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making a geodesic airframe

keith_atkissonkeith_atkisson Member Posts: 1
Here's my challenge...

a) I have a 3-5"" torus or +5" hexagon and I need to meld 45 degree X ends , down into the torus or hexagon.

b) Then 4-7 of these Xs are spaced equally around a radius upon the torus or hexagon, and while standing upright at 90 degrees to the bottom plane. It would look like the kind of design that is used on the stools that an elephant is able to stand on.

c) After I get that accomplished, I need to copy this half, invert it 180 degrees, and place the tops of the newly copied design solidly onto the tops of the 1st design, where they will get printed as one, solid unit with a torus or hexagon at each end of the completed model. I also want to bridge each 'X' at their centers or waistlines, with a connecting brace so each X is joined all the way around the circumference. These braces will also follow the same curvature as the XS do in "D' below.

d) I also need all of these X assemblies to curve in the same curvature as the curvature of the torus. Or close to the somewhat-curvature (a given radius) of the hexagon.

e) This design is used on most jet engine casings currently because it provides the utmost strength. Each triangle puts load onto the triangle next to it and they cancel each other out so all the stress and torsion is equally distributed. So you can see this is not my design or something new under the sun. It was made popular in WWll when England used this design in some of their airplanes.

f) If you need more information because I have not been clear with the description, please search on Wikipedia or elsewhere for "geodesic airframe."
Thank you very much for the help as I am new to CAD programs and as I have made my first attempt in Tinkercad, I now need to make a much better model to test out my theories.
Have a great week.

Answers

  • michael_stallsmichael_stalls Member Posts: 51 PRO
    Do you mean similar to the construction of the WW2 British Wellington bomber? I dont quite understand what you are trying to produce exactly....pictures always help! Im an Aero engineer and ive already done a few tube steel trusses like this


    Any way i think a wellington type geodesic structure should be straight forward but a bit more info would be helpful
    cheers
    michael
  • bobtbobt Onshape Employees Posts: 7
    We have some tools in a coming release that will let you do this all programmatically/with custom features. We have done some examples along these lines (single feature space frame trusses, single feature wing ribs and spar lightening holes, build a tubular frame structure for sketch lines etc.) and will post them when these capabilities go public.

    If your need is urgent, let me know and I'll see if you can be added to our Early Visibility Program.
  • michael_stallsmichael_stalls Member Posts: 51 PRO
    edited May 2016
    bobt said:
    We have some tools in a coming release that will let you do this all programmatically/with custom features. We have done some examples along these lines (single feature space frame trusses, single feature wing ribs and spar lightening holes, build a tubular frame structure for sketch lines etc.) and will post them when these capabilities go public.

    If your need is urgent, let me know and I'll see if you can be added to our Early Visibility Program.
    Ohh yesss my need is very urgent!!!.....this would make things so much easier!! Thankyou!!
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