Prop Difference
 

What changes should i expect when changing from a 3-blade 12x4 propeller that comes with an Alpha 60 to a Master Airscrew S-2 Series 12x5 propeller on the Alpha 60? Things like Top Speed or acceleration changes? I want to replace the 3-Blade, because I bought 3 2-Blade props expecting to need to use them, but I never have. However, I wan to give them a try.

Thanks

RE: Prop Difference
 

Your performance should be the same.

When going from a 2 blade prop to a 3 blade prop, either drop 1" in diameter OR 1" in pitch. When going from a 3 blade to a 2 blade either add 1" in diameter OR 1" in pitch.

Multi blade props are not efficient and most people would not suggest them unless you need ground clearance.

FWIW - MOST people run a 12x6 or 12x7 APC on a 61 engine. The additional pitch will prevent you from over revving the engine while providing a little more power.

I suggest checking your rpms with both the 12x5 and a 12x6 or 12x7 before flying the bird. Remember, the engine is going to "unload" in flight so you will pick up a couple of hundred rpms.

RE: Prop Difference
 

Read the second post of this thread (and the other replies by opjose):
http://www.rcuniverse.com/forum/fb.asp?m=7361348

I think you're refering to the special trainer prop that has blades that look like paddles.

Among other differences the plane should glide more freely with a normal prop. This will of course change how landing approaches work out with your alpha 60.

Normally that would be true, but I think the prop he's refering to is the H9 PTS prop. Have a look at one. They are totally different from other props.

RE: Prop Difference
 

You will see much improved acceleration and top speed. However, as said before, you will also notice it not slowing down as nicely for a landing. you will have to pay more attention to your airspeed on final aproach. Be ready to chop the throttle earlier, and then feather the throttle as you bring it in.
I remember when I took the trainer prop off of my alpha 40, and it took off so fast I almost lost it. The acceleration difference was astounding.

RE: Prop Difference
 

Ok, thanks. I think i will be ok with the acceleration and top speed changes, since i will now be expecting them and prepared for them. I actually think this is good, since i starting to max out the capability of my trainer, so a little extra speed and acceleration should help with some of my manuevers

RE: Prop Difference
 

Hi... I'm flying a Alpha 60 right now with a OS 61 and a 12X7 prop. I tried other sizes but this prop does the best all around job for me. I think it will work for you. GOOD LUCK.[sm=shades_smile.gif]