FES actual thrust for self lunch

Discussion in 'Electric Propulsion' started by opcod, Jul 22, 2019.

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  1. Jul 22, 2019 #1

    opcod

    opcod

    opcod

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    Hi
    We see many glider with the FES ( front electric sustainer) The low weight one, like the Silent and Lak can take off with the fes system over their 20kw/22kw engine. But what is the actual thrust that this give ? The 1meter prop is quite small.
    Anyone have data of a glider running the FEs at full speed and a fish scale to measure the thrust at the other end .. ? Like a static test or so..

    Thanks
     
  2. Jul 22, 2019 #2

    emir_82

    emir_82

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    Onlye Silent and Lak take off because propeller clearance. The others would but the lower landing gear does not allows it.
     
  3. Jul 23, 2019 #3

    Basil

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    New Lak17C self launches. Has a taller undercarriage and a slightly bigger battery pack.
     
  4. Jul 23, 2019 #4

    opcod

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    Indeed, prop clearance is enought. But what is the thrust given by the fes blade ?
    I guess is under 200pounds .. and over 70lbs ...
     
  5. Jul 23, 2019 #5

    proppastie

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    here are some static thrusts for Xoar propellers I just found ......probably there will be a listing for 1M out there somewhere, in any case you might get an idea of what is needed.
     

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  6. Jul 25, 2019 #6

    opcod

    opcod

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    No this not make much sense as the max prop speed is 4500rpm. So with your chart you max out at 6kw... and calculation look to give that too. That will never take off as it's about 20kw for max on takeoff with fes... Or we miss something in..
     
  7. Jul 25, 2019 #7

    proppastie

    proppastie

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    most likely a different prop. If you know it is 20kw that should equate to a thrust depending on the efficiency of the prop......
     
  8. Jul 25, 2019 #8

    emir_82

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    If those are drone propellers they are optimized for hovering and not to go at 90km/h. They are also optimized to the typical electric motor rpms.
    If you are about to make your own FES system you will need more or less 60kg of static thrust.
     
  9. Jul 26, 2019 #9

    proppastie

    proppastie

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    I found those sheets from so they are paramotor props
     
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