whoareyou310

I am putting my oS .46 FX in a phoenix 300 ARF I bought, and would like to know the most ideal prop for my engine. The manual says there are a few different sizes I could use and I haven't been in the hobby for a few years and I am having a hard time remembering what I should do. Thanks for the advice.

fredscz

My Feedback: (47)

I like the APC or MAS Simitar 11x5 or 11x6. Plenty of pull along with good speed.
FEB

masonman

11X5 APC......

bigdanusa

Word of caution: Don't let the phoenix extra 300 get too slow on you because it has a tendency to tip stall and you may be out 1 plane, unless you are up high enough to recover.

It also has a tendency to bounce on landing if you don't grease it in, but no harm done.

That plane is not a floater and it likes speed. Therefore I would recommend using a 10-6 apc prop for your O.S. 46 engine.

I have that plane in my gallery with an O.S. 55 AX w/pitts muffler running a 11-7 wood prop. Some have claimed that a .46 just doesn't get it for that plane, but will still do the job.

It's fun to fly, rolls pretty fast, goes where you point it staying right on track, but feels like you are flying a "little brick" around.

I still love mine after 150 plus flights on it.

big dan

apwachholz

This is a completely shameless plug of my own web site but, even I reference the prop chart from time to time when I'm dealing with my rc airplane engines. Actually, that's a big reason why I created the site, I need to remind myself of all these things all-2-often (Note: The information is from many propmanufacturesmanuals and acompilationof many different locations information.)

http://www.controlchat.com/props-and-propellers/

jetmech05

I second the use of APC props....but they are sharp and I have the scars to prove it......I'd probably do an 11x6, or 11X7....

malthepal

My Feedback: (1)

I am flying the phoenix models giles with the .46 in it with a pitts muffler. I fly with an apc 11x6 and it seems perfect. Plenty of pull, but I bring it in under power. I also agree that APC props can have very sharp trailing edges. Use a starter or a chicken stick.

oldtyme

I use a 10 x 6 or an 11 x 7 for the OS46FX I have in my GP Escapade and they work very well.

RCKen

My Feedback: (9)

Unfortunately there is no "ideal prop" for your engine. What Imean by this is that it's next to impossible to state that one given prop is the best for any given engine. This is because how you intend to fly your plane will determine the prop that you will put on your engine/plane. For instance, for 3D flying you want a prop that has a lower pitch that will give you more "pulling power", however if you want your plane set for speed you would go with a higher pitch that will make your plane faster. The diameter of your prop will also vary on what your application will be as well. That manufacturer of the prop is also another factor as different brands perform differently.

The adviceIgive people in a situation like this is to gather the information you get here in this thread and then make a selection on several size props and then simply start trying each prop on your plane until you find the prop that would be best for your style of flying.

Ken

CGRetired

My Feedback: (1)

Ken beat me to it.

I have a small (?) collection of props, more like an obsession with props... well, maybe a drawful... quite a few, anyway.

I will take a generally suggested prop size and fly with it. Then, after playing around with it for a while, I will land and change props and try again. I will repeat this until I have the right prop for that engine and plane combination.

You see, not all planes are equal. They all very in weight and engines vary slightly in performance, depending on how it is broken in and setup afterwards.

So, since you can get several props for about $20.00, and start your own collection.. , you probably should do as both Ken and I suggest and spend a day of flying just swapping around props and flying with them. You will eventually find the right one for your setup.

I'm sure you know this, but here's a bit of an explanation about props. Take a 10-7 as an example. The first number is the prop's diameter in inches or 10 inches in diameter. The next number is the pitch, or the distance the prop would travel, in inches, with one revolution of the prop. So, a 10-7 is 10 inches in diameter and will move 7 inches forward in one revolution.

The higher the pitch, the further it will move through the air. This is, of course, in perfect conditions. And, like a transmission in a car, the lower the pitch is, is the same thing as shifting down in gears in a car. You get more power, but the engine RPM are higher for the same speed, and the top speed is lower, and conversely, increasing the pitch will increase the top speed at the expense of pulling power.. it will take longer to get there.

With that in mind, I would suggest you pick up several props in the range that you would intend to use, and give them a try. As I said, you will find one that does what you want and will probably stick with it.

Just remember a few things about engines and props. Noise does not equate to power. If it makes more noise, well that may not be desirable. In a lot of clubs, noise is a broken sacrament..

Good luck.

CGr.

