2335"},"modified":"2015-01-29T10:17:30","modified_gmt":"2015-01-29T16:17:30","slug":"6-8-canard-reinforcements-2","status":"publish","type":"post","link":"https:\/\/www.velocity-xl.com\/blog\/2008\/08\/05\/6-8-canard-reinforcements-2\/","title":{"rendered":"6.8 Canard Reinforcements"},"content":{"rendered":"
This entry is part 28 of 42 in the series 06 - Fuselage<\/a><\/div><\/div><\/div>

Now that the elevator torque tube has been positioned, I’m going to get the canard mounts installed. There are a couple steps that the manual has being done all at once. But I’m a little concerned about doing multiple steps at the same time of I’m going to do this separate steps. The first task is to make sure the canard fits in the opening, is level (side-to-side), has the correct incidence (level front-to-rear) and is perpendicular to the centerline of the fuselage<\/span><\/p>\n

The first step is to get the fuselage level left-to-right and front-to-rear. Placing a level on the firewall showed that I was level front-to-rear. Side-to-side level is determined using the center spar (what the wings mount to). The center spar sticks out about 5 feet on either side of the fuselage. But a two to four foot section of the top of the spar is not necessarily representative of the entire span. So first I tried running a string from one end of the spar to the other and using a little bubble level that hangs from the string. But after fussing with that for a while, I kept getting variations. So I gave up on the easy way and used a water level. A water level is a long piece of clear hose filled with water. You put one end of the hose at the end of the center spar and the other end of the hose at the other. When the water level is at the same point of the spar, it’s level. But with one person, there’s a BUNCH of walking back and forth until it’s just right.<\/span><\/p>\n

\n

Looking from the right side, you can see where I have one end of the water level clamped to the center spar.<\/span><\/p>\n

\u00a0\"2008-08-03<\/a><\/span><\/p>\n

Here’s a closeup of the right side. Notice the level of the water is aligned with the top of the spar.<\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

Next, I check the side-to-side level of the canard. First, I used my four foot construction level to get it close. Then I opened the garage door and walked about 20 feet from the back of the plane. Using the top of the right end of the center spar, I raised and lowered my head until I could just see the top of the right end of the canard. Then I looked to the left to check that the canard was the same as the center spar. It wasn’t. So I sanded the bed that the canard sits on one side and shimmed a bit on the other. Then it’s back outside to eyeball it again. After a dozen or so iterations, it was perfect.<\/span><\/p>\n

Looking from the back, you can just barely see the canard above the spar. It looks like a little white line. In fact, you can see a bit more white (the canard) on the right side than<\/span>\u00a0<\/a> you can on the left.<\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

Lowering the camera just a little and now you can’t see any canard… Well, there is just a tiny bit on the far right. <\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

Then I had to check the incidence. There’s a gauge that sits on top the canard and you put a level on that. When the gauge is level, the incidence is correct. So I had to do some tweaking to get the incidence right. But screwed up the level (side-to-side). So I had to fix that which screwed up the incidence. After a while, I had both correctly set.<\/span><\/p>\n

Looking from the fuselage out along the canard. On the top is the “incidence gauge”. When the top of the gauge is level, the canard will be at the correct angle of attack. Resting on top of the gauge is my combination square\/level.<\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

A close up of the level. The front is a bit low (or the back is too high). A little shimming and…<\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

Perfect!<\/span><\/p>\n

\u00a0 \"2008-08-03<\/a><\/span><\/p>\n

Then I had to check that the canard was square to the fuselage centerline. This is done by measuring from the left end of the spar to the left end of the canard. Then you do the same on the right side. Since the spar is square, the two sides will be the same if the canard is perpendicular (it wasn’t). So I had to make some adjustments. Which messed up the two previous adjustments. So I got the side-to-side level, got the incidence right. Then I had to get the side-to-side level fixed (again) which messed up the incidence. Once I got those to right, I had to tweak the perpendicular setting which messed up the other two.<\/span><\/p>\n

