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Landing Gear Door Optimization

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  • Landing Gear Door Optimization

    The first pic below shows the beautifully molded cavity for the landing gear doors on the Choco Fly ASW 17s. Seeing this inspired me to do something similar for my Baudis ASW 22. Rather than a molded seal I opted for one fabricated from .015 GRP plate like Dean Gradwell had done to his ASW 22. The strips of GRP are 7mm wide and simply glued to the gear doors using medium CA. Normally it would be better to glue the strips to the fuselage instead of the doors but on my plane if I had done that it would no longer be possible to remove the door hinge pins. Time will tell if it will hold up but it seems to work fine for now, partly because the doors only have to open about 75-80 degrees to allow the landing gear to extend.

    In the bottom left picture the small wooden ramp on the door to the right is needed to insure that door always closes after the other door which has the center seal on it. The extra piece of GRP on the door to the left prevents the landing gear from snagging the edge of the GRP.

    The round metal objects mounted in the rectangular plywood strips at the front of the doors are magnets which are used to help insure the front edge of the doors fully close. There is a similar magnet CA'ed to the door as can be seen in the center bottom picture. They are 3/16" diameter by 1/16" thick. Magnets are an excellent way to insure the doors completely close because they don't require more force from the retract servo to open the doors. At the point in the retract travel that the doors are opening the wheel is essentially in free fall and once the doors open the magnets no longer exert any force on them. Why didn't I think of this 15 years ago?

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    Last edited by RickS; 05-12-2020, 08:03 AM.
    Rick Shelby
    Team Horizon

  • #2
    Good stuff, like the magnets idea up front.
    Aviation Concepts rc


    • ARUP
      ARUP commented
      Editing a comment
      +1 and the 'ramp' is key! Nice work!

  • #3
    I'm going to try making the molded recess on the 1:2 AS-33, so I may mold the seal to the door, or use a flexible silicone gasket, like a shower door seal.

    For the hinges, I've found the Schambeck offset hinges work well, and I carry them in stock - see pics.

    Click image for larger version

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    • #4
      The magnet is a great idea! The metal wire that keeps the doors from sticking to the tire has come off my landing gear. I have tried replacing it but it comes off or bends and causes problems. Is there any way around the metal music wire in front of the tire to prevent the doors from sticking (other than servo actuation)?
      Last edited by pete914; 05-16-2020, 04:57 PM.