Helicopter sizes

[bcphill]

OK my first technical question after joining the site - hope its in the right section

I,m trying to find out what the sizing of helis refers to. Some say they have a 450 or a 500 and of course I assume the bigger the number the bigger the aircraft but what is actually being measured.

Is it the rotor length or something else

Phill

[Boony]

The number convention has come about with electric helicopters, it is meant to be the length of the rotor blade the helicopter swings...

[AlastairC]

OK my first technical question after joining the site - hope its in the right section

I,m trying to find out what the sizing of helis refers to. Some say they have a 450 or a 500 and of course I assume the bigger the number the bigger the aircraft but what is actually being measured.

Is it the rotor length or something else

Phill

This is a good site that discusses this (and many other things RC Heli related):
Large RC Helicopters Or Small - How to Figure It All Out

Hope this helps.

Cheers,
Alastair

[bcphill]

Thank Guys all a bit clearer now

Phill

[Peteski]

This webpage gives a good quick overview of how the various sizes compare relatively. At a glance 450 to 500 looks like a big jump.

Helicopter - Align

[trillian]

Basically once you reach the 550 size the number pretty much match the size of the blades, so 550 = 520 to 550mm blades, 600= 600 to 620mm blades, 700= 690 to 720mm blades and so on.

The common sizes that don't conform to this forumula are 450 and 500.

450 size helis run blades between 315 and 350mm
500 size usually run blades of about 425-430mm except the Goblin 500 which uses bigger blades (470 - 500mm)

Takeoff weights can vary a bit but are roughly something like:

450 - just under 800 grams
500 - about 2kg
550 - right around 3kg
600 - about 3.6kg
700 - 5kg give or take a bit depending on packs etc.

[Bob H]

The actual numbers of all the original Align electric helicopters (where the basic electric class numbering comes from) follow the convention set by nitro helicoptors in indicating model class by motor size. A 450 uses a 450 electric motor, a 500 uses a 500 electric motor, etc., etc. The common confusion in size demarcation, as trillian has already pointed out, happens at 550 class and above where the blade length and motor size starts to correlate with each other. It's further confused by initially GAUI (with the X5) and followed on by SAB and others where the manufacturers use the designed blade size not the motor size.

It's all got to be a bit of a mess now but the electric model size demarcation convention outside of Align is now almost entirely purely by main blade length while Align continue to classify by motor size - although with the larger Dominator kits Align are now starting to move away from that practice as well.

[goldslinger]

this might help with sizing it was something I was puzzled over

1:MINI RC HELICOPTERS

· Rotor diameter range: 150mm – 300mm (6inches – 12 inches)
· Electric motor size: 100 - 200 series
· Combustion engine size: Too small fornitro or gas

2:MICRO RC HELICOPTERS

· Rotor diameter range: 300mm – 600mm (12inches – 24 inches)
· Electric Motor Size: 200 – 300 series
· Combustion engine size: 0.049nitro(very rare)

3:SMALL SIZE RC HELICOPTERS

· Rotor diameter range: 600mm – 1100mm(24 inches – 44 inches)
· Electric Motor Size: 400 – 500 series
· Combustion engine size: 0.10 – 0.20(10-20 nitro)

4:REGULAR SIZE RC HELICOPTERS

· Rotor diameter range: 1100mm – 1500mm(44 inches – 60 inches)
· Electric Motor Size: 550 & 600series
· Combustion engine size: 0.3 – 0.6(30-60 nitro)

5:LARGE RC HELICOPTERS

· Rotor diameter range: 1500mm and up (60inches and up)
· Electric Motor Size: 700 and up
· Combustion engine size: 0.70 and up (70nitro) - 20cc and up (gas) - 6 hp and up (turbine)