Spar\/Canard Measurement<\/span><\/h1>\n

I probably spent about two hours getting this right. And keep in mind that this was just to make sure that I could get all three axis correct. Once I was sure I could do this without any sanding or grinding of anything, it was time for the first major step. The canard rests on the fuselage at the bottom of the opening. I removed some foam from between the inner and outer skins.<\/span><\/p>\n

Left side of the fuselage where the canard rests.<\/span><\/p>\n

\u00a0 \"2008-06-25<\/a><\/span><\/p>\n

I filled the space between the inner and outer skin with a mixture of epoxy, milled fiber (for strength) and cab-o-sil (for thickness). Then I put a layer of thin aluminum tape of the bottom of the canard to prevent the canard from being permanently attached to the fuselage.<\/span><\/p>\n

Now it was time for the hard part. I lowered the canard in place, the epoxy squished out of the space between the canard and fuselage. But now I’ve got the get the canard set correctly. So I spent the next hour or so adjusting, readjusting, readjusting, readjusting, readjusting, etc., etc., etc. It’s a good thing the epoxy takes hours to set up!<\/span><\/p>\n

The following day I was ready to install the canard tab mounting bushings. On the bottom of the canard are two mounting tabs that are the primary means of attaching the canard to the fuselage.<\/span><\/p>\n

These tabs fit up against the “canard bulkhead” which you can see in the previous picture. It’s the part that goes across the fuselage under where the canard sits.<\/span><\/p>\n

One of the canard mounting tabs<\/span><\/p>\n

\u00a0 \"2008-08-04<\/a><\/span><\/p>\n

First I removed and then reinstalled the canard and then checked all the measurements again just to make sure the canard would in the exact correct position… And it was. Then I drilled a 1\/4″ hole through the hole in the tab through the canard bulkhead. Then I removed the canard. I opened up the hole in the canard bulkhead to 1-1\/4″ so the bushing would fit. Then I enlarged the hole in the tab to 5\/16″ so I could fit the bolt through.<\/span><\/p>\n

Then I applied Vaseline to the bolts, nuts, washers and canard tabs. Finally, I reinstalled the canard, coated the bushing with structural adhesive, put the bolts in and tightened the nuts. Then checked the alignments of the canard (again).<\/span><\/p>\n

Right side canard tab.<\/span><\/p>\n

\u00a0 \"2008-07-06<\/a><\/span><\/p>\n

Left side canard tab. The yellow tape under the bolts is my way of indicating which bolts are temporary. In most locations, locking nuts are used. They are basically single use nuts so if you remove them, you should throw them away. In many locations, things will be coming back apart so I use non-locking hardware. This is how I’ll remember.<\/span><\/p>\n

\u00a0 \"2008-07-06<\/a><\/span><\/p>\n

The next morning I removed the bolts, pulled out the canard and then reinstalled it again… And checked the alignment again.<\/span><\/p>\n

Canard bushing in place.<\/span><\/p>\n

\u00a0 \"2008-07-05<\/a><\/span><\/p>\n

Now that the canard is mounted, I needed to get the doghouse to fit.<\/span><\/p>\n

Not very aerodynamic.<\/span><\/p>\n

\u00a0 \"2008-07-06<\/a><\/span><\/p>\n

I used a compass to determine the approximate line to cut on but as usual, I chickened out. I was afraid that I would cut off too much. So I cut a bit shy of the line. Then put it back on, marked it again, took it off, cut a little closer, put it back on, marked it again, etc., etc., etc. And a few hours later…<\/span><\/p>\n

Doghouse in place.<\/span><\/p>\n

\u00a0 \"2008-07-06<\/a><\/span><\/p>\n

Now I h<\/span>ad to build the canard torsion tabs. These are additional layups that prevent the canard from twisting. First, I had to locate on the canard where the inside of the doghouse will be. <\/span><\/p>\n

Here I’ve drawn a line to indicate where the doghouse is. I then sanded down the white filler on the inside. Under where the doghouse would touch the canard, I put down a layer of tape. Then Bondo is used to TEMPORARILY hold the doghouse to the canard. That’s right, Bondo. As in auto body filler. I works great as a temporary means on holding parts together.<\/span><\/p>\n

