MK Dual Elavator Bellcrank & Pushrod?

[Brian Billings]

Speaking of the CF push rod set ups, I would like to share a little info. I just finished installing my second CF. elev. pushrod assem. in a Impact, the first was in my Majestic. In the Majestic I got the DEPS setup from CST seen here http://www.cstsales.com/CCPush-rodKits.htm
This kit comes with a thin walled Teflon outer case and even with a slight bow or arc in the assem. the system remains Very friction free.
For the Impact I purchased the kit from Central and it comes with plastic outer cases and these were difficult to get smooth and friction free, the slightest bend or arc made the movement very stiff and as a matter of fact, I could not even use them and ended up using hollow CF. rod for the outer case which worked very well but slight bends or arcs are out of the question. Just my personal experience, yours may differ.
  ----- Original Message ----- 
  From: Wayne Galligan 
  To: discussion at nsrca.org 
  Sent: Thursday, February 03, 2005 4:49 PM
  Subject: Re: MK Dual Elavator Bellcrank & Pushrod?


  I am in the middle of a major on mine and if it shows any signs of fatigue am going with the pull/pull like Matt described.  I all ready have my servo sideways so why not?  And save a few grams in the process.
  Still the slickest way and most worry free is the .070 dual c.f. rods.   And that will be the way I set up any new plane in the future.

  WG

    ----- Original Message ----- 
    From: Dean Pappas 
    To: discussion at nsrca.org 
    Sent: Thursday, February 03, 2005 3:25 PM
    Subject: RE: MK Dual Elavator Bellcrank & Pushrod?


    That makes you want to run cables in full length guide tubes.

    Dean Pappas 
    Sr. Design Engineer 
    Kodeos Communications 
    111 Corporate Blvd. 
    South Plainfield, N.J. 07080 
    (908) 222-7817 phone 
    (908) 222-2392 fax 
    d.pappas at kodeos.com 

      -----Original Message-----
      From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of Wayne Galligan
      Sent: Thursday, February 03, 2005 4:24 PM
      To: discussion at nsrca.org
      Subject: Re: MK Dual Elavator Bellcrank & Pushrod?


      I took a (2) pieces of foam about 2"sq x 4" long and pushed them onto the c.f rod and placed them about 6 inches from each end.   I could then move the pieces back and forth to tune out the harmonic resonants.  Just watch the rod at various engine speeds to see what it does.  When it vibrates it is amazing that any of them would hold together. 

      Wayne G.
         ----- Original Message ----- 
        From: Rick Wallace 
        To: discussion at nsrca.org 
        Sent: Thursday, February 03, 2005 11:43 AM
        Subject: Re: MK Dual Elavator Bellcrank & Pushrod?


        Agree w/ John about using foam as a vibration damper. Also, someone much wiser than me pointed out that whatever is installed should NOT be halfway, 1/4 way, or any reasonable fraction of the pushrod length because these may end up as stationary nodes in the vibrating rod, and end up doing no good. 

        Rick



        >From: "John Ferrell" <johnferrell at earthlink.net> 
        >Reply-To: discussion at nsrca.org 
        >To: <discussion at nsrca.org> 
        >Subject: Re: MK Dual Elavator Bellcrank & Pushrod? 
        >Date: Thu, 3 Feb 2005 09:07:36 -0500 
        > 
        >Be very careful about alignment. An extra bushing on the shaft can cause a lock up under vibration. 
        >A foam rubber damper is safer. It can be as simple as a wad of foam or as complicated as another bulkhead. 
        > 
        >John Ferrell 
        >http://DixieNC.US 
        > 
        >   ----- Original Message ----- 
        >   From: Jerry Wilson 
        >   To: discussion at nsrca.org 
        >   Sent: Wednesday, February 02, 2005 10:59 PM 
        >   Subject: MK Dual Elavator Bellcrank & Pushrod? 
        > 
        > 
        >   I've mounted the bellcrank and will use Central's carbon fiber push rod.  The pushrod length from servo to crank is about 28". 
        > 
        > 
        > 
        >   Is it necessary to install a support of the rod  halfway down the fuselage to prevent flexing.  And if so does anyone have a simple way of doing this inside a fiberglass fuselage? 
        > 
        > 
        > 
        >   TIA 
        > 
        >   Jerry 
        > 
        > 
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