Closing out 2023

You think you’re about ready to perform some major step, then you step back and realize you’re not as close as you thought… I thought I was about ready to cut out the aileron, but I still had to get the bottom geodetic braces in as well as several of the plywood stiffening strips that keep the aileron bay and aileron from distorting when the fabric gets shrunk around it. Today I did that, I also got the leading edge plywood wrapped around the rest of the way and glued and clamped in place, and added the last of the wingtip reinforcements along with the gussets for all of those.

I started to shoot primer on the torque tube, but the can stopped spraying about halfway through. Super frustrating, as it’s a full can, It’s been in a cabinet in the garage for a while, so I suspect there was a chunk of unmixed solid that lodged in the valve or something. The spray tip is clear, the can is pressurized, but it refuses to spray. Bummer. I found a can of self-etch primer in another cabinet at home, so hopefully that works. I may end up with a torque tube that’s half gray and half white… oh well.

I’ve been cleaning up the Airpath compass while I wait for the new gaskets and diaphragm from Spruce. This one has a light and I didn’t want to use the incandescent bulb, and I’d already broken one of the wires anyway… so that path was blocked. I had ordered some LED bulbs from Amazon – they are commonly known as type 74 LED bulbs. The spec sheet showed they are about 0.7″ long and 0.23″ diameter. Those arrived today, and they do fit inside the bulb socket. I soldered the wires onto the new LED assembly “backwards”, or with the wires running along the body of the light so the tip goes in first and the connector end faces outward. This puts one of the three chip LEDs directly over the little red window that illuminates the compass. I had to remove about 1mm of the tail end of the lamp assembly so the little cover would close, but with that done it’s near perfect. I’ll get more pictures as soon as the paint I used to touch up the worn spots on the lamp cover is dry. The gaskets are supposed to be here on Tuesday, and I’ve got a can of mineral spirits I can use to fill it… not being willing to spend the extra money on UPS shipping for a pint or so of “compass fluid”, which from what I can tell is basically… mineral spirits.

First wingtip bow

On Monday night we got the wingtip bow put in place and corner blocked. It’s looking very much like a wing now! I also received my order of plywood from Spruce, so was able to cut and glue in the gussets for the compression struts.

Of course there is still work to be done. Some additional bracing needs to be installed for the bow, and the trailing edge will need to be sanded to match the contour of the wing trailing edge. Details, details.

Yesterday I picked up three 12′ long sections of 6061-T6 aluminum tubing. Two of these will become lower wing aileron torque tubes, and the third will become the torque tubes for the upper wings. None of that stuff does not come cheap, I’m telling you. I’ve pretty much blown my materials budget for the month. But, at least now I can continue with aileron construction – once I get back over there to the shop. My darling wife is sick and has tested positive for COVID, so I’m avoiding getting close to anyone for a while just as a general precaution. Once I know I’m not contagious I’ll get back over and get that tube cut to length and resume work.

More left wing work

I’ve been over working on the wing a couple of times since the last post. Stu and I worked out what seems to be the best way to fit the wingtip bow. Yesterday we glued, stapled, and clamped the leading edge plywood to the top of the ribs and the top false spar, but left it at that stage. Wrapping the ply around the leading edge results in the upper edge pulling loose, so we decided to leave it as is and do the rest later on. I was planning on today, but may hold off on that until the wingtip bow is installed — I want to get the corner blocking glued in behind the LE ply, and that may be difficult with the plywood fully wrapped. Don’t know, I’ll need to look at that today.

We spent an hour or two yesterday trying to work out the aileron bits and pieces. The factory cut and drilled plywood bits (CW32, CW34, CW35, etc.) have been both a blessing and a curse. Most of the confusion seems to come from the fact that the CW36 pieces, which attach to the ribs just inboard and just outboard of the aileron bay, are apparently drilled WAY off. The pieces are too long for the wing to begin with — they seem to be sized for a rear spar built with the original 1/2″ thickness. non the current 3/4″. Then there’s a hole marked “more or less” on center, but the actual hole is drilled about 1/8″ or so low, or high, depending on how the piece is flipped. There is no orientation we could find that matches up with the holes drilled in the CW35 pieces that are used to attach the aileron to the torque tube. Fortunately, it really doesn’t matter. I’ll be cutting 1/2″ UHMW end bearings that will attach to those plywood pieces, so we can enlarge those holes as much as needed as long as there’s enough room left to attach the bearing pieces.

What we did get done was to cut and glue in the aileron spar web, and some of the 1/4″ stiffeners before the glue left over from the leading edge ply got too thick to work with. I glued up a test piece with that; the epoxy is a bit thicker than I would normally use, but I may have just been too conservative on that. I can’t think of any reason it wouldn’t give a full strength joint; the test piece will tell me for sure.

For the most part, I’m waiting for my aluminum for the torque tubes to arrive at Millard Metals, and sheets of 1/16 and 1/8 ply to arrive from Spruce. I need the ply to cut gussets for the compression struts, and we don’t want to get much farther into the ailerons without full length torque tubes to keep everything perfectly aligned.

Lower left wing, Day 5

After a couple days’ hiatus for Thanksgiving, I went over yesterday to resume work on the wing. We cut the notches in the nose ribs and got them glued in place, and I cut and glued the corner blocking for the four compression struts. I still need to cut and glue in the gussets for those. We took a look at some of the aileron pieces to figure out how all of that goes together. I’m waiting on a response from Millard Metals on my aileron torque tube stock; I don’t think we can do much until I have that. I think the next step will be to get the wingtip bow figured out, and wrap the leading edge with plywood. Then I could also start cutting and installing the bushings for all of the attachment bolts.

11/11 update

How many mistakes can one man make? Enough… thank God I’m building this out of wood, so things can be fixed!

With enough of the aluminum bits cut and drilled to get the spars drilled, I started laying out the hole locations for drilling. Along the way I found a couple of places where I’d gotten blocking in the wrong places for various reasons. Fortunately, in each case I was able to simply add some well fitted wood blocks to get the support where it’s needed. So far I figure the plane will be about two ounces heavier for the extra wood and epoxy. I can live with that. Still, it’s caused a bit of angst.

As of this morning, the next step is to cut the slight angle on root ends of the lower wing spars, drill the holes for all of the bolts, then start actually assembling a wing. At last.

First Aluminum

Today I picked up some flat bar stock from Millard Metals. The Celebrity wings use fittings of various sizes to attach flying wires, landing wires, N struts, and of course to attach the wings to the fuselage. These are made from 1/8″ and 3/16″ 6061-T6 and 3/16″ 2024-T4. I ordered some 6061 tubing from Aircraft Spruce to use as bushing stock. It will take me a while to get all of the brackets cut and drilled, but I did cut at least one of each piece and marked them for the bolt holes. I’ll drill them with small pilot holes, and once they’re all ready I can start drilling the spars for the bolts to attach them. Once those holes are drilled we can start assembling the first wing. I can install the bushings after the wing is assembled, but the holes need to be drilled first.