\u00a0 \"2008-07-13<\/a><\/span><\/p>\n

Then the canard and doghouse are removed as one.<\/span><\/p>\n

Next, I had to build a form for the canard torsion tabs.<\/span><\/p>\n

Canard\/doghouse on the workbench. You can see two dabs of bondo where the doghouse meets the canard. The wood on the fore and aft outboard parts of the doghouse are the forms that create the torsion tabs.<\/span><\/p>\n

\u00a0 \"2008-07-14<\/a><\/span><\/p>\n

Duct tape prevents the layups from permanently joining the canard to the doghouse.<\/span><\/p>\n

\u00a0 \"2008-07-14<\/a><\/span><\/p>\n

Creating a radius with epoxy\/cab-o-sil. Triax doen NOT make sharp turns well.<\/span><\/p>\n

\u00a0 \"2008-07-14<\/a><\/span><\/p>\n

Then as many as six layers of triax are used to create the tabs. Once it cures, remove the forms, sand off the bondo and…<\/span><\/p>\n

Finished canard torsion tabs.<\/span><\/p>\n

\u00a0 \"2008-07-27<\/a><\/span><\/p>\n

Once the canard torsion tabs were done, they are covered with duct tape. The canard is reinstalled back in the plane and wood is used to create a form for the forward and aft torsion tabs.<\/span><\/p>\n

Left rear torsion tab.<\/span><\/p>\n

\u00a0 \"2008-08-05<\/a><\/span><\/p>\n

Left front torsion tab<\/span><\/p>\n

\u00a0 \"2008-08-05<\/a><\/span><\/p>\n

Elevator torque tube cutout.<\/span><\/h1>\n

From the right side looking at the canard installed without the elevator. You can see three of the elevator hinges. But there’s no opening on the fuselage for the elevator torque tube.<\/span><\/p>\n

\u00a0 \"2008-07-19<\/a><\/span><\/p>\n

The first thing is to locate where that hole is supposed to be. Some people eyeball it. Some have used string through the hinge holes. But I got a better idea… LASER! <\/span><\/p>\n

I setup my laser out beyond the end of the canard and adjusted it some that it was shooting a vertical line through the hinge holes.<\/span><\/p>\n

View of the outboard hinges with the laser on.<\/span><\/p>\n

\u00a0 \"2008-07-19<\/a><\/span><\/p>\n

Right side of the fuselage. The center mark is what passed through all the hinge holes. With a pencil, I put a vertical mark where the laser hit.<\/span><\/p>\n

\u00a0<\/a>\"2008-07-19<\/a><\/span><\/p>\n

Then I rotated the laser and repeated with a horizontal line. I put a pencil mark there as well.<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

“X”, or rather “+” marks the spot.<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

Then just to make sure, I changed the laser to a point to re-check.<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

Drill a small hole to get started<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

Then make it bigger<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

Then use the 1″ hole saw for the final opening. You can see the hole on the other side as well.<\/span><\/p>\n

\u00a0 \"\"<\/a><\/p>\n

Since the torque tube is attached to the elevator, I have to cut away the area above the hole I just drilled.<\/span><\/p>\n

Marking the cut lines.<\/span><\/p>\n

\"2008-07-19<\/a><\/span><\/p>\n

After cutting.<\/span><\/p>\n

\"2008-07-31<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

This entry is part 28 of 42 in the series 06 - Fuselage<\/a><\/div><\/div><\/div>

Now that the elevator torque tube has been positioned, I’m going to get the canard mounts installed. There are a couple steps that the manual has being done all at once. But I’m a little concerned about doing multiple steps … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[5],"tags":[],"series":[30],"class_list":["post-2335","post","type-post","status-publish","format-standard","hentry","category-5","series-06-fuselage"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/2335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/comments?post=2335"}],"version-history":[{"count":1,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/2335\/revisions"}],"predecessor-version":[{"id":2370,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/2335\/revisions\/2370"}],"wp:attachment":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/media?parent=2335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/categories?post=2335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/tags?post=2335"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/series?post=2335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}