I am running out of propellers so I am going to order some more in a bit. I picked up what the store said was a good propeller size, I can't remeber what they were. Anyways, I want to get some that would allow a slower speed better for a beginner like me. After I get more flying time I would like to speed things up a little.

What prop sizes should I order? The Plane is a hangar-9 Pulse 60 with an evolution .61 engine.

Also can someone explain the what sizes will do what? I know different length and pitch will perform different, I just don't know how.

Thanks.

A larger diameter prop will not allow the engine to rev up as much (top rpm is reduced). The pitch will determine how fast/far you can go.

The pitch is how far the propeller will travel in one revolution - a 6 pitch will THEORETICALLY travel 6" in one revolution. In the real world it is a little less.

As for prop size, I suggest starting with what is recommended in the owner's manual and then adjust the diameter/pitch based on what you want/need the plane to do.

So for slower flight I would want a larger diameter, low pitch prop, and for higher speed I would want a smaller Dia. large pitch prop?

Yep.
Evan.

Within reason. There are limits. You want to remain in the torque and power band of that engine. To high an RPM (low pitch small diameter or both) and you will exceed the RPM range that the engine will give you the best performance. Over prop it.. higher diameter or pitch or both, and you get the opposite.. you get below the optimum power band and you just can't do anything with it.

The only real way to find out what you want is to buy several props, each in the range of the recommended props for that engine, and try them. Find one that will keep your RPM in the optimum range and give you the best performance.

CGr.

A good rule of thumb to follow is to start with the recommended prop from the manufacturer. If you're not satisfied then modify as follows.

If you want more thrust on up lines, shorter take-offs, and more drag at low throttle settings, and are willing to sacrifice top end speed, then get an increased diameter prop. For each inch diameter you increase it, decrease your pitch by 1 or 2. For example, if you're currently running an 11x6, then try a 12x5 or 12x4. This will keep the engine in the same torque band, and top end RPM should be about the same.

If you want to increase speed, but sacrifice upline thrust and have longer takeoff rolls, reduce diameter by 1 inch, and increase pitch by 1 or 2.

Different types of props have different performance characteristics for a given size as well. For example, wood props are very stiff, but tend to be fragile. APC props are stiff and strong. That stiffness allows the prop to retain its shape better at high torque, and will give improved performance. MAS props or nylon props are strong, but not as stiff, and will bend slightly under high loads. They are less likely to break on ground contact, but may sacrifice some performance. Many people like them because they lend a more scale appearance.

Perhaps if you were more specific on your engine, we could give you some specific prop recommendations.

Brad

Why don't you just use your throttle stick to adjust your airspeed. Da simple solution isn't it.

Hi!
That's hard for a newbie!!!
Better to prop right!

A 14x4W APC is good if you want slow flight speeds, another is 14x5N , 13x4 or 13x5.

Simply using throttle is not any kind of solution.

At full idle, if the plane is not going slow enough for your liking, you can't throttle back any more. Plus, having a smaller pitch will help act as an airbreak, just using your throttle won't.

The Horizon web site says the Evolution 61NX "Benchmark Prop" is an APC 12x6 @ 12,000 rpm. In theory you'd have a top speed around 68 mph with '6 pitch' at that rpm.

APC makes a 13x4 and a 13x4W prop. The 'W' means wide blade. The wide blades put more load on the engine and should produce more thrust than the standard blades at a given rpm. Theoretical top speed at 12,000 with a '4 pitch' should be around 45 mph.

I have used a 13x4W on a .61 two stroke and liked it. I've never tried any 14 inch prop on one so I do not know if the engine has enough power to run one.

I currently have a 12x6 on my ASP .61 two stroke and it seems like a pretty good match on my Uproar 60. I have a 13x4, and maybe a 13x4W, in the prop box; maybe I'll try one of them in the spring.

Minn is correct.
When landing you need to keep your RPMs where you won't die
and get your speed down; a lower pitched prop helps with this.
I automatically go for a low pitch prop as I am more interested in
power than speed.
Good Luck,
KW_Counter

I have the H9 Pulse XT 60 with a OS 61 FX and an APC 12x6 prop. It flies great with that combination. Good verticle power with large loops. It also slows down nicely for landing. I have been flying it since fall 2008.

Bruce