multi blade airplane props

[Rappy1]

off the topic of helis, what is the difference between using a 3 blade airplane prop to just the normal 2 blade. I have a p-51 mustang that came with a spinner for the 2 blade but would rather a 3 blade or 4 blade to make it scalewise more real. How do they effect the engine rpm?

[vapochilled]

more blades needs more power to turn
However, more blades means more thrust, but there is a sweet spot.
For instance if a .40 glow engine will spin a 10x8 two blade nicely it will likely do an 8x6 three blade(guessing here) I don't know if there is a formula but most prop makers will recomend an engine size for a prop they make

[Rappy1]

more blades needs more power to turn
However, more blades means more thrust, but there is a sweet spot.
For instance if a .40 glow engine will spin a 10x8 two blade nicely it will likely do an 8x6 three blade(guessing here) I don't know if there is a formula but most prop makers will recomend an engine size for a prop they make

Cheers for your info vapo. i am more than likley going to use the .52 os 4 stroke, would you recomend a prop for this engine hopefully in a four blade. I think being a four stroke it should have a bit more torque for turning a multi blade

[vapochilled]

smallest 4 blade I've seen is a 10x4, and I think the little OS 52 will overheat trying to spin that, anything smaller will jst be worthless.
You need to gear down when spinning multi blade props, adds a lot of weight and headaches,lol
I know it looks good having a multi prop, but you'll be doing yourself a favour if you stick with 2 blades ;)

[vapochilled]

found this:
http://www.zingerpropeller.com/_2_blade_.htm

not sure what 2 blade the 52 spins, but you could get one and try, their not cheap though!

[Rappy1]

thanks again vapo maybe it is best just to stick with the 2 blade. I may just overpower it instead with a os55 2 stroke. the kit says to use a .40-.46 2c or 52-63 4c the 55 2 stroke should give it a bit of power. they also seem to be going cheap as well.

[heli-cuzz]

I have a 1/4 scale ultra stick {78" wingspan} with a two blade 16x8 prop attached to 25.5cc 2-stroke zenoah gas engine. It hovers with no problems and pulls straight out and climbs vertical with ease. :cool:

[Rappy1]

. It hovers with no problems and pulls straight out and climbs vertical with ease. :cool:

Man you can't even leave hovering alone when you aint even flying a helicopter, one would think you are a addicted to heli flight.
I pulled my os 70 4stroke out of my cub and in the process of sticking it in the mustang, man it will pull with that in it. the recomended size 4 stroke for the plane was a 52 -56 heres hoping it will fly.

[heli-cuzz]

Man you can't even leave hovering alone when you aint even flying a helicopter, one would think you are a addicted to heli flight.




All the members at my club field yell, 'hey brian, it's a plane not a heli!'

Addicted to heli-flite.... Yes I am. :D

lol

[Rappy1]

Don't worry heli cuzz there are people out there that can help you fight it. you don't have to tackle it alone.