With respect to brush wear; before installing my IVO, I put the slip rings in a lathe and polished the contact surface with the hopes that a smoother surface would have lower brush wear.  I have 10+ hours run time in the range of 1500 to 2000 RPM, wear is 0.030" from the original length of 0.340".

Joe

---- Original message ----
>Date: Sun, 18 Oct 2009 09:23:49 EDT
>From: DLOMHEIM@aol.com  
>Subject: [FlyRotary] IVO Prop Question for Chris  
>To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>
>   >I have the IVO Magnum in flight adjustable 3
>   blade prop with 45 to 105 inch pitch range.
>    
>   Chris:  Are you using an ammeter to set you pitch by
>   chance?  If so how much of load is on it at fine vs.
>   coarse pitch settings?  Also have you had to change
>   out your brushes yet?  I am hearing we should expect
>   to get about 15 hrs. on them before needing to
>   change them out and wondered if your ground testing
>   had validated that number yet...
>    
>   Thanks for the information.
>    
>   Doug Lomheim
>   RV-9A, 13B, FWF, IVO
>    
>