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Wing Build - virtually

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  • Wing Build - virtually

    I've been hammered with work and life but got a little work done on the "planning" done.
    I studied the plans and Erb and Newtons works and my build buddy and I decided to build our form blocks and actual parts using a CNC (we have access to a shop with reasonable rates). So I took Drawing 4 and some cussing and I finally completed the main wing in 2D and 3D. I am still working the flight control surfaces, but the mechanisms are complete. Wing ISO.pngFlap mechanism.png
    Attached Files

  • #2
    Wow that's a nice drawing. I see you even got the cables in there. I have only the faintest idea when it comes to CAD. How did you get the original airfoil shape into the drawing?
    4 Place Bravo
    #1624
    Currently making form blocks

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    • #3
      btdobie,

      I took Drawing 4 (the Airfoil drawing) and had it scanned in at a blueprint shop as their equipment won't 'stretch' the drawing in any direction. Then I got a copy of Harry Riblett's book "GA Airfoils" as it explains how he does the airfoil layout (his XY plotting). Tracing the outside edge of the drawing and then using the XY layout gave me a set of points that I could draw a "spline" through which is a flexible line in CAD. I used this airfoil shape and added in both spars, ribs etc.

      It took a couple attempts to get the the scale right using the other drawings on the wing rib/spar layout...but I'm finally happy with the result. I'm trying to finalize the flight controls and then I'll CNC my form blocks for the ribs, pocket ribs, aileron/flap ribs. My build buddy owns a set of plans also so the little extra work with the drafting etc. will pay off when we build where we already worked out the bugs with fit. I decided to take the 2D drawings and make a 3D so I could ensure all the fits of all the parts...basically allowing me to build the wing several times, which helped me understand the build sequence.

      Good eye on spotting the cables...so I laid out everything so I could even CNC the holes in the ribs for the aileron cables, Flap torque tube etc. This way I can form a rib, rivet it to the spars and not have to go back in a fiddle with other work like punching holes for the aileron cable, pitot, or wiring for the wingtip lights etc. The plan is to CNC all the flat parts out with all the electrical, fuel and mechanical cutouts in them, then form them on the blocks and start banging the wing together. We are going to build a test bay of the first two ribs to check our tolerances...if that works its full throttle at that point. I think I've figured out a way to even cut the wing skins and all the rivet holes. We are undersizing the holes in case we have to move a hole. Most larger towns/cities have "maker spaces" that have CNC routers that are accurate enough...so we'll find out! I've done repair parts before like this so I'm confident I can make it work.

      The drawing you see here has .003" gap between all aluminum parts to allow for primer. I added another .004" for the steel to aluminum parts to allow for topcoat on the steel. All the edge distances have been checked and even rivet head clearances. You gotta have something to do while sitting in virtual meetings at work...lol

      We planned on starting back in the summer...but with the plannedemic its screwed up the schedule a tad.

      Andy

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      • btdobie
        btdobie commented
        Editing a comment
        Wow you've really put a lot of thought into this. I would imagine having all the skin hole per drilled would be a huge time saver.

    • #4
      Good morning, Wyo,

      What CAD package are you using?

      All my best,
      Rob

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      • #5
        Rob,

        AutoCad, but Solidworks you can get free with an EAA membership. either work well depending on how exotic you want to get.

        Andy

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        • #6
          Originally posted by Wyo Johnson View Post
          The plan is to CNC all the flat parts out with all the electrical, fuel and mechanical cutouts in them, then form them on the blocks and start banging the wing together. We are going to build a test bay of the first two ribs to check our tolerances...if that works its full throttle at that point

          Curious if you are thinking 1 at a time or going for broke and stacking as much as you can between a backing plate and some top plate?

          Watching 10+ parts come out at once is always nice.

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