biggest prop
10-12-2008 | 08:48 AM
#3
Senior Member
RE: biggest prop
Why do you ask?
I've tested a 12x6x3 on a 46AX. Did ok, marginally. Cut it down to 11" diameter and it did better. I wanted to run a scale looking 3 blade and wasn't looking for anything beyond "decent flight". If there had been any 5" or less pitch 3blade Master Airscrew manufactured, I would have cut and tried until it had flown decently. Then would have decided if what remained looked scale enough. But such is not manufactured.
Our glow engines have very usable power over a their decently wide power curve. I fly a 14x7x3 on my OS91FXs and they fly excellently. And the suggested 3 blades for a 90s are 11" and 12". So don't let today's expert advice slow you down. Test beyond what "everybody knows" and you'll find out that everybody doesn't. I worked out the props for the 91s to find a better scale look for my H9 warbirds. One day I had my Sukhoi flying good and hard, and remembered how well the warbirds stunted with their "too large" props. When one of the too large suckers was bolted on that Sukhoi, it freakin came alive. OK, it did better than it'd done with a 2blade that was being flown because it'd won out against a handfull of other 2bladers.
It's amazing what we discover in this hobby when we go beyond what everybody knows.
I've tested a 12x6x3 on a 46AX. Did ok, marginally. Cut it down to 11" diameter and it did better. I wanted to run a scale looking 3 blade and wasn't looking for anything beyond "decent flight". If there had been any 5" or less pitch 3blade Master Airscrew manufactured, I would have cut and tried until it had flown decently. Then would have decided if what remained looked scale enough. But such is not manufactured.
Our glow engines have very usable power over a their decently wide power curve. I fly a 14x7x3 on my OS91FXs and they fly excellently. And the suggested 3 blades for a 90s are 11" and 12". So don't let today's expert advice slow you down. Test beyond what "everybody knows" and you'll find out that everybody doesn't. I worked out the props for the 91s to find a better scale look for my H9 warbirds. One day I had my Sukhoi flying good and hard, and remembered how well the warbirds stunted with their "too large" props. When one of the too large suckers was bolted on that Sukhoi, it freakin came alive. OK, it did better than it'd done with a 2blade that was being flown because it'd won out against a handfull of other 2bladers.
It's amazing what we discover in this hobby when we go beyond what everybody knows.
10-12-2008 | 09:20 AM
#5
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From: Lawrenceburg,
IN
RE: biggest prop
I tried a 12x6 on my new 46AX and it was doggy, now runnng a 12x4 with a 12x5 on order to try next. The 12x4 is nice for the type of flying I like to do, but if you want speed go to a shorter prop (more rpms). Let us know what you find in your testing.
DG
DG
10-12-2008 | 12:38 PM
#6
My Feedback: (13)
RE: biggest prop
for my OS 46AX I use a 11/5 -11/6 seems to be a good match for the engine a 12/4 would be a good match for a plane that needs alot of pull and not much speed like a 3D airframe.
prop size has alot to do with aircraft type, as well as engine size,getting a good match sometimes takes a little trial and error.
prop size has alot to do with aircraft type, as well as engine size,getting a good match sometimes takes a little trial and error.
