3 blade prop for 50cc

[propchief]

Thinking of going to a 3 blade prop for a 50cc Extra 300 ... maybe the PT 21x10 or the Mezlik 21x11.5N. ANyone have any experience or recommendations on this?

Thanks
John

[ckeene9]

Just picked up a 21 x 10n, let you know how it works after I try this weekend next to a 22 x 10 2-blade.


C

[Anscrew]

Advice : wouldnt bother. best bet is stick with either 22 x 10 or 23 x 8

[mbacosa]

My question is why. Performance wise the two blade is a better option. The 3 blades look cool but on a 50 cc you would suffer on the power IMHO.

[Mr. Nobody]

I know this is an old thread, but anyway, I'm running Mejzlik 20 x 10's on both of my 50cc planes. Reason why is because I need the tip clearance (to the ground) because both of these planes are a tad small for 50cc engines and 22" props. Also, I think they look cool. They fly perfectly, but again, I'm doing mostly IMAC, not really 3D. Finally, these planes are overpowered anyway, so if I'm loosing anything it doesn't matter to me--I can't say I'm "suffering" any loss of power or performance any way that I can detect.

[Borries]

	Quote: Originally Posted by propchief
	Thinking of going to a 3 blade prop for a 50cc Extra 300 ... maybe the PT 21x10 or the Mezlik 21x11.5N. ANyone have any experience or recommendations on this? Thanks John

Have a Mezlik 21x11.5N 3 blade on a DL50 still on mineral oil (no run in yet) 6600 RPM no problems !

BB

[robertp17]

I have thought about doing this as well for braking and sound improvement but IMHO most of the newer, bigger 50cc airframes out dont have enough power for Imac as it is with a 50cc. I can 3d the crap out of my 50cc all day long and feel that it has plenty of power but if I want to pull a long upline with a 1/2 roll on it, it gets mushy at the top and stuggles to keep climbing. That is why I wont use a 3 blade on my 50cc. However if I had a 78" to 82" inch light airframe then I may be able to run the 3 blade as it would be overpowered. If you think about it, that is why the 35 and 40%ers are so much better for imac. On a 35%er you double the engine size, yet only have a 5% bigger airframe. My 2.6 comp has 3 blade on it and it pulls just fine, however it pulls harder with a 2 blade.

[SLRDave]

Robert is correct that you can double the engine displacement when going from a 50cc to 100cc, but you don't double the thrust potential. Also, the 5% increase in scale of the airframe translates into an almost 70% increase in weight for most models. If you don't need the torque for 3D and want to decrease your noise footprint, a 3 blade prop may be the way to go. And if you have a plane like mine that squats on hard landings, the extra ground clearance of a 3 blade may pay for itself in saved prop damage.