Sheepdog's Highlander Build-Yep New Posts :)

[SheepdogRD]

Thanks, Wayne. That provides a good illustration.

Take a look at the picture on Brian's page here:
http://www.mykitlog.com/users/display_log.php?user=BrianEwert&project=1909&category=6528&log=125501&row=6

You can see the ridge along the top of the aileron. Where the leading edge should blend into the top surface in a smooth, airfoil-shaped curve, there's a relatively harsh ridge. That tells me air will have a tough time flowing smoothly. I know these aren't high-speed airplanes, but that still looks like a location for inefficient, draggy airflow.

I was thinking of trying to add some additional fiberglass leading edge material to what we get in the kit, or of replacing the fiberglass with a strip of aluminum that extends a little further back. Hmmmm . . .

Dick

[wayira]

Yea, I saw that to. I think I would want that smooth. Maybe some of the experts will add some solution.

[xpflyr]

Thanks, Wayne. That provides a good illustration.

Take a look at the picture on Brian's page here:
http://www.mykitlog.com/users/display_log.php?user=BrianEwert&project=1909&category=6528&log=125501&row=6

You can see the ridge along the top of the aileron. Where the leading edge should blend into the top surface in a smooth, airfoil-shaped curve, there's a relatively harsh ridge. That tells me air will have a tough time flowing smoothly. I know these aren't high-speed airplanes, but that still looks like a location for inefficient, draggy airflow.

I was thinking of trying to add some additional fiberglass leading edge material to what we get in the kit, or of replacing the fiberglass with a strip of aluminum that extends a little further back. Hmmmm . . .

Dick

I just finished mine and thought the same thing. Seems after I was done, it wasn't so pronounced. One thing I did notice about your tapes, ( maybe that wasn't your picture ) I believe you're supposed to put the long ones on last. After the rib tapes are on, over them. Don't see that it matters thou??

edit; this covering thing, first time for me. It reminds me of tape and spackling sheet-rock. You get good at it when you're almost done!

[SheepdogRD]

I tried to find a long 8mm drill for the aileron and flap cable holes in the ribs, but just couldn't figure out a way to get the straight-through alignment I wanted. I finally figured out that I needed a flexible shaft on the drill. Using the flex shaft requires a hex shaft on the bit. We just happened to have 5/16" hex shaft drill bits in standard bit and spade bit.

Some experimentation proved that the spade bit is the right tool. The standard bit gets pushed off course when we're drilling at the edge of the epoxy around the spar, but the spade bit stays right on course. The standard bit drills a nice 5/16" hole, which is a bit too small for the 8mm tubing. But the spade bit it drills a hole that is very slightly oversize, so it's closer to the 8mm size specified.

Here's how the drill, flex shaft and spade bit look:

This setup made drilling the marked holes really simple. All the holes came out fine; I found I needed to go slowly as I reached the back side of the rib to avoid too much splintering of the back face.

The tubes slide nicely into place in the resulting holes with just a little force, ready to epoxy.

[SheepdogRD]

Some builders put back windows in the Highlander, and I want them in this one. One of the objections I’ve had to the usual windows is that they’re just added on externally, so they don’t seal well. At the time I ordered the kit, I didn’t know there was any way to put windows in except to have tabs welded into the airframe, make an aluminum frame to support the Lexan windows, and rivet that frame to the tabs. So I had the tabs built into the kit.

Then Steve Henry built his windows without the tabs. He cut a piece of aluminum sheet the shape of the fuselage tubes, cut the shape of the window out of it, and epoxied it to the tubes. He covered right over it, and cut the fabric out for the window (he glued it to the inside of the frame about 1/2"). Then he installed the Lexan window on the inside, using industrial double-stick clear tape and rivets. It looks very good, and it seals well.

When I was looking at the way the window was going in, I realized I could put in much larger windows much the same way.

I’ve epoxied in an extra piece of .040" aluminum angle on each side, exactly flush with the upper longeron and the stringer; it mounts on the stringer right at the spigot. These angles will be the braces for the panels in which the larger windows are installed. Here's the right-side brace:

I cut a piece of brown paper to fit the opening, took it back off, laid out the shape of the window in it, and put it back in place. Here’s how that looks:

The shape has parallel sides. Although the top and bottom may look parallel in this picture, they’re in line with the fuselage shape, so the window is shorter at the rear.

Across the window, you can see the fuselage tube that most builders have been following. I discovered that this brace doesn’t actually present much of a problem. Because the stringer stands away from the fuselage, that brace is actually inside the window panel just far enough that it won’t rub the window. If the window does bounce against the tube, I'll put a couple of rubber bumpers on the tube to keep it from making noise.

Finally, I cut .025 aluminum to fit the shape. That'll get epoxied in, but not til I cut the window shapes out.

The windows are about 11" high at the front, 9-3/4" at the back, and about 30" long. They'll give terrific rearward visibility, and they enhance the lines of the Highlander.

