fixed gear vs. retracts

[Karl G. Mueller]

Wayne,

7075T6 should never be used as landing gear. It will fracture
when trying to bend it. A better choice would be 2024T3. This is the
springiest type of aluminum available. Since a lot of suppliers do not
have it as a stock item, 6061T6 is the next best type to use and is readily 
available at most metal suppliers. I have been using legs made out of
1/8" - 6061T6 and had very good results with it. Total weight of the 2 legs
without wheels and pants is 6oz. The gear legs are of the plug-in type and
overlap inside the Fuse. I have one set that has outlived 3 planes and is 
still in use. 
I seen too many carbon gears break on heavy landings (read semi crashes)
and to replace these is not cheap. I buy a sheet of 24"x 48 " and cut the legs
from this. You have to remember to cut the legs with the grain running along the
legs and not across (yes, metal also has a grain to it !). The bend at the
upper part of the leg should be done over a large radius (1 1/4" to 1 1/2" Dia.)
Do not make any sharp bends and the alum. will not fracture.
This works for me.

Karl G. Mueller
kgamueller at rogers.com


  ----- Original Message ----- 
  From: Wayne Galligan 
  To: discussion at nsrca.org 
  Sent: Wednesday, July 16, 2003 11:13 AM
  Subject: fixed gear vs. retracts


     How light is light on the 7075 aluminum l.g. setup?   My setup with Bolly F3A large gear with wheel pants, axles and wheels weights 7.5 oz    I fly off grass and have had no problems with the setup where guys with retracts are constantly fiddleing and tweaking the struts.  The big plus(for me) is set-up.   Easier to build light wings, no linkages, one less servo, sets up in the field in no time flat.   As for tearing it up on hard landing.... just dont land in the tundra.  That is a plus for retracts if you have the gear up, otherwise retracts can tearup a good set of wings if stuck down or if one hangs up or colapses on landing on the runway.  Its a fliers choice.  I have fixed gear on 3 airplanes now and lovem all.  
  I personally like the looks of a nicely setup fixed gear airplane.   

  Wayne G
    ----- Original Message ----- 
    From: John Ferrell 
    To: discussion at nsrca.org 
    Sent: Wednesday, July 16, 2003 8:50 AM
    Subject: Re: Nats photos online


    From this site and personal experience:

    The change to fixed gear on the Prophecy seemed to require less power than those with retracts. 

    It seems to me that the weight is about the same.

    A harsh landing with retracts usually results in needing a little attention on the struts.
    The same landing with fixed gear frequently results in extensive damage to the fuselage.

    There is less bounce with retracts.
    Taxii out is not recomended with retracts.

    Retracts usually provide a wider footprint .

    The wire gear in the pictures on Pastorello's web site looks a little heavy but should be less punishing to the airframe than the fixed aluminum or composite gear.
    7075 Aluminum gear is lighter and more durable than any of the composite gear. Unfortunately, it is harder to work and not nearly as available as 6061.
    6061 aluminum for fixed gear is a waste of time.

    If landings were all scored K4, stif gear would go away...

    John Ferrell 
    6241 Phillippi Rd
    Julian NC 27283
    Phone: (336)685-9606  
    johnferrell at earthlink.net
    Dixie Competition Products
    NSRCA 479 AMA 4190  W8CCW
    "My Competition is Not My Enemy"

      ----- Original Message ----- 
      From: Mike Mueller 
      To: 'discussion at nsrca.org' 
      Sent: Wednesday, July 16, 2003 9:27 AM
      Subject: RE: Nats photos online


       I'm flying with my 1st fixed gear plane (Temptation) this year after many years of retract planes. It's all about taste in my opinion. It's also a fad to have fixed gear now. As far as looks I'll take retracts in the air. I still get a thrill out of sucking up the gears on takeoff. Wheels hanging out of my plane give me the constant feeling that my retracts aren't working while I'm flying. The fixed gears are stronger and allow you to taxi easier ans suppose to increase drag. Either way works well. Mike

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