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4 place front door weight

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  • 4 place front door weight

    Has anyone weighed their front doors? (Upper and lower combined) I’d be interested to know.

    I completed one of my seaplane doors and it’s heavier than I expected. It “felt” fine up until I added the acrylic. Each door now weighs 11 lbs which I think leaves a lot of low hanging fruit for a weight reduction. I think by going to carbon fibre tubing a lot of savings could be made. Also with the latching mechanism, which is where I suspect I’m getting additional weight from.
    Nev Bailey
    Christchurch, NZ
    Builders-log
    YouTube

  • #2
    When I completed my gull wing doors with the carbon fiber frame and the Lexan installed, they weighed a bit over 8 pounds each.
    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

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    • #3
      My upper and lower door frames weigh 5 lbs combined, unfinished. That is the upper and lower for one side. I think I can cut that about in half using aluminum or carbon fiber, and I am going the aluminum route due to cost/benefit over carbon. But the glass is the heavy part.

      I weighed my skylight stuff (not including the aluminum strips on top). it weighed about 14 lbs, The 1/8" lexan was well over half of that, I think it was 8 or 9 lbs. If you use the same thickness the seaplane door glass will be about 6 lbs.

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      • #4
        Polycarbonate and acrylic are heavy, that’s where most of your weight is. I’d bet I could remove close to 50lbs if I removed my skylight, big rear windows and full glass seaplane doors. But I’m not going to, the visibility is worth it and then some.
        Scratch Built 4-place Bearhawk. Continental IO-360, 88” C203 McCauley prop.

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        • Battson
          Battson commented
          Editing a comment
          My thoughts exactly

      • #5
        I used 1/16" Lexan for the skylight, and 1/8" for the doors.
        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

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        • Nev
          Nev commented
          Editing a comment
          Rob are you happy with your skylight? Is the thickness sufficient?

        • robcaldwell
          robcaldwell commented
          Editing a comment
          So far, so good! No cracks. I used acrylic drill bits and over sized my holes.

      • #6
        Don't be tempted to go thinner on the acryllic in the large front windows / doors. It drums like a speaker and nobody likes it. We had to change the windows in ZK-FHR for this reason. A little over 3mm was the thinnest we could go (1/8", same as Rob), 2mm was no good at all. Passengers hated it.

        But yes, it's very heavy.

        Bob's fabric doors are the lightest way to go. But ultimately, a few extra kgs for great visibility - I mean - that's the whole point of going flying, good views

        A idiom, you could save a lot more weight by building a smaller plane - but that's not the point of having a plane.

        My point is, sometimes weight is necessary.
        Last edited by Battson; 06-10-2021, 05:23 PM.

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        • #7
          I have to agree. The only things I am adding weight intentionally is visibility and easy to work on. I hate driving a car I can't see out of. A skylight was a no brainer

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          • #8
            Originally posted by Battson View Post
            My point is, sometimes weight is necessary.
            “Light as possible, heavy as necessary.”
            Scratch Built 4-place Bearhawk. Continental IO-360, 88” C203 McCauley prop.

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            • #9
              Hummmmmmm.....I played with sheet acrylic products in the previous century as a pre-teen in junior high school.

              If you could join acrylic so that the two pieces weld into an optically pure single piece using a cement that is so viscus that capillary action sucks it into a joint.....then it seems to me one could engineer a window/door the is lighter and stronger than a single thick piece and and yet resist drumming. Beefing up the parameter where fasteners attach might seem prudent as well.

              I could do it then....maybe this was the stuff we applied to a joint.

              https://www.tapplastics.com/product/...lic_cement/130
              Brooks Cone
              Southeast Michigan
              Patrol #303, Kit build

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              • Bcone1381
                Bcone1381 commented
                Editing a comment
                .....an acrylic joint.
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