I think I should expand a bit on what I'm doing with the prop change. Since I haven't seen much data on the Evolution .61 engine and how it performs with various props, I’ve decided to experiment with different brands, sizes (pitch & diameter) and materials of props with and with-out the flywheel. I'm not after speed as I have several planes that are capable of flying over 100 mph and the Alpha 60 would probably come apart at the seams flying at that speed.

I want to find out which prop will offer the best overall performance - speed, climb, basic aerobatics, and general overall flying and training characteristic. Changing from the 3-blade 13 X 4 prop to a 2-blade 12 X 6 should allow me to fly at a lower RPM for the same speed and hopefully reduce the sound level a bit. It should provide a better glide with the big air-brake off the nose - I've flown an Alpha 40 with a 2-blade and it will by far out-glide my Alpha 60 with the 3-blade. My initial trials will be with 12 X 6 Top Flight wood, Evolution 2-blade and APC (I'll have to modify the spinner for the APC to fit). From there I'll move around in pitch, diameter and material type just taking my time evaluating how the plane responds. I’ll be using a tach to record the RPM on the ground (top end and idle), then flight test each prop at least 2 or 3 times using the same flying routine. I’ll repeat this process using the flywheel hub that comes with the plane and a plain hub with-out the flywheel. The only variable should be the weather and this unfortunately can’t be controlled.

This is where RC can be fun - playing around with different combos to see what response or characteristics are evoked from the plane – and what I find I like may not be what the next guy out there likes, but that’s what makes this hobby so great! And this is another example why you want to keep a trainer flying after you’ve moved on to bigger, better, faster planes.

Hogflyer