What are the sizes for the calssifications used here?

[Ozzyeureka]

OK, what is small, medium and large electric helis? I know it will be by rotor diameter, but what are the boundaries/limits for each class?

What does a Walkera #4 fit into?

[eddiemoth]

Ozzyeureka,
Walkera 4's total max weight is 350 g. So it is a micro and can be discussed here.

Technical Parameters

Main Rotor diameter: 510 mm
Length of airframe: 470 mm
Main motor: Powerful 280 main motor
Maximum flying weight: 350 g
Tail motor
Number of channel of transmitter: 4 channel
Power supply: 8.4V 750mAh NI-MH rechargable battery

[Ozzyeureka]

Ok, so the classifications are by weight. So what are the limits for each class?

[eddiemoth]

There is no official exact weight limit for classifications but these are kinds of a guideline to organize discussions so we all can find the info easily. Normally a mini heli weighs more than 400g. and less than 800 g. and big electric heli normally weighs more than 800g and a sub micro heli normally weighs less than 150 g. Thre is no weight limit for coaxial heli forum. We classify gas/nitro by manufacturer. It is a good question and I hope this would help clarify it.