Neodymium magnets - strong magnetic
field produces exceptional motor torque
Kevlar sleeve on rotor allows 40,000
rpm
Efficient rotor design supported by
sealed ball bearings for long life
Flow-through cooling for reliable
operation at high power levels
Exceptional versatility - from 6 to
12 cells direct, and 6 to 16 cells geared (depending on wind)
Fitted with 16mm / 19mm mounting
holes and 3.17mm motor shaft to fit many motor mounts and gearboxes
Motor Type
#Cells
No Load
Amps
m W
Kv
Short Time
Max Amps
Weight
ACn 16-15-3
6-14
1.70
27
3000
30
76g
The Mega 16/15/3 is a 3000kv brushless motor. It is regarded as one of
the more capabable power sources for the T-Rex and has a reputation for
delivering considerable power but at the expense of high amp draw.
In conducting the tests on this motor I decided that I would run an initial
mini-test using the 13T pinion, this will yield a head speed below the
maximum 2400 rpm for the standard wood blades.
Suprisingly the graphs are not massively dissimilar in terms of amp draw
to the Align 400S using the 13T, although the Mega did pull more amps overall
it was only 1.2 amps greater at its maximum draw for the course of the
test.
As per all motor tests the lipo used was the Tanic 3S 2220mah and the graphs were created using the Medusa Power Analyser Plus.
The test was conducted as follows :
Time period
Activity
90 seconds
Spool up and hovering throttle/pitch (mid stick)
30 seconds
Full power / full pitch
30 seconds
Hovering throttle/pitch (mid stick)
30 seconds
Pitch pumping from full negative to full positive pitch
60 seconds
Hovering throttle/pitch (mid stick), spool down
The recorded maximum values for the duration of the test were the following:
The recorded minimum voltage was 9.7 volts during the 30 second full throttle/pitch.
After some more testing I've decided to stick with the 13T pinion on the
Mega. This was based on some full power tests to look at the reduction
in RPM as well as realising that at 95% throttle the Mega was producing
a head speed of 2450 RPM. Going to a 14T pinion would just load the motor
further and result in a greater headspeed loss in 3D flight.Using stock
wood 315mm blades I had an RPM decrease over 30 seconds of 320 RPM from
the initial 2450 RPM.
I performed the RPM loading test using the Phonenix 35 governor mode with
a set 0 degrees pitch RPM of 2450. After 30 seconds the speed had crept
down slowly to 2130 RPM. However, it should be noted that initially the
motor and lipo coped quite well with this loading with around a 280 RPM
drop in headspeed which then sunk slowly to the measured 2130 RPM.
In flight the Mega has plenty of power for 3D flips and good climbouts.
I have been particularly impressed with it's ability to take very significant
loading on the heavy Align Carbon Blades and at times it drew 26amps from
the lipo! Clearly this would lead to much reduced flight times, usually
around the 8-9 minute mark.
Overall I think the Mega is a great non-specialised motor for the T-Rex
that provides good power and reasonable flight times depending on the blades
used. I refer to the Mega as non specialised as it has been out for some
time and is a multi-application motor, more typically seen on aircraft
than heli's. It is this multi use, non specialised feature that makes the
Mega relatively easy to source and prices are very reasonable for the performance
given. It will be interesting to see how the Mega compares to the more
specialised motors now appearing that have been designed with applications
like the T-Rex in mind.
