[C320-list] Prop shakes

[Peter Clancy]

I installed a Gori 2-blade folder three years ago on 'AROBAN' and never experienced vibration problems.

 I understand that Gori props are precisely balanced when manufactured so it's unlikely the prop itself is the problem. A loose cutlass bearing or a warped shaft could be the culprit. However, incorrect installation of the prop is also a common cause. For example, it's critical to 'mate' the propellor to the shaft by eliminating any out- of- roundness between the two mating surfaces. This is done with valve grinding compound and by spinning the prop on the shaft until it turns smoothly. The other step is to assure the prop is set fully back on the shaft. It's possible for the key to jam in the keyway as the prop is pushed on to the shaft thus preventing it from seating firmly. 

Peter Clancy
'AROBAN'  C320  #222 (former owner)
Miami, FL



  ----- Original Message -----  
  From: Pat Moriarty<mailto:patm at psiurethanes.com> 
  To: C320-List<mailto:c320-list at catalina320.com> 
  Sent: Thursday, October 18, 2007 10:15 AM
  Subject: Re: [C320-list] Prop shakes


  Machine what? Mine did it brand new but gets worse at RPM and I had a 
  new cutlass bearing .

  Pt #130

  At 08:55 AM 10/18/2007, you wrote:
  >My Gori two-blade has started shaking and rattling at intermediate
  >engine-speeds.  It smooths out fine once I rev up.
  >
  >My mechanic says he sees this a lot and it "needs machining".
  >
  >Anybody had a similar situation?  Did machining fix it?  Any other advice?
  >
  >Dave Moores

  Pat Moriarty
  PSI Urethanes Inc
  PH: 800-888-5156  Fax: 512-837-8733
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