hawkman-RCU

hey guys.
whats a good size motor for a bird of time.im building the kit so i can make any alterations with the fuselage motor mounting.?
basically watts per pound,i would like to run a 11 to 13 inch prop on a 3 cell 2100. like to get a good climb ratio.

thank you for any replies.

BMatthews

A BoT with electric power should be able to be built to end up around 65'ish oz. And based on about 50'ish watts/lb to get a good but not rocket like climb you should be able to do this with a combo that draws about 18.5 amps from a 3S Lipo pack. That's just a hair over 200 watts. To keep the motor cool selecting a motor that has a peak power output of around 250 to 300 watts continuous will ensure you don't run it to the limit and heat the snot out of it. Cooling vents and good airflow are still needed even with such an understressed setup. From there pick one that has a Kv value that suggests that size of prop for running on a 3S pack. But I'd say you're looking at a Kv of 1000 or slightly less to run an 11 inch prop on a 3S pack.

hawkman-RCU

thanks for your input. bmatthews.

aeajr

My Feedback: (2)

I run this motor in my 2M that is about 42 oz. Wattmeter indicates about 280 watts on a 10X7 folder with a 3 cell 2450 pack. I get about 75 degree climb. You should get about a 60 degree climb, Iwould guess. Very happy with the motor. If your battery is a 15Cor higher rated pack it should handle it just fine.

I also run it with 2 cell using an 11X8 for about 200 watts for about a 45 degree climb.

http://www3.towerhobbies.com/cgi-bin...?&I=LXLWU0&P=7

This is the Great Planes ElectriFly RimFire .10
35-30-1250 Brushless Outrunner Electric Motor.



FEATURES: For Sport airplanes up to 3lbs (1360g) and 3D airplanes up to 2lbs
(905g)
Designed for explosive acceleration and maximum torque eliminating
the need for a gearbox
Lightened aluminum can houses high torque rare earth Neodymium
magnets
Double shielded bearings
Virtually maintenance-free; no commutators or brushes to wear out
Two year quality guarantee

INCLUDES: Great Planes ElectriFly RimFire .10 35-30-1250 Brushless Outrunner
Electric Motor
Outrunner Motor Mount GPMG1205
Outrunner Prop Adapter GPMQ4903

REQUIRES: Brushless Motor-compatible 35A Electronic Speed Control
4mm Male Bullet to 3.5mm Female Bullet Adapter (GPMM3123) if using
ElectriFly Brushless Speed Control
Propeller: Depending on aircraft application

SPECS: Motor Diameter: 1.38" (35mm)
Motor Length: 1.18" (30mm)
Shaft Diameter: .16" (4mm)
Shaft Length: .65" (16.5mm)
Lead Length: 3" (76mm)
Connectors: Bullet type, .14" (3.5mm) diameter
Max. Constant Current: 30A
Max. Surge Current: 35A
Max. Constant Watts: 333W
Max. Burst Watts: 390W
No Load Current: 1.2A
Input Voltage: 7.4 - 11.1V (2 - 3S LiPo)
RPM/V (kV Rating): 1250
Weight: 2.5oz (71g)
Suggested Propeller Size: 10x4.5 - 10x7 electric

COMMENTS: The three-number designation refers to Motor Diameter, Motor Length
and kV Rating.

aeajr

My Feedback: (2)

Sometimes the easiest thing is to buy a package that is set up for another plane, but should also work for yours.


Combo-EZGPro-3 (lower section of the page
- Ithink this is about a 300 watt package - should work well with your 2100 battery
http://www.maxxprod.com/mpi/mpi-264.html


Cularis combo
http://www3.towerhobbies.com/cgi-bin...?&I=LXSBS9&P=7

This is the Multiplex Cularis Power Set for the Cularis

This is around a 375 watt package. Might be a bit much for your 2100

FEATURES: Himax brushless motor
BL-37 speed control
Propeller and prop adapter
White spinner

INCLUDES: 1 Himax C 3522-0700
_ 1 MULTIcon BL-37 speed controller (MPUM7276)
1 Propeller driver, blade holder and spinner (MPUA7183)
2 Folding propeller blades, 12" x 6" (MPUA7173)
Hardware
_ Brushless outrunner motor instructions
ESC instructions

SPECS: BL-37 ESC
Number of cells: 6-16
Max current: 37A
Internal resistance: .0045 Ohm
Frequency: 11 kHz
BEC: 5V
BEC current: 1.5A max
Dimensions: 43x25x8mm
_ Weight: 23g

Himax HC3522-0700 Motor
Weight: 5.7 oz. (162g)
Length: 1.89" (48mm)
Max Power: 400W
Max RPM: 20,000 RPM
Motor shaft size: .1969" (5mm)
Motor outside diameter: 1.39" (35.2mm)

hawkman-RCU

thanks for your reply, aeajr.