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Constant speed propeller
- Thread starter seagull
- Start date
I’m interested! I have looked casually at the options over the last year but haven’t really taken a deep dive yet. RS Flight Systems make a single lever controller for use with MT governer. That’ seems the most interesting to me but I didn’t get far enough to price it all out. It will be costly for sure, and there an argument that we are in a performance where it’s hard to get a payoff…but it would still be fun to do.
You asked about CS, but you’re probably going to get a bunch of people telling you to do something else instead.
In my opinion, the juice isn't worth the squeeze for the RV-12. The only plus would be shorter take-off and climb. Do you really need that in the -12 enough to off set the cost & weight?
Piper J3
Well Known Member
Consider a 3-blade E-Prop. I see 120 knots TAS cruise @ 5500 RPM / 3000 MSL and add’l 200 FPM initial climb rate. When I fly solo w/ half fuel I often see 1200 FPM climb. Prop is butter smooth...
Most airplane fixed pitch props are pitched for Climb, Cruise, or Combination Climb/Cruise. The carbon fiber E-Prop is fixed pitch, but the prop tips flex in flight depending on prop loading. In climb… the prop is loaded heavily and the tips flatten out a little bit and prop behaves like excellent climb prop. When you pitch-over into cruise flight the prop unloads and prop tips revert back to static pitch setting and you then have excellent cruise performance.
Most airplane fixed pitch props are pitched for Climb, Cruise, or Combination Climb/Cruise. The carbon fiber E-Prop is fixed pitch, but the prop tips flex in flight depending on prop loading. In climb… the prop is loaded heavily and the tips flatten out a little bit and prop behaves like excellent climb prop. When you pitch-over into cruise flight the prop unloads and prop tips revert back to static pitch setting and you then have excellent cruise performance.
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flightdoc101
Member
I spoke with Dick Van G himself who did convert one of his 12's, (has and iS and a ULS) to constant speed prop. His assessment was not worth the effort. No increase in cruise. Something to do with frontal area.
Ok, that seems weird because I have made a number of pitch changes just for the fun of it, and without a doubt there is a shift of the performance between climb and cruise. The recommended pitch does seems to well optimized, but pitch changes make a difference and higher cruise speeds are there to be had. Must be some nuance missing, the man would know.
I feel there is a sweet spot where the prop (Sensenich 2 blade) is best at both. I have tweaked mine .1 degrees, a lot until I hit it. My currently numbers at 3000’, gross wt, I get 1000 ft/min and 119 kts level at 2400 rpm.
