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  • 30 second light box

    Someone may have had this idea before, but my quick search didn't immediately return this exact method. I call it the 30second light box because that's all the time you need to build it.
    Materials
    -empty cardboard box
    -trouble light
    -piece of glass/acrylic/polycarbonate (whatever you have laying around) slightly larger than the box

    Assembly
    -put trouble light on the box
    -put glass on top of box

    That's it.

    Used it to trace the full size aileron and flap nose rib drawings today and it worked fine.
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    4 Place Bravo
    #1624
    Currently making form blocks

  • #2
    Great idea! Fast and easy!
    Rob Caldwell
    Lake Norman Airpark (14A), North Carolina
    EAA Chapter 309
    Model B Quick Build Kit Serial # 11B-24B / 25B
    YouTube Channel: http://bearhawklife.video
    1st Flight May 18, 2021

    Comment


    • #3
      A little smaller version that I used a lot to make all of the plate fittings...about 8x10: http://www.mykitlog.com/users/displa...203606&row=131

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      • #4
        Here is another method.

        I made a pdf file of my plans using my iPhone and an app called Cam Scanner. I then sent it to my computer using Airdrop.

        A screen shot of the fitting can be printed but the proportions might not be quite right. I print it a few times, adjusting the scale each time so the copy is identical to the actual size of the part. 3M Spay Glue attaches the right sized copy to aluminum sheet, then its cut oversized, bent, drilled and filed to size. (in that order...always bend it first, drill it next. ask me how I know.)

        As I wrote this, I thought we might call this process "Computer Aided Design for Dummies"

        It also might be more time consuming than your light box.
        Brooks Cone
        Southeast Michigan
        Patrol #303, Kit build

        Comment


        • #5
          Bcone1381 not to go off on too much of a tangent here, but when you say not to drill before bending, are you referring to the balance tube holes?
          4 Place Bravo
          #1624
          Currently making form blocks

          Comment


          • #6
            The balance tube holes.......Hummmm.... in the aileron ribs....ummm... I was not talking about them. I think fabricating the balance tube holes might better off done before bending, but I'd try one and see how it works before doing all of them.

            I am referring in general to the fabrication of sheet metal parts and the placement of those parts in an assembly.

            Cut oversize, THEN bend, Then drill, then bring it to final size. Aileron hinge angles is one example.

            Another example, I just made a door skin for the second time. If I had cut it oversize, then put the 90 degree bend in it before match drilling the holes to the skin, then the bend would have been snug to the steel tube frame and perfectly positioned for match drilling.

            Instead I match drilled everything and then tried to put the bend in it. Well, trying to precisely place a bend within .020" is possible, but a rookie like me will mess it up 9 out of 10 times even if I use test pieces. Which I did, so I made it a second time following that rule...
            Last edited by Bcone1381; 09-24-2020, 09:34 PM. Reason: Clarify
            Brooks Cone
            Southeast Michigan
            Patrol #303, Kit build

            Comment


            • svyolo
              svyolo commented
              Editing a comment
              I thought about that with the context being kit manufacturing. Vans has everything "matched hole". My assumption is they have to bend first as well, but I don't know for sure. My career was flying them, not building them.

            • Bdflies
              Bdflies commented
              Editing a comment
              My experience in CAD/CAM shops is that everything is punched and cut, then it’s bent. The machines are so accurate that punching after bending wouldn’t help and would only slow the process.

          • #7
            Ok that makes sense. My mind automatically went to bending rib flanges so I was trying to figure out how holes in the rib would affect that process.
            4 Place Bravo
            #1624
            Currently making form blocks

            Comment


            • #8
              Originally posted by btdobie View Post
              Someone may have had this idea before, but my quick search didn't immediately return this exact method. I call it the 30second light box because that's all the time you need to build it.
              Materials
              -empty cardboard box
              -trouble light
              -piece of glass/acrylic/polycarbonate (whatever you have laying around) slightly larger than the box

              Assembly
              -put trouble light on the box
              -put glass on top of box

              That's it.

              Used it to trace the full size aileron and flap nose rib drawings today and it worked fine.
              ..I love your idea... keep em coming

              call me lazy...

              but I use the sliding glass doors to the backyard ...when the sun is out...you don’t even have to wait for the sun...just as long as it’s bright out...you got a 3 foot by 7 foot light box area... just tape the plans to the glass and go to town...any window will do if it’s big enough

              i have to give credit ... I stole this idea from a cozy mk4 build manual
              Last edited by way_up_north; 09-28-2020, 04:01 PM.

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