Also see: 700 Comparison Chart
Align TB70 V2Technical Reference • Next-Gen 700-Class Competition 3D Heli |
Model: Align TB 70 V2 - 700 Class RC Helicopter
Category: 700-class high-performance electric flybarless RC helicopter
Primary Intended Use: Extreme 3D aerobatics, F3N international competition routines, precision flight, and high-load sport setups.
The Align TB70 700 combines a lowered center of mass, a heavy-duty belt-drive drivetrain, enlarged swashplate and tail bearings, an internally routed pushrod boom structure, and a 12S-optimized power platform.
2. Contents
- Core specifications
- Airframe dimensions
- Main rotor system
- Main drivetrain
- Tail-drive system
- Power system
- Battery system
- Structural design
- Rotor head and swashplate
- Bearing and shaft information
- Servo installation
- FBL / gyro installation
- Canopy and aerodynamics
- Landing gear
- Headspeed analysis
- Gearing calculations
- Tail-speed calculations
- Rotor loading
- Battery energy calculations
- Real-world configurations
- Vibration and blackbox data
- Low-RPM operation
- Blade selection
- Motor/KV analysis
- Assembly information
- Known hardware
- Kit contents
- Important undocumented parameters
- Technical assessment
3. Core Technical Specifications
4. Airframe Dimensions
| Dimension | Metric | Imperial |
|---|---|---|
| Main rotor diameter (700mm blades) | 1,542 mm | 60.7 in |
| Overall length | 1,356 mm | 53.4 in |
| Overall height | 358 mm | 14.1 in |
| Overall width | 187 mm | 7.4 in |
| Tail rotor diameter (105mm blades) | 279 mm | 11.0 in |
The airframe maintains a compact 1,356 mm overall fuselage length while managing a full 1,542 mm main rotor circle, optimizing disk loading and rotational inertia across all three flight axes.
5. Main Rotor System
The main rotor system uses a 12 mm main shaft paired with a heavy-duty 10 mm feathering