[NSRCA-discussion] Electric props vs. standard pattern

[Ken Velez]

Hi Dave,

 

It seems to me that the electrics are not turning comparable numbers. Most
setups are turning in the low to mid 6000 and only 1 or 2 set ups are in the
7000 and none in the 8000 that I know of. This is based on what I have
observed only; so there could be a setup turning higher numbers; and on a
10S battery. If you go to more cells = more Volts = more RPM's also more
Amps. FAI is caped to 10 cells not sure about AMA. My Hacker A-60 is on the
mid 7000 and we were using the 18.1X10-11-12 glow props; while it flies very
nice with these props the plane is very slow for top classes and or wind. So
right now I'm using an E prop; huge difference. It's also my understanding
that the E props are more efficient than the regular glow props not 100%
sure but pretty certain about it but you are correct about the stiffer is
more efficient when comparing 2 identical props lets say one plastic and one
carbon but not equal when comparing different airfoils. An APC 20X10 E will
be more efficient than a 20 X10 Glow and if you can make the APC 20X10E in
Carbon it will be more efficient than the original 20X10E etc. Just my
observations. 

 

Ken

 

  _____  

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Dave Burton
Sent: Monday, September 07, 2009 11:04 PM
To: 'General pattern discussion'
Subject: Re: [NSRCA-discussion] Electric props vs. standard pattern

 

Why are we using the Electric style APC props on electric powered pattern
planes rather than the standard pattern props? We are turning the electric
motors at comparable RPMs to a glow engine. The standard pattern props are
stiffer and should be more efficient it seems to me. I can understand a
little weight savings if needed but is that the only reason for using the
E-props? What am I missing? Anyone compared similar E and standard props in
the same sizes? What results did you find? 
Dave Burton

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