REFLECTOR: engine size & CS prop

[Robin Ream]

Hi Greg,

    My question is perhaps the same as Kurt's; are you running the standard or "hi-pitch" version of the magnum?

Robin
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  ----- Original Message ----- 
  From: Michael Watson 
  To: Velocity Aircraft Owners and Builders list 
  Sent: Wednesday, February 06, 2008 12:20 PM
  Subject: Re: REFLECTOR: engine size & CS prop


  I have been using the IVO Magnum electric CS prop for ten years now.
  Static rpm is 2550, takeoff 27/2750 cruise 8500 is 23.5/ 2590.
  Ivo replaced the drive motor after six years for free, no questions asked.
  He also repaired the pivot arm on one blade and rebalanced the blades
  for free.

  The only problem with the Magnum seems to be not enough base pitch.
  With the Franklin fire walled in cruise at 8500 feet, it tops out at 178 KIAS.
  It also tends to loose the SS prop guard after six to eight hours, which 
  sets up a slight vibration making the flight back to base interesting .



  On Feb 5, 2008 6:16 PM, Greg Poole <greg at pooledresources.com.au> wrote:

    Care to let us know what cruise/top end you are seeing with that combo Tec?  "Aus"sume you are STD RG elite from memory…



    Greg 

     greg at pooledresources.com.au 





    From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of HYTEC45 at aol.com
    Sent: Wednesday, 6 February 2008 01:32
    To: reflector at tvbf.org
    Subject: Re: REFLECTOR: engine size & CS prop



    In a message dated 2/4/2008 4:26:44 P.M. Pacific Standard Time, stedmanlou at adelphia.net writes:

      My problem is that I am not too happy with the RPM I get on takeoff. The best I see is about 2300.

    I do not have the length and pitch of my catto at hand, however, I ran for almost 500 hrs with a performance 3 blade (then switched to an mt, then pitch the POS mt then went with the Catto).  While the Performance worked good all around, giving me 2450 rpm on take-off, the Catto will give me 2335 rpm static, then once at approximately 40kts. the prop loads up and rpm drops to 2280.  I do not see 2400 rpm until 110kts.  This being said, the Catto, even though lugging the rpms down more than the Performance, it gives me approximately 15% reduction in take-off distance and the acceleration is noticeable from the seat.  Catto has the blade design down and more of the inner portion of the blade is biting in at lower speed.  I think the Performance is cavitating in more of the root area than the Catto until airspeed picks up on take-off.  Once at 120kts and above, both props perform the same.  I have a IO360 with 10-1 pistons and came ground to optomize them.  I am putting out approximatly 220hp. which I related to Catto when I ordered the prop.  I'm sure I have more pitch than you, however the rpms sound right.

    TEC  






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  -- 
  Mike W.
  1997 Velocity Elite RG
  Franklin /IVO Electric CS 


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