ORIGINAL: spadeng
I was wondering about prop diameter vs pitch, specifically whar is the difference between a 10X7 and a 11X6 I know that the larger the pitch the more thrust and lowers RPM but what advantages does a larger diameter prop have??
Back to props.
When I first started to fly my trainer I installed the O.S. recommended 11X7 on my .46. I know that I was at the upper limit here, but I am incorrigible. My instructor, on the second day, had me install a 10X6, which he provided. Wow. Flight stability made me wonder why they recommended the 11X7 at the hobby store in the first place, and landings were easier as well. I think that the vert. performance idea is not an issue until you solo, I have no idea if you have or not, and save your own plane from a fiery death a few times. Top speed is not necessarily a concern either, except as something to avoid until your second plane. These little two strokes like to be near the top of their recommended RPM range. They run better, last longer and teach you throttle control. I said near, not at the top as a safeguard against weird things that happen when in the air. I have referred to my instructor and his prop. theories when newbies ask me about what prop they should run, and when someone has problems with the way their plane handles. People usually want to go too fast and slowing the plane down really helps. Of course I promptly took the .46 out and installed a .75 when I needed an engine for my 40 sized pattern trainer. The 75 breaks all the rules for trainers.[sm=spinnyeyes.gif]