Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Page 1 of 6 12345 ... LastLast
Results 1 to 10 of 54

Thread: Newbie Question

  1. #1

    Join Date
    May 2009
    Location
    Lebanon, Or
    Posts
    35

    Default Newbie Question

    I had a question that is likely somewhere in the forum but as yet I have not found it by searching. Now that the rain has started I can finally spend some quality time on the project! I was working on the aileron idler bellcrank and after removing the powder coating and squaring the tabs to each other I can get the washers and bellcrank installed into the fuselage. The question concerns torqueing the bolt, if torqued to the 20 – 25 in lbs specified for this bolt nut combination the tabs compress binding the assembly. Obviously I’m missing something. I have enjoyed the hundreds of post I've read so far and learned much in the process. Thanks for your input.

  2. #2
    Senior Member Dave S's Avatar
    Join Date
    Oct 2008
    Location
    St Paul, MN
    Posts
    1,833

    Default Re: Newbie Question

    Hi Greg,

    Look at the torque as a limit not to exceed rather than a specification to meet. A lot of A & Ps would not even use a torque wrench in a situation like this......The goal is to tighten the nut so you get the desired effect which is minimum end play on the bearing and no binding while not exceeding the torque limit of the bolt/nut. For a new person it is best to tighten with a torque wrench to make sure the torque limit is not exceeded in the process. This is not like tightening a spark plug or wheel bolt where an exact torque is mandatory.

    You may also find that using thin washers or stacking thin washers might help with getting the fit you want.

    I don't know if you are using a nylock nut or a castle nut with a drilled head bolt; but, the goal is the same.

    After operating my plane for a while I found that I could adjust the tension on items like this (belcranks) as parts wore in.

    Sincerely,

    Dave S

    KF 7 trigear
    912ULS Warp Drive

  3. #3

    Join Date
    May 2009
    Location
    Lebanon, Or
    Posts
    35

    Default Re: Newbie Question

    Thanks Dave. I suspected this but could not verify it with any of the documentation I have access to. Thanks for your response. Greg

  4. #4
    Senior Member Esser's Avatar
    Join Date
    Jul 2011
    Location
    Edmonton, AB
    Posts
    2,048

    Default Re: Newbie Question

    Has anyone switched out the nuts and bolts for a drilled bolt with a castle nut and safety wire?

  5. #5
    Senior Member Dave S's Avatar
    Join Date
    Oct 2008
    Location
    St Paul, MN
    Posts
    1,833

    Default Re: Newbie Question

    Esser,

    Affirmative. Drilled bolts were used for all control rod ends and bushings for N128DD.

    Sincerely,

    Dave S

  6. #6
    Senior Member
    Join Date
    Nov 2008
    Location
    KDKB (Dekalb, Illinois)
    Posts
    644

    Default Re: Newbie Question

    Still on cup 1 of coffee, but isn't this a bolt with a castle nut, and a cotter pin? If so just tighten it until it "feels right", and put in the cotter pin.

    Regards,
    Jeff Hays

    Quote Originally Posted by Sabre View Post
    I had a question that is likely somewhere in the forum but as yet I have not found it by searching. Now that the rain has started I can finally spend some quality time on the project! I was working on the aileron idler bellcrank and after removing the powder coating and squaring the tabs to each other I can get the washers and bellcrank installed into the fuselage. The question concerns torqueing the bolt, if torqued to the 20 – 25 in lbs specified for this bolt nut combination the tabs compress binding the assembly. Obviously I’m missing something. I have enjoyed the hundreds of post I've read so far and learned much in the process. Thanks for your input.

  7. #7
    Senior Member Esser's Avatar
    Join Date
    Jul 2011
    Location
    Edmonton, AB
    Posts
    2,048

    Default Re: Newbie Question

    Mine are all Nyloc but I think I will be switching to castlenuts.

  8. #8
    Super Moderator Av8r3400's Avatar
    Join Date
    Jan 2009
    Location
    Merrill, WI
    Posts
    3,044

    Default Re: Newbie Question

    A rod end bearing only requires a locking nut because there is no movement on the hardware. A cotter pin and castle nut is only needed when the hardware is the rotation element of the joint.

    A rod end bearing should be tightened in it's mating fork such that the ball of the bearing does not turn against the hardware. The ball should only turn in it's socket.

    Using castle nuts on a rod end bearing is not the correct usage of hardware and will result in unwanted wear on the bolt itself instead of the ball of the bearing as it's design intended.
    Av8r3400
    Kitfox Model IV
    The Mangy Fox
    912UL 105hp Zipper
    YouTube Videos

  9. #9
    Senior Member Dave S's Avatar
    Join Date
    Oct 2008
    Location
    St Paul, MN
    Posts
    1,833

    Default Re: Newbie Question

    During the construction of the aircraft, I had three EAA tech counselor inspections. Two of them were done by a person who was a long time Airline A & P (& RV builder), the other was an EAA tech counselor, FAA employee who worked on certification of in service components for transport aircraft. The DAR also liked the drilled bolts. The A & P tech counselor suggested the switch to drilled bolts/castle nuts & cotter keys. What I didn't put in my original post on the subject was the fact that this also included the use of select fitting, as needed, of thin washers to allow the correct tension ("Feels right") and have correct cotter pin alignment.

    For what it's worth,

    Sincerely,

    Dave S
    KF7 Trigear

  10. #10
    Dave Holl's Avatar
    Join Date
    Mar 2009
    Location
    London England
    Posts
    128

    Smile Re: Newbie Question

    Dave
    I did the same on my installation and it's what I expect to see on Boeing and Airbus installations with flying controls
    Dave
    Dave Holl
    Building Kitfox MK7
    Rotax 912ULS

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •