hii this is balu.

i had designed my plane of my own... but the whole weight of the plane is 1800gms....

can 3500kv motor lift the plane??

wing span is 1300mm

fuse length 94cm

wing chod 24cm

Kindly give all specs of motor, esc and battery.

motor: 3500 kv titan 450size for helicopter

esc: 30-40a

battery 3s lipo 11.1v

can i use this motor for the plane??

need to know output watts of motor.

here nt mentioned...
operating current:25a
peak current:35a

Do you have a link to the actual product (either from where you bought it, or the manufacturer) ? Most likely we can hunt down the specifications (including wattage/thrust) online, if we know the exact product.

3500 is higher on the KV side, so you will use smaller dia props.  So whether this motor works or not will also depend on the flying characteristics of plane you are building.  This type of motors are typically suited for fast flying ones (like pushers).

Quote from: balasubrahmanyam on October 29, 2010, 11:47:18 PM
here nt mentioned...
operating current:25a
peak current:35a

on a 3 cell pack assuming 11.1V as nominal, the power = 11.1 X 25 = 270 Watts...
At full charge, the motor may draw upto 25 X 12.6 = 315 Watts.

Taking into consideration the weight of the model (1800 gms) and the wingspan (app 52 inches), this may be on the lower side. Try upgrading to a 500Watt motor. That should give you enough power and a good climb.

http://www.topfreebiz.com/product/1627006/Brushless-Motor-30a-Esc-Speed-Controller-T-Rex-450-RC-Helicopter.htm

this is the link...
once have a look and tell me pls...

yes these are my plane specifications..

fuse lage = 94cm
wingspan = 130cm
chord = 24cm
wing shape is semi symmetrical...
weight is 1800gms

i was trying to use a rcforall 2820 brushless motor and 30-40 esc with 11x6" propeller..
is this workable??

Quote from: balasubrahmanyam on October 30, 2010, 10:13:36 AM
http://www.topfreebiz.com/product/1627006/Brushless-Motor-30a-Esc-Speed-Controller-T-Rex-450-RC-Helicopter.htm

this is the link...
once have a look and tell me pls...

Can't find much information on this.  If you go with the voltage x current method (there could be losses and other factors involved), it seems the setup will be underpowered as pointed out by Saurabh.  Plus, you will be forced to use a small dia props on this motor, which is primarily targetting helis.  You may be able to do better with a gear box.  Looks like this one will end up in some experimentation with different small props, with the use of a wattmeter.  Overall, success seems questionable.

Quote from: balasubrahmanyam on October 30, 2010, 10:22:10 AM
i was trying to use a rcforall 2820 brushless motor and 30-40 esc with 11x6" propeller..
is this workable??

If you mean this motor, http://cgi.ebay.in/RCFORALL-BRUSHLESS-OUTRUNNER-MOTOR-A-2820-6-/150502211515 , it should work.  Go for a 40A or higher ESC to be sure. 

One more thing to note...  the KV rating alone cannot determine the "lifting capability" (thrust) of motors.  That is a separate characteristics of motors.  You can have a 3500KV motor with various amounts of "thrust" (when paired with the right props).

yes.. do you have any idea of correct prop size of 3500kv motor??

These high rpm motors usually use props under 6 inches dia.  Something around 5x4 would be a good starting point. You will then have to watch the performance along with current drawn and resultant heat, to see if you want to go higher or lower on dia and/or pitch.  If you can get a datasheet for the motor, it will list the current draw and thrust under various supported props.

This heli motor is pretty high Kv for the model ur building!!!! it is suited for fast models like jets, pushers!!! with say 5" prop, bigger prop may burn this motor and ESC!!!

instead other motor 2820, mentioned, would be rather better option with 3s-4s 2000mA would be best for this model!!!

3s 11.1v lipo and
whats the esc sholud be used???

If you already own the first motor (3500KV one), you can investigate the use of a gear box to support bigger props, such a setup MAY work.  Unfortunately I am not aware of a confirmed way to say which gear ratios will work etc, without experimentation.

i would suggest min 30A ESC, 35A would be better!!!!

If you mean the 2820, the specs listed on that page shows max current of 37A. 

Oops!! i missed it!!! then i think min 45A ESC should be used!!!!so that it will not heat or burn ESC, say for safe operation!!! and yes i would suggest 2500mA battery!!!!

higher KV motor gives speed but thrust i less, so even wattage is high resulting thrust to carry such model may be less compare to lower Kv model!!! in that case gearbox should be used as u hav suggested!!!! :-)