Trailing-link landing gear

Discussion in 'General Experimental Aviation Questions' started by cluttonfred, Dec 10, 2017.

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  1. Dec 11, 2017 #21

    cluttonfred

    cluttonfred

    cluttonfred

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    I suspect that the rubber disks in compression provide some friction damping as they are squeezed and bulge out against the shaft on which they are mounted.
     
  2. Dec 12, 2017 #22

    Tiger Tim

    Tiger Tim

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    Hey Matt, with your general trend towards simplicity why lean towards making a complex structure like a trailing link landing gear leg? I mean, spring gear is just so simple.

    The only real reason I could think of to go with trailing link on a light and simple homebuilt airplane would be if there was something already commercially available that could be easily adapted. I wonder how much airplane could be landed on a pair of Vespa forks?
    [​IMG]
     
  3. Dec 12, 2017 #23

    cluttonfred

    cluttonfred

    cluttonfred

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    I suspect that a pair of complete scooter forks would be far too heavy for aircraft use. My though in using trailing-link gear is that it's something more easily fabricated from stock metal tubes and angles and plate rather than custom-ordering from somewhere like Grove, where two-seater gear runs $1,500 and up.
     
  4. Dec 12, 2017 #24

    Lucrum

    Lucrum

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    Can't help with any simple examples
    But I too have always liked trailing link gear
    Especially during touchdown
     
  5. Dec 12, 2017 #25

    tspear

    tspear

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    Matthew,

    I think the plane you are planning on has a very low stall speed. Trailing link is great for high speed and large energy absorption. With a low stall speed, I would go super simple and copy Mooney with a simple rubber donuts. That is all, everything else adds weight and weight is the enemy in this kind of plane.

    Tim
     
  6. Dec 12, 2017 #26

    cluttonfred

    cluttonfred

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    I have also considered trailing-link gear using simple bungee wraps or loops in tension by extending the trailing arm forward of the hinge point.
     
  7. Dec 12, 2017 #27

    Vision_2012

    Vision_2012

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    gear legs.jpg

    Vision tricycle main gear.
     
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  8. Dec 12, 2017 #28

    cluttonfred

    cluttonfred

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    Very nice, Vision_2012. How is the gear attached to the spar?
     
  9. Dec 13, 2017 #29

    Victor Bravo

    Victor Bravo

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    The acceptable amounts of drag, weight, rate of descent, and landing speed for any given airplane will pretty much drive the choice of landing gear style. A huge slab of spring steel used as a leaf spring (original Cessna 100 style) will be the lowest drag, probably the highest weight, and the least maintenance. If you are concerned about weight on a slow light airplane, the old Cub style bungee system will be the lightest, highest drag, etc.
     
  10. Dec 13, 2017 #30

    tspear

    tspear

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    But with such a light/slow plane, why not the simple Mooney donuts?

    Tim
     
  11. Dec 13, 2017 #31

    cluttonfred

    cluttonfred

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    For wing-mounted gear, I can definitely see something like the Vision gear posted above working out very well, though I would be thrilled to find something like an adjustable scooter rear shock (example for Yamaha below) light and strong enough to just bolt in. I have also mentioned before that there are hundreds of ready-made, urethane, automotive suspension bushings (example below) to choose from that could be adapted for use in landing gear. If it could be done without welding, just bolting together CNC gussets and strap and square tube, so much the better for reducing costs and encouraging first-time builders. Mike Fisher's Cub-style gear used in many of the Fisher Flying Products aircraft (well-used FP-404 gear below) was entirely bolted together, no welding at all.

    1000-1070.jpg suspension-bushings-science-urethane-bushings.jpg FP-404 Landing Gear Large.jpg

     

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