When the .060" Lexan gets here, I'll get back on this. Right now, it's just an incomplete idea, but I wanted to throw it out for others who are getting close to covering.

[danerazz]

I like it, keep us informed.

Are you putting a window in the turtle deck?

[SheepdogRD]

Are you putting a window in the turtle deck?

So far, the plan is to make the turtledeck completely from Lexan, with Lexan sides. I'll extend the top panel into the area between the standard turtledeck and the flaps, like Keevin Smith did with his. I'm thinking I may want to use a piece of aluminum with a custom angle to connect sides to top, but I bought some Weldon 16 acrylic solvent cement (from McMaster-Carr -- http://www.mcmaster.com), and I want to try it, too.

Going back to the larger rear window, I cut the shape of the window as it is for two reasons: (1) to hide some of the oversize header tank I'll use, and (2) the lower front corner of the window does get pretty close to that crosstube, so I wanted to give it as much ease as possible.

To prove where the crosstube is relative to the window, just put a long straightedge between the top longeron and the stringer, and run it back along them to the second stringer spigot. There's a lot of space except at the lower front and top rear corners.

Another design I considered had the ends parallel to the door post. There's a lot room for imagination.

[taildrgfun]

I did put my back windows in with double sided tape and rivets but the Lexan is on the inside, not outside. I got the idea to epoxy in an aluminum frame from the master builder, Jim Pekola.

[SheepdogRD]

I'll change that in the writeup, Steve.

I've only seen a few pictures of Jim's Extreme Highlander. But you've been kind enough to provide lots of pictures from your build, and I've pored over the details.

Thanks . . .

[Johnny C!]

RD,
That looks great!
I think I was the first one to
do the tabbed window deal,
but I have been so slow building
that some others have already put
idea to the test.
If I ever build another one, I will
definitlely look at your widow frame
design.

Later!

John

[SheepdogRD]

The window surround material I tried to use -- .025" 6061-T4 -- proved to be too thin and too soft; I couldn't keep the cut edges straight with the thinner material. I've changed to .032" 6061-T6, and stepping up in thickness and temper has made it much easier work. I cut the corner holes -- 2" diameter -- with a fly cutter on the drill press:

Then I lined up the edges of the holes with a piece of 3/4" aluminum square tubing, clamped them together, and used a router with a laminate edge-trimming bit to make the straight cuts. After a little cleanup on the Scotchbrite wheel, they're ready for epoxy:

I think I'll cut out and grind down the leftover tab in the middle of the window -- I haven't been able to come up with a good use for it.

[EDIT: When I used the router to cut the window openings, I wore goggles and ear protection, but I failed to consider location. I did it inside, right on the workbench. It threw little tiny aluminum chips everywhere, including clear across the shop. I even had aluminum chips in my coffee. Oops. Next time I'll do that outside . . .]

[JustMaybe]

I think I'll cut out and grind down the leftover tab in the middle of the window -- I haven't been able to come up with a good use for it.

Hang a "Little Tree" air freshener on it. Or some fuzzy dice.

[danerazz]

What do you have going on with your door sills? It looks like you have some kind ov channel over the lower part.

[danerazz]

You also seem to have some tabs on the front sides forward of the doors, they look like they are formed over the frame tubes and extend above and below the tube, or the powder coat is missing from welding, can't tell. Are you planning on removable sides?

[SheepdogRD]

The tabs are exactly what you suggest. I'll take pictures and get them written up.

The door frame has been a months-long project to figure out better-sealing doors, and I finally have something I like. I've made the frames, but not the doors. I've hesitated to write it up until I can say it works, but at this point I'm confident enough that I'll be epoxying the frames in. Then I'll be welding up the doors, which will be similar to standard doors, but of square aluminum tubing. I'll get pictures and a write-up on those posted, too.

Here's an overview: I've made a rail that grips the perimeter of the door frame (just the lower parts -- the top bar is unchanged, and the door still hinges there). The rail squares the round tubing off and holds a "leaf" seal. The Lexan will close on the leaf, rather than on the fabric, and will be inset so the outside of the Lexan will be flush with the fabric. Here's a picture of the frame installed (but not epoxied) and the seal temporarily installed:

Scottie Blankenship's plane was covered already, but we were able to build the first of these systems on his plane. The materials used were different, but the approach is the same. His door frame parts are back from powder coating, and he's about to epoxy them in. We've already cut his door parts to size; after a fit check, he'll start welding them together.

This photo shows Scottie's parts taped into place during fabrication; the outer aluminum ring is the door frame, and the inner ring is the door. The seal, which goes between them, isn't installed yet (and the middle bar of the door isn't in place, either). The Lexan will extend just shy of the door frame, and will be flush with the face of the frame.

There's a lot to do before we can declare a victory, but I think we're on a good path.