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
Results 1 to 4 of 4

Thread: Tracking a Whirlwind

  1. #1
    Senior Member
    Join Date
    Nov 2019
    Location
    Leavenworth WA
    Posts
    613

    Default Tracking a Whirlwind

    I have a 75" Whirlwind three bladed ground adjustable pitch prop on my plane. In checking the tracking, two blades are within 1/16" of each other but number 3 is a little over 3/16" in from the others. I have tried taking it apart and re-assembling it multiple times, moving the blades to different slots in the hub, setting the pitch and pulling forward on all the blades as I carefully tightened down the bolts; all to no avail. Number 3 continues to be out. I have sent a couple emails to Whirlwind with no response (maybe recovering from OSH?) but would like to get some idea if there is something I'm not doing. Any words of wisdom for getting the blades to all track? I've seen specs for tracking that call for plus or minus 1/16" and others that say 1/8". Again looking for some wisdom.

    Thanks

    Gary
    Gary (Geek) Phenning
    Leavenworth (Not the Prison), WA
    Kitfox STi in Building Stage

  2. #2
    Super Moderator desertdave's Avatar
    Join Date
    Jun 2019
    Location
    Scottsdale AZ
    Posts
    304

    Default Re: Tracking a Whirlwind

    Mine does the same exact thing. I have no issues and I think it is just over analyzing the situation as long as it doesn't have any unusual vibrations.
    Dave
    KitFox 6 Taildragger
    912 ULS
    Whirlwind 70” Prop
    Garmin G3x
    All around nice guy

  3. #3
    Senior Member Dave S's Avatar
    Join Date
    Oct 2008
    Location
    St Paul, MN
    Posts
    1,833

    Default Re: Tracking a Whirlwind

    Have to agree with DesertDave 100%

    Reality? The prop blades flex a lot more than that with loading/unloading. The old P factor guarantees there will be a dynamic difference in track from right to left side anyway.

    Not a whirlwind here; but, variations among blades like 1/16" +/- and no unusual vibrations.
    Dave S
    Kitfox 7 Trigear (Flying since 2009)
    912ULS Warp Drive

    St Paul, MN

  4. #4
    Senior Member
    Join Date
    Nov 2019
    Location
    Leavenworth WA
    Posts
    613

    Default Re: Tracking a Whirlwind

    Dave(s) - thanks for the replies. I finally got a response from Whirlwind (think I hit them while they were all at OSH maybe). Here's what they said.
    "Did you have a vibration after you set the blade angles? Blade track is something you look at only if you are having an issue with a vibration. Our tolerance on blade track is up to 1/4". Priority one is to set your propeller blade angles all the same, and achieve your target static RPM. Don't make adjustments base on blade track unless you are having some sort of problem."

    I am still a bit out of that 1/4" tolerance (by 1/16") but my blades are set to where my static RPM is 5330. I took my time setting them and they have a 0.1 degree total spread between them so think I am good there. I put a DynaVibe on the prop and balanced to .08 at 3500rpm, .03 at 4000, .02 at 4500 and .03 at 5000. The comment about the blades flexing I think is right on so with those vibration numbers, I think I am OK.

    Again - appreciate the responses.

    Gary
    Gary (Geek) Phenning
    Leavenworth (Not the Prison), WA
    Kitfox STi in Building Stage

Posting Permissions

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