bending a wing spar

Discussion in 'Sheet Metal' started by quickcut, Mar 21, 2018.

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  1. Mar 21, 2018 #1

    quickcut

    quickcut

    quickcut

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    I am building a 750 cruzer. The main wing spar is too long for my press brake and I would like some input as I would like to stagger bend it(the spar) . By this I mean bend say 15 degrees ,then move the piece up and bend the remainder , increase the bend angle and repeat the process till the whole spar is bent. Comments please, thanks
     
  2. Mar 21, 2018 #2

    TFF

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    You might be able to do it in 5 degree increments. You defiantly don't want to have a point identifiable as the stop start point in the bend.
     
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  3. Mar 21, 2018 #3

    Turd Ferguson

    Turd Ferguson

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    People used to bend spar flanges for legacy aluminum homebuilts and whatnot by hammering the flange over a wooden form block.
     
  4. Mar 21, 2018 #4

    Victor Bravo

    Victor Bravo

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    I thought the Zenairs all use angle extrusions for the spar caps...?
     
  5. Mar 22, 2018 #5

    BBerson

    BBerson

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    You might try hammering the flange while holding down pressure in the press.
    That might avoid pressing a kink at the end.
     
  6. Mar 23, 2018 #6

    Wayne

    Wayne

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    My factory made spar used extrusions.
     
  7. Mar 23, 2018 #7

    Victor Bravo

    Victor Bravo

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    So what do the plans show? Do the plans show a bent spar or a flat sheet spar with angles riveted to the sheet?

    I am confused by all this... what exactly needs to be bent on the main wing spar if you are building a Cruzer?
     
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  8. Mar 24, 2018 #8

    quickcut

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    Your'e right it is extrusion. I just had a quick glance and thought how am I going to bend that.

    thanks
     
  9. Mar 24, 2018 #9

    BJC

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    Isn’t the rear spar bent from sheet?


    BJC
     
  10. Mar 24, 2018 #10

    Turd Ferguson

    Turd Ferguson

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    as is the rudder spar, stab spar.....??
     
  11. Mar 24, 2018 #11

    harrisonaero

    harrisonaero

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    It's not rocket science- clamp and then bend over the edge of a table with a mallet a little at a time. Nothing says it has to be brake formed.
     
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  12. Mar 28, 2018 #12

    proppastie

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    better practice on some scrap....hardened material is not easy to keep straight. if you practice with soft steel it is not the same......you might decide to get it properly bent in a brake....but careful.... most heating air conditioning guys do not know the meaning of the term "bend radius" and you could end up with expensive scrap their machines are usually set up for sharp bends on soft steel.....a "no no"
     
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