800 Size RC Helicopters: Rotor Sizes, Scale Fuselages and Power
“800 size” (often called 800 scale) RC helicopters use main blades of roughly 750–810 mm, giving rotor diameters around 1.66 to 1.78 m. Examples include Align’s T-Rex 800E with 780 mm blades and a 1,740 mm rotor, and scale models such as Roban’s 800-size UH-1D with a 1,660 mm rotor. They fly smoothly, look impressive and are popular for big scale fuselages, but they’re expensive and need experienced pilots, big batteries or gas engines, and a proper flying site.
By Kyle HilsonUpdated: October 20263 min read
What 800 size means
| Example | Blade length | Rotor diameter |
|---|---|---|
| Align T-Rex 800E Pro | 780 mm | about 1,740 mm |
| Roban UH-1D 800 (scale) | 750 mm | about 1,660 mm |
| Typical blade options | 760–830 mm | about 1.66–1.78 m |
From maker and dealer listings, checked October 2026. Size classes are explained in RC helicopter sizes explained.
Why fly an 800
A large rotor moves slowly and smoothly through the air, so an 800 looks realistic and stays steady in wind. It’s the size where scale fuselages start to look truly convincing, with room for detailed cockpits, lights and multi-blade heads. Sport and 3D pilots like the big, graceful manoeuvres. The cost of crashes, batteries and parts is high, so most 800 pilots have years of experience on smaller helicopters.
Power options
- Electric: high-voltage systems (commonly 12S or more) with large-capacity packs; clean and quiet but battery costs are high.
- Gas: 2-stroke petrol engines in some 800-class and scale helicopters; long flights and cheap fuel, more vibration and maintenance.
- Turbine: used in some large scale builds; the most expensive option.
800 scale fuselages
Roban and others make 800-size fuselages of helicopters like the UH-1D Huey, which fit compatible mechanics and add four-blade or two-blade scale heads. These builds are heavy, sometimes needing special approvals, and take weeks to set up. Even larger helicopters exist as one-off projects; see the world’s biggest RC helicopters.
Before moving to an 800
- Fly a 600 or 700 helicopter confidently in all orientations.
- Learn flybarless setup and governor tuning.
- Budget for batteries, chargers and spare blades.
- Find a site and club that allow helicopters of this size.
- Check local registration and weight rules.
Safety
- Blades carry huge energy; keep a big safety distance.
- Use throttle hold and arm only at the pad.
- Check blade grips and bolts before every flight.
- Handle high-voltage packs carefully.
- Never fly near people or over pits.
Costs
An 800 complete with electronics and a couple of battery sets costs several times a 450 or 550. Blades alone can cost more than a small helicopter. Many pilots buy used 800s, but servo age, battery health and frame condition must be checked carefully.
Transport and setup at the field
An 800 with blades removed still needs a big car boot or van, and the blades travel in a padded bag. At the field, assembly includes fitting and tightening blades to the correct torque, checking the governor and battery voltage, and doing a careful pre-flight check. Many pilots bring a folding table and a dedicated stand to make this quicker and safer.
Blades
Use blades of the length and weight the maker recommends, since they change head speed and power draw.
FAQ
What is an 800 size helicopter?
One with roughly 750–810 mm blades and about 1.7 m rotor.
Are 800 helis gas or electric?
Both exist; electric is common for sport, gas for some scale.
Is an 800 good for beginners?
No, it’s for experienced pilots.
What battery does an electric 800 use?
High-voltage packs, commonly 12S or more.
More on this topic: the complete RC Helicopters guide covers the basics behind this article.
About 20 years in RC. Mostly boats in the NAVIGA Mini Eco Expert class, with many self-made parts; also a King Motor Baja 5B, a home-built electric plane, home-built nitro planes he has flown, and an RC helicopter. More about SwellRC
