What type of motor is best for powering a homemade helicopter?

[Austine-J5]

Hello guys, I have a project I intend to embark on,actually it a helicopter,but I still can't figure out the best type of motor to power the blades of my design. I need something light,small and POWERFUL. I look forward to your contribution.
Thanks in advance.

 

[Simon Bridge]

Welcome to PF;
Small and powerful is right - you want it to be light, but a powerful motor also needs a bigger energy store, and that will add weight as batteries or fuel, or decrease the range.

Have you tried looking at what other people have tried?
Have you tried a model-helecopter forum online?

The way to approach this sort of thing, as an engineer, is to list the desired properties, and then canvass the manufacturers. Compare models of motor in a weighting chart to narrow down your options.

Right now your question is too open ended for anyone to give you an informed suggestion.

 

[Austine-J5]

I'll keep to your advice. Thanks a lot

 

[Austine-J5]

I tried but its like looking for a fish in an ocean. Do you know any of such forums? The ones I saw do not involve constructing anything rather how to fly the one they bought.

 

[rcgldr]

Why not use the motor, recommended battery, and gearing from an existing model helicopter that has a similar rotor size and weight as your model?

 

[NavinRJohnson]

That is a pretty vague question but, you'll likely want to go with a brushless DC motor and controller for the best weight and efficiency.
The harder part may be trying to figure out how much power and RPM your motors will need to spin the prop/prop's you use. Have you picked a prop? Have an all up target weight? How many rotors?

IMHO, it's easiest to pick a prop of proper with known specs first, find the proper motor to drive that and then design the rest of the model around it. Make tweaks to step 1 and 2 if necessary.
The folks at the following link will have good info for you
http://www.rcgroups.com/forums/index.php
Have a visit to the electric heli and airplane forums, they have some good info on thrust output of many popular prop/motor combinations. It's a pretty friendly and mostly DIY community that should be able to give you a good start.

In the interim, here is a link to a hobby website that has plenty of motors at reasonable prices. Just looking at brushless "inrunner" motors you have thousands of choices.
http://www.hobbyking.com/hobbyking/store/index.asp

 

[Simon Bridge]

That is a pretty vague question but, you'll likely want to go with a brushless DC motor and controller for the best weight and efficiency.

... very vague - we don't even know that an electric motor is desired - model helecopters can use internal combustion engines too.

Hmmm... steam-engine helicopter...

 

[Simon Bridge]

I tried but its like looking for a fish in an ocean. Do you know any of such forums? The ones I saw do not involve constructing anything rather how to fly the one they bought.

Try looking for one attached to a model flying club.
http://forum.medwaymfc.org.uk/view_forum.php?id=11
... just an example, not a recommendation, but these guys talk about building models.

 

[rcgldr]

Just looking at brushless "inrunner" motors you have thousands of choices.

I think it's more common to use "out runner" brushless motors, since they operate at lower rpm, requiring less gearing reduction to drive the main rotor.

 

[Austine-J5]

I have carried out a few researches and so far I have been able to narrow my list down to 5. But am still comparing their specs. Hopefully I should be able to end up with a good one. But I saw something alarming...OVER A HUNDRED BUCKS! Can you imagine. That is really really high.

 

[256bits]

Make your own from a CD player.
http://www.angelfire.com/blues/heli_project/brushless.htm