Today's Silly Question - Heli Size

[Talisa]

What is the defining factor that decides whether a heli is a 50,60 90 sized heli? Is there a formula that defines what size a heli is.

For example, I have a GL450SE and a T-Rex 600. What sizes are they. Is it something to do with the length of the rotors?

Told you it was a silly question

T

[Thomas]

50, 60, 90 is engine size - .5, .6, .9 of an inch I think - bigger engine = bigger heli

450, 500 is electric motor size - can diameter I think

[Talisa]

Thanks Thomas