I think they're a gimmick. From the Wikipedia...
"A gimmick is a unique or quirky special feature that makes something "stand out" from its contemporaries. Product gimmicks are sometimes considered mere novelties, and not really that relevant to the product's functioning, even earning negative connotations. However, some seemingly trivial gimmicks of the past have evolved into useful, permanent features."
Think about propellers, specifically model propellers, our uses, our needs, etc. Think of all the varieties that have been available over the years. Which ones really worked well and which don't? It seems to me that the old Top Flite wood props, and Rev-Up's have a very strong following. If you watch what they go for on Ebay it reinforces that people are paying well more for these older discontinued props then list prices on currently available propellers.
The APC prop came out with this ad campaign talking about how they're more efficient, computer designed, durable, etc. But the question I ask is do we really need these features? Does an APC work better than a 30+ year old Top Flite? In my own personal experience the APC is just about the worst prop for stunt.
I don't like them because they're heavy. Think about this a bit. A typical APC prop weighs MUCH more than a similar size wood propeller. That's more weight the engine has to turn, more drag. The automotive industry would refer to it as reciprocating mass. To see how important its viewed in that application look at light weight wheels, aluminum brake parts, aluminum driveshafts, light weight crankshafts, etc. Further, its weight on the crankshaft, which is going to translate into more heat, more friction, etc. Also if the prop isn't balanced the effects will be more pronounced because of its excessive weight. Obviously this is more important with a plain bearing engine then ball bearing, but still a concern.
Beyond the weight, there are reports of offset mounting holes. If the APC propeller is so much more advanced, and computer designed, why is the ball dropped on what should be a fairly simple operation of putting a hole at the center?
Lets talk about the durability. Obviously for stunt usage, we're not building or planning for a crash, so how important is durability? I'd say its not. However if an APC prop touches ground in a hard landing or soft crash it might not shear a blade, but look closely and it will usually display stress cracks that appear as white marks inside the blade. They have to be examined closely, sometimes they don't show up unless you gently flex the blade. This makes them dangerous.
So basically I can only see a couple advantages. They're cheap, available, and can be had in a multitude of sizes. Are there better props out there for what we're doing? Obviously. So why are they so popular?
I have used APC props. The only stunt configuration I still use them on is the FP20. Otherwise I only use them on small sport planes (.15 size) and carrier planes. Just about any wood prop seems more tailored to our needs, and of course there are the high dollar carbon fibre props. For cheap goofing off props, the Master Airscrew props work very well at a significant weight savings over the APC.
I'm tempted to also point out the gimmick nature of the current Top Flite Powerpoint, but since I haven't used them much at all, and I have one plane that seems to like the one on it, I'll give it a bit more time before I come to a conclusion. However I will say that I've seen some PowerPoints that should have never made it past quality control.
I'm afraid we get roped into buying these gimmick products because the RC crowd buys into them and they're available.
Topic: APC props, my perspective... (Read 9446 times)