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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Larry Wong on October 04, 2009, 05:13:17 PM

Title: Pusher 13x4.5 EP
Post by: Larry Wong on October 04, 2009, 05:13:17 PM
Today I tryed the new 13x4.5 pusher props ,  I cut one to 12" and the other I left at 13" both flight were to slow the RPM has to be set higher, went back to my 12x6 EP and all is well. will have to try more RPM but I think  slower RPM and higher pitch would be better, any way need more testing.
Title: Re: Pusher 13x4.5 EP
Post by: Archie Adamisin on October 04, 2009, 07:12:15 PM
Larry,

What RPM are you set at and what length lines?  What is your desired lap time?  10,300 RPM seemed to be the starting point for this prop.  That acheived a 5.4 lap time on the Strega @ 79 ozs and 66' eye to eye 0.018" lines.  This also worked for the Pathfinder with the prop cut down to 12" using the same lines. 

The purpose of this prop was to get the rpm's up to get the motor in more of a sweet spot (70-93% throttle on the Phoenix) and to increase the resolution of the governor by making any change in RPM have less effect.  I think that once you have your RPM set, you will like the lower pitch better.  If you try the ful 13" versus the 12" on the same airframe, you will have to be higher on the rpm for the 12" than the 13" by nature of the increase in thrust with the larger diameter.

Archie Adamisin
Muncie, Indiana 
Title: Re: Pusher 13x4.5 EP
Post by: Dennis Adamisin on October 04, 2009, 08:14:36 PM
Hi Larry
I recommended 10.300 as a starting point, Crist Rigotti reported success at 10,600 RPM  Your milage may vary!

I think you will REALLY see the improvement for lower pitch on a windy day....
Title: Re: Pusher 13x4.5 EP
Post by: Crist Rigotti on October 04, 2009, 09:11:00 PM
I think my lst flight was at 10,400 in St. Louis.  Yup a good prop.