Wedge9k

I've tried to find some additional information on the web but wasn't very sucess full. All that I understand about them is that they will make the propeller's rpm's slower than the rpm's that the actual moter is putting out. Wouldn't you want more rpms?

Also, if anyone knows, how fast do batteries charge in the feild (the Li-ions 1500mAh)? Also, if i had 3 for one plane (4500 mAh) then would I need 3 chargers or could I could I charge them With only one.

Thanks
Cameron

crewchief_432

you use a gear box so you can swing a larger prop.larger prop =more thrust.from what I have seen direct drive motors with smaller props give you more speed.

budrodis

i us e a 1500mah battery and it usualy takes an hour, you have to charge at 1 times the capacity( i.e. 1500mah charges at 1.5
amps). u cannot really fast charge lithiums.


will

Jim Finn

My Feedback: (2)

Gear boxes allow you to use a larger ,more efficent prop with out hurting the motor. Some gearboxes have changeable gears to change the ratio. This gives one motor more flexability to fit different planes. So you can adjust the Prop size...Cell count ....cell size... and motor to fit your needs. Very flexable but also complex. Motocalc or Electracalc will help you to learn all this. They are computer programs that cost about $40. Motocalc allows you to download it for free for 30 days.

Wedge9k

Thanks for the informaion. I have one more question then. If you increase the Thrust with a bigger prop, then will it be able to fly more weight and climb easier? Or would speed do that?

Jim Finn

My Feedback: (2)

Well yes a bigger prop gives you more thrust but at a cost of shortening the motor run time. Bigger prop also increases the amps a lot! Easy way to kill a motor. Also depends on the amt. of lift the wing can produce. The wing after all does the lifting the prop just moves the acft. forward.

wsudrick

Ok. So whats better-speed or thrust? Wouldnt thrust = speed?
I'm so confuuuuused!!!!!!

Jim Finn

My Feedback: (2)

Think of it this way. Speed is top end as in 3rd gear . Thrust is low end like 1st or 2nd gear in a car or bicycle. To accelerate in a car you use lower gears. Same with props. To go fastest you want high gear. Driving in low all the time limits your top speed, right? Starting out in high gear will mean a slow acceleration.

3D Flyer

My Feedback: (37)

For 3D flying you want a hight thrust, high torque, low speed setup.
3D flying is done at low speeds in a post-stall state. That is why the
3DX, for example, has a large prop (12x6) and is geared down 6.6:1 using a HiMax
2015-4100. They hover and torque roll great but do not fly really fast
as they are menat for 3D flying.

hope this helps