Beginner Pilot FT Flyer Prop Question

[Alzey]

Scratch building an FT Flyer and have a question about props.

My setup:
24Gram 1300Kv motor
Turnigy Plus 18amp ESC
800 2C battery
Turnigy 9X radio/reciever

I have a choice of 2 props for this setup on hand. 8x4 prop and 9x4.7 Slow Fly prop.

My question is what will each of these props do in this setup? I am a total noob at this and still learning. My only source of advice for now in this forum and FT videos.

Thanks,
Alzey

 

[brettp2004]

Both will probably work fine. I'd start with he 9x4.7 and see how it goes. Someone wth a little more knowledge might chime in, but your motor/ESC combo will handle both props with no problem. Start out on the 9" prop since it will give you a little more power to get you out of trouble. Once you get proficient at that, try the 8". There probably won't be a huge difference between the two, but the 8" will give you longer flight times.

 

[Snarls]

LooseBruce, you're right about the 9X4.7 technically overpropping the Blue Wonder by Hobbyking's specs. Even so I have always run a 9X4.7 on mine and have never had any problems. With the FT Flyer I can cruise around mid throttle all day and the motor is cool. I also tend to punch it closer to full throttle for a few seconds at a time for vertical climbs and still have no trouble. I do wonder if what brettp2004 says is true and that the 8" will give more flight time, but I prefer 9" for slow flying with lots of power.

One other thing to consider is that the 8" props form HK I got are brittle and break when they hit things. The 9" SF props tend to just chip a little or bend but are still in flyable condition. Not sure if you have the same type of props Alzey, but the 9" props are more forgiving if you are prone to crashing or hitting stuff.

 

[earthsciteach]

Some folks have posted prop/amp/thrust data in the "discussion" area for this motor. The 9047 is pushing the motor rating, but not by much. Of course, take everything with a grain of salt.

Overall Rating Paul Bakos likes Value UNRATED Quality UNRATED 49 thumbs up!

Propeller data for 3 cell Lipo batteries: The GWS EP 9050 produces about 18 ounces of thrust at 9 amps with a pitch speed of 34 mph. This is my favorite prop on this motor. The APC 9x6E produces about 17 ounces of thrust at 10 amps with a pitch speed of 36 mph. The APC 9x3.8SF produces about 18 ounces of thrust at 9.5 amps with a pitch speed of 25 mph. The APC 8x3.8SF produces about 15 ounces of thrust at 8 amps with a pitch speed of 29 mph. The GWS EP 8040 produces about 15 ounces of thrust at 6 amps with a pitch speed of 34 mph. The GWS EP 8060 produces about 14 ounces of thrust at 8.5 amps with a pitch speed of 39 mph. The MA 7x4 3-blade produces about 10 ounces of thrust at 7.5 amps with a pitch speed of 36 mph. Propeller data for 2 cell Lipo batteries: The GWS EP1060 produces about 12 ounces of thrust at 6.5 amps with a pitch speed of 28 mph. The APC 9x6E produces about 11 ounces of thrust at 6 amps with a pitch speed of 29 mph. The APC 10x3.8SF produces about 12 ounces of thrust at 6.5 amps with a pitch speed of 17 mph. No comments. Reply..

Overall Rating Donald Bond likes Value UNRATED Quality UNRATED 24 thumbs up!

Great bargain, high efficiency, great for little foamies! 8x4, 7v, 3a, 6350rpm, 6.6oz, 24mph 8x4, 10v, 5.1a, 8205rpm, 11.2oz, 31mph 9x5, 7v, 4.7a, 5361rpm, 8.9oz, 26mph 9x5, 10v, 7.2a, 6905rpm, 15oz, 33mph 10x6, 7v, 5.7a, 4675rpm, 9.4oz, 27mph No comments. Reply..

Overall Rating Dave Plumpe likes Value UNRATED Quality UNRATED 19 thumbs up!

I measured resistance, no-load current and Kv to get data to plug into Motocalc. Resistance, R = 0.319 ohms No-load Current, Io = 0.22 amps at 6 volts, 0.30A at 9V Motor Constant, Kv = 1079 rpm/volt These data differ a bit from the 1300Kv and 0.5A listed in the ad, but this is what my motor measures, cold. One excellent little motor, both in performance and build quality. As others have noted be careful about bending the wires where they exit the windings. Mine came as shown, without connectors or hardware. 2 comments. Reply..

Overall Rating David Barrow likes Value UNRATED Quality UNRATED 16 thumbs up!

These are great little motors for the price. I bought one and then got two more. I use them on home made foamie planes from 8 - 16 ounces. They will take most of my foamies unlimited verticle. I use 2 and 3 cell lipos from 350-1500 mah and props from 8x4 to 10x4.7 on them. Here is some data. UH BLUE Wonder 1300Kv Prop size= amps / thrust in ounces 2S 8040= 3.3 / 8.2 9050= 4.9 / 10.8 9047= 5.3 / 10.9 1047= 6.5 / 11.5 3s 7035= 4.2 / 9.5 8040= 5 / 13 7060= 6.3 / 11.3 9050= 6.6 / 14.6 9047= 7.6 / 15

 

[PhenomPilot]

I would go with the 9x4.7 prop on a 2s (two cell) lipo. A smaller prop will give a longer flight to certain point until it becomes inefficient. The 9x4.7 shouldn't be stressing that motor much on 2s. On 3s, the 8x4 prop would probably be the better choice.

 

[Alzey]

Well, the FT Flyer is what I needed for some successful flying in my back yard. At one point had it in the air for little over 5 min making several laps of my yard. weather front was moving in so I had a good head wind and was hovering in a high alpha. One one lap a gust hit me broad side and flipped me into the ground. One more broken 8x4 prop. Finally had to call it quits from the wind and headed in. Battery was at 52%. I call this a great success. On vacation next week and hope to get a lot of flying in and get more comfortable.

Thanks for the great info and advice on this site.