ORIGINAL: bjr_93tz
ORIGINAL: Mike Wiz
..People didn't spin their 11x7 props at 15000 rpm because that was the most efficent method of providing thrust for the plane. They did it because that's where these engines made their best power. That's not true of electric power systems. So, can you do it the old way and spin a little prop like mad with an electric motor? Sure but why?
The bottom line is Mike, that my Curare just doesn't fly right with a 12'' diameter prop. I get about 1.5lbs more thrust with a 12x6 APC as apposed to the 11x10 APC that I run on the IC engine thats in there but the plane flies like a bucket of horse droppings.
I believe there's no argument that bigger diameter props are more efficient at the slowflier speeds that planes fly at today, but most of the short coupled planes of the classic era were just not designed for high torque motors and large diameter props. Don't get me wrong, a fourstroke or electric in my Curare with a large diamater prop will do just as good of a job or better than the current screaming two stroke when it comes to pulling it around a schedule but the plane just won't be as ''nice'' to fly.
The planes of the Curare and Magic era need a small prop and plenty of revs to get the same feel in the air. You just can't put in a V8 and fat tyres on a Volkswagon Beetle and get the same driving experience as the original....
This is the rub for the Classic guys as far as I can tell. These models need to fly well and in trim if electric is to be used. But the electric "crowd" get all into the big props and forget that the aerodynamics of the Classic model don't change. Dean seemed a bit hard-line on the big prop thing based on the efficiency of the electric motor, but you can bet he'd use whatever prop it took to make the model trim out if that was the airframe that was to be used.
My last post was a bit of a bridge to the big prop loving posters, because the newer Classics are longer and have bigger surfaces, but for the smaller, older ships the smaller props seem appropriate. Can't wait until someone gets some experience with this type of set-up. Then I could quit using poison paint!
Chris...