Specifications

6.4.1.20. Quick Sweet 16 EP motors

The main gear is 120T, and the available pinions are 10-14T for 5mm shafts.

• Aveox 36/38/3 (brushless, 20 cells, 12-13T)

6.4.1.21. Summary

If you choose a brushless motor, then an autorotation gear is highly recommended. Most

brushless motors have extremely high torque so when the motor spools down, the "braking" ef-

fect will be very strong. This will very likely break the main gear teeth if you do not have an

autorotation gear. The only exception to this is the Corona; the main gear on it is very tough

and can handle a brushless motor without an autorotation gear.

The older sensored Aveox motors (12xx and 14xx series) are only rated to 20,000 rpm, and

the JETI motors are only rated to 15,000 rpm. You must be careful not to exceed these rota-

tional speeds otherwise the rotor may eject a magnet (i.e. "throw a magnet"). Therefore, I do

not recommend these motors for helicopter use. The better motors such as the newer Aveox,

MEGAs, Hackers are typically rated for 50k-70k rpm, which makes them a better choice for

helicopter applications.

The Model Motors 2814/10 is not recommended for an ECO 8. The motor seems to have prob-

lems with the rotor wobbling and touching the stator windings which burns out both the motor

and the ESC. There are also some reports that the magnets are not epoxied very well to the

rotor and may shift position. Also, these motors are not very efficient, and run very, very hot

when used in a helicopter.

Most of the HiMaxx motors are not very efficient and therefore are not very good for larger heli-

copters because they generate large amounts of heat. There was one report of an HB

3615-2100 used in an ECO 8, and it became "too hot to touch". The HiMaxx seems to work

okay in microhelis such as the Hornet CP and Zoom. The choice of a motor with a proper Kv

for a collective pitch helicopter is very important, because most motor ESCs are not efficient

when running at much less than 90% throttle. If you run an ESC continuously at low throttle,

the ESC will probably overheat. Therefore, you should select a motor + pinion combination that

will allow the motor ESC to run at 90-95% throttle for best efficiency.

Pole counts for motors are unfortunately difficult to find, and are necessary to program some

ESCs correctly. Here are the pole counts that I have managed to find:

• 2 pole: Hacker, Kontronik, Lehner, some Plettenberg

• 4 pole: Aveox, Neumotor, some Plettenberg

• 6 pole: Mega 16 and 22 series, some Plettenberg

Also see Tohru Shimizu's helicopter brushless motor page at:

www.dokidoki.ne.jp/home2/tohrus/motorindexE.html

Note

Check the length of your motor mounting screws before mounting!

If they go too deep into the motor they will short out a winding which will damage

the motor. Even worse, if you try to run a motor with a shorted winding, it will burn

out the ESC. So test the screw length by screwing it into the motor with your fin-

Helicopter Parts Selection