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Aluminum prop help

  1. Feb 17, 2007 #1
    I had this posted in the wrong forum...srry :blushing:

    I need to contact who ever would be authority on propeller design and applications.

    In short, the Idea is to build a Aluminum prop, 1.2 meters diameter with weight of about 1000 grams. Targeted application would be primarily for powered para gliders. I need some arguments for and against before it leaves blueprint stage.

    If you can point me in the right direction as to who the best contact for me would be, I would be ever so grateful.

    If any of you have experiance on the issue, comments are more than welcome.
  2. jcsd
  3. Feb 17, 2007 #2


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    There are a lot of "depends" comments to be made here. What thrust? What RPM? What other loads are you expecting? What kind of stiffening are you using? Have you done ANY load analyses yet? etc...
  4. Feb 18, 2007 #3
    - Operating @ 2500 rpm
    - Should test to 3800 rpm.
    - Continuous profle design
    - Material Al alloy 6061-T6
    - generating thrust 550n (54 kg)
  5. Feb 18, 2007 #4


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    OK. That's fine and all. However, how can anyone who has never seen what it is you are doing to tell you if it will work? That's YOUR job. You give extremely vague details. You give no decription of the design. You give no layout showing how you plan to assemble or build this. You give no reference on how you plan to reinforce it and where. What details you have given us are about as useful as what the color is going to be. Like I asked before, have you done ANY structural analysis on this design?

    Instead of asking broad, unanswerable questions, do your own analysis and ask SPECIFIC questions regarding that analysis.
  6. Feb 18, 2007 #5
    wood good old tree stuff
    works better in that size
    eazy to work and cheap

    as an alloy prop will need to be hollow
    to get a good foil shape at that weight
    costly and hard to make

    carbon fiber over foam core may work
    if you hate wood
    but cost is a lot more
    for very little gain

    stika spruce is the cheap eazy way to go
    and has been used for years
    and fun to work with
    and requires common tools to shape
  7. Feb 18, 2007 #6


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    Some jet engine fan blades are designed this way. FWIW I spent several years writing software to do the stress and vibration analysis of them, since at the time the commercial programs (NASTRAN, ABAQUS etc) wouldn't do the job - they will do it now, but it ain't straightforward.

    Unfortunately for you, that work was and still is a commercial secret - so don't ask for details!

    FWIW it's no secret that the fan blade material was titanium not aluminum, and the manufacturing technique we used (eventually) was superplastic forming.
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