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Howdy folks, I have a question you may be able to help with. I'm working on the sheet metal that encloses the aileron cove, and trying to figure out the best way to do it. In the plans, it's made of three pieces, a top and bottom which I think are meant to be glued on, and then a middle piece attached with PK screws. For those who've built this area, what do you think of attaching the middle piece with screws? It has always looked tenuous to me, and it's getting worse as I try to actually make the parts. PK screws into .020" sheet just seems like a terrible idea. I suspect it's specified that way to provide a way to get to the aileron pivots, and because rivets would be impossible to drive, once the top and bottom pieces are glued on. And PK screws are much lighter than the other choices. How did you end up doing this area? Did you attach that center piece with screws? Rivets? Provide any backing material on the tops and bottoms for the screws to have more thread engagement? Use rivnuts? Something else entirely?

Has anybody ever mounted a Catto carbon-fiber spinner? I bought one for my project and am getting ready to cut it. Two questions: Catto sends 20 screws with the prop for mounting to the bulkhead. This seems like a lot relative to what I’ve read. But maybe I should use all 20 because of the carbon fiber. Thoughts? Second question: Spinners are expensive and cutting them is nerve wracking. You can see in the pictures below how I’m lining up the prop slots. Are there any suggestions as to how to get the cut absolutely, positively correct? It seems like it would be very easy to miss on one side and end up with a lopsided cut. (The white patches on the spinner are epoxy, microsphere slurry for filling in some gaps. I got the unfinished version for painting and it came in pretty rough. Catto says to fill with Bondo or epoxy slurry. When Catto says unfinished, they mean unfinished.) Thanks

I'm ready to fab the tank for the upper left wing and am interested in how people laid this out on their own projects. It looks to me like the effort will include 2 side pieces, a bottom piece, and a top piece. The side pieces will be largely responsible for shaping the contour of the tank. I won't be doing the welding myself but I will be taking the fabbed pieces to the welder. Any pictures or suggestions?

I'm getting ready to make my wing tank forms and have a few questions just to make sure that I properly understand the plans and what has worked in the past: 1. It looks to me like the tank just rests on top of the spars (with pads) and is held down by a single strap. Fabric is run directly over the tank. Is this correct? 2. My best guess, is that the tank should fit as snugly as possible without being a force fit. This is both across the spar tank supports and between the ribs. Is this right? If something is loose I can always pad it in. 3. What about the bottom? Should the tank bottom clear the 1/8 ply? I'm guessing so since the tank appears to be supported primarily by the flanges on the front and back.

I'm putting the spar butt brackets on my top wing, and realizing i may have caused myself some trouble. The bracket is taller than the spar, so there doesn't seem to be a good way to locate it without causing problems down the line when I want to make a fairing for the top wing centerline. I located the bracket so it's centered on the spar centerline, but that puts the lower rear leg of the bracket nearly 1/4" proud of the spar surface, which will make for an almighty bump in the fairing. How did you all deal with this problem?

In putting my aileron together, I've discovered that the brace (-351) and its matching washer both poke below the bottom surface of the spar by about 3/32". Everything is per plans (part sizes, hole placement, etc), as far as I can tell. I've attached a picture showing the problem. Is this something you'd trim off, or do you leave it, and there's some future covering step that makes it irrelevant? -- Composed and sent by Morse code He/they

I'm putting together my first wing panel, the upper left. I've got the ribs on, the wedges glued in, compression tubes installed, and am now working on the drag wires. I see that on two of the ribs (#4 and #6, counting in from the wingtip), the drag wire rubs on a rib diagonal. If I shift those ribs 1/2" or so off their intended location on the spar, this eliminates the rubbing. If I leave them in place, they slightly deflect the wires (I'm using 3/16" 4130 rods rather than the strips specified in the plans). I've seen other folks cut away a section of the offending diagonal, and add a brace below or above the missing section, to reinforce it. Neither solution seems optimal, but I'll have to do one or the other. I imagine that using drag strips, the interference would be even worse. What have others done in this situation? -- Composed and sent by RTTY he/they

I'm working on assembling my first wing, starting on the upper left wing. I've got the ribs on the spars, and am currently working on sorting out the wedge blocks. I haven't yet made any permanent changes, but I'm getting close. One problem I've run into is that the forward cabane fitting doesn't quite fit. The issue is that the forward wedge, when set to the correct thickness-of-spar width, doesn't lift the entire bracket off the spar. The lower corner of the bracket impacts the spar before it can move far enough inboard (red arrow in this picture, and off-center marker is visible through the larger central hole): http://obairlann.net/reaper/aviation/biplane/buildlog/images/20201225_194642-mod.jpeg It looks like the correct solution is to make a new bracket that's a bit wider, to allow the wedge block to slide further inboard, picking up the whole width of the bracket rather than leaving part of it to hit the spar. The other solution, which seems much less good, is to cut into the spar a bit to allow the bracket to move inboard, but I am loathe to impinge on the spar if at all possible. Making the bracket wider would have a relatively simple knock-on effect, which is that the cabane attach point would have to be made longer. Presumably I would want any extra width to be taken up equally forward and aft of the spar's centerline, so as not to introduce any offset stresses at that point. Has anyone else run into this problem? Everything I've done is exactly per the plan, so I'm guessing I'm not alone here. What did you do to address the issue? Is there anything I'm missing? Here's where the cabane fitting detail is shown: http://marquartcharger.org/plans/Sheet%2006%20-%20Upper%20Wing%20Fittings.pdf You can see that the plans and my photo don't quite match, as far as how much of the bracket the forward wedge is lifting. It's close, but it looks like the plans don't have the edge of the bracket cutting into the spar, whereas mine would require that. The cabane details are here: http://marquartcharger.org/plans/Sheet%2021%20-%20Wing%20Strut%20Assembly.pdf Thanks for any help you can offer. -- Composed and sent by RTTY he/them