CGRetired

My Feedback: (1)

Here is a simple chart that shows, in a perfect world, the pitch and the miles per hour expected at the given RPM.
Note that this is in a perfect world in statute miles per hour, that is, not in nautical miles per hour, no slippage - cavitation, no wind, and, most of all, no drag. I stopped at 8 pitch, but can go on and on if you wish. What this means is that the second number in the prop... 10-7 for instance, the 7 is the pitch. This does not indicate thrust, of course, just speed. And one more consideration is that if the engine in use is capable of turning the prop at the given pitch.. this is what you would get in speed:

Prop Pitch @ RPM Miles per Hour
4 Pitch, 5000 RPM 18.94
4 Pitch, 6000 RPM 22.73
4 Pitch, 7000 RPM 26.52
4 Pitch, 8000 RPM 30.30
4 Pitch, 9000 RPM 34.09
4 Pitch, 10,000 RPM 37.88
4 Pitch, 11,000 RPM 41.67
4 Pitch, 12,000 RPM 45.45

5 Pitch, 5000 RPM 23.67
5 Pitch, 6000 RPM 28.41
5 Pitch, 7000 RPM 33.14
5 Pitch, 8000 RPM 37.88
5 Pitch, 9000 RPM 42.61
5 Pitch, 10,000 RPM 47.35
5 Pitch, 11,000 RPM 52.08
5 Pitch, 12,000 RPM 56.82

6 Pitch, 5000 RPM 28.41
6 Pitch, 6000 RPM 34.09
6 Pitch, 7000 RPM 39.77
6 Pitch, 8000 RPM 45.45
6 Pitch, 9000 RPM 51.14
6 Pitch, 10,000 RPM 56.82
6 Pitch, 11,000 RPM 62.50
6 Pitch, 12,000 RPM 68.18

7 Pitch, 5000 RPM 33.14
7 Pitch, 6000 RPM 39.77
7 Pitch, 7000 RPM 46.40
7 Pitch, 8000 RPM 53.03
7 Pitch, 9000 RPM 59.66
7 Pitch, 10,000 RPM 66.29
7 Pitch, 11,000 RPM 72.92
7 Pitch, 12,000 RPM 79.55

8 Pitch, 5000 RPM 37.88
8 Pitch, 6000 RPM 45.45
8 Pitch, 7000 RPM 53.03
8 Pitch, 8000 RPM 60.61
8 Pitch, 9000 RPM 68.18
8 Pitch, 10,000 RPM 75.76
8 Pitch, 11,000 RPM 83.33
8 Pitch, 12,000 RPM 90.91

RCKen

My Feedback: (9)

To add to CG's "perfect world" here is a good tool for doing comparisons in props. Thrust HP will help you make comparisons and help you narrow down the list of props that you can work with in real world testing at the field

http://www.hoppenbrouwer-home.nl/ika...rusthpv20d.htm

Ken

speedracerntrixie

My Feedback: (29)

Check your CG. What you are describing is a nose heavy airplane or one that is just plain heavy.


For the original poster, I would put in a second reccomendation for an APC 11X5

jaka

Hi!
The best prop is either an APC , RAM or Graupner Cam-prop 11x6, 11,5x6 (APC), 12x4.

MetallicaJunkie

11x6 apc is great overall prop for this motor or 10x8 apc if you want more speed.... or 12.25x3.75 apc for 3d

TimBle

I would steer well clear of an 11x5. Its just lacks the pull even if the engine gets a little higher rpm.

I have the Black Horse Extra 300 which is similar to the Phoenix. I had a GMS 47II is there and I ran the 11x6 which was excellent but a 11x7 was perfect.

I have run a 12x6 on the same engine is a Sportsman Aviation FW 190 .40 that weighs around 200gr more than the Extra with more drag and it turns that prop at over around 10500rpm whihc is perfectly adequate for scale flight.
For the extra you want more punch and I have found the 11x7 JXF works brilliantly.

I have tried an 11x5 APC, MAS and JXF on the BH Extra and they all sucks. The plane goes nowhere. Vertical is pretty poor since they just do not delvier the thrust.

Try 11x6 Wood or APC or MAS
Try 12x5 Wood or APC
Incidentally the 12x5 had more pull than the 11x5 on the .47

bigdanusa

Most all recommended props work for the .46, some just work better than others for your style of flying. For my style I'd use a 10-6 if I am using a .46 on that plane. I'm sure others will disagree....as usual.

big dan

bigdanusa

My phoenix extra 300 "is" balanced in the recommended range and no, it's not too heavy. Buy one and you'll see that plane has a tendency to tip stall at low speeds!

big dan

TimBle

Where the Cg should be positioned also depends on the wing incidence and thrust line.

Do yourself a favour and check your planes wing and stab incidencs rfelative to the thrustline. I suspect you have a problem there that may require moving the CG forward.

My extra does not tip stall unless its barely flying and I only do that If want to intentionally enter a spin.

bigdanusa

As far as the incidences on the phoenix ARF the stab slides into a slot and the wing sits right onto the wing saddle. I was assuming that's where they intended the incidents to be.

Maybe I "will" move the CG around to see if that helps. That is, if my cats haven't torn it to pieces before the new season starts.

big dan