Old Mechanix Illustrated Magazine Float Drawings "a bit to tiny"

Discussion in 'Bush / Float flying' started by blane.c, Dec 17, 2018.

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  1. Dec 17, 2018 #1

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

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    Because the float article talked about 550lb to 600lb max for the floats I "assumed" that the 275lbs marked on the float drawings water line was for each float, some arithmetic has revealed that, that is not the case. The 275lb @ waterline includes both floats or about 137.5lbs floatation for each float at the waterline shown. The good news is that the floats if watertight should keep a little over 600lbs from sinking albeit most likely in an inverted position. My math is based on a cubic foot of water weighing 62.4lbs.

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    cluttonfred and wanttobuild like this.
  2. Dec 17, 2018 #2

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

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    I have worked out some "ruff" numbers that "may" work out for sizing, it is not a complete workup but a generalization to work from. The forward section ahead of the step would be 16 3/8" wide, the top would be 8 3/16" radius, the height with the keel omitted would be 13 1/8", the "v" section directly above the keel would be 1 1/2" and the section between the "v" and the horizontal line of the radius would be 3 7/16" (1 1/2"+3 7/16"+8 3/16" = 13 1/8") and from the step to the extreme fore of the float with the keel omitted would be (approx.) 97 1/8". The CB would remain 6" forward of the step and the CG would be at a 10 degree angle (+ or -) from the bottom/aft of the step to a vertical line from the CB in the level flight attitude with the CL on the same vertical line. If you take that forward box and project and enlarge the existing floats forward area to match, the heel of the float will self determine. It's just the math then to make sure it's right. My "ruff" numbers are that it will float 268lbs each float below the enlarged projected waterline which if it "works out" is perfect for me. This will be a float just over 14 feet in total length.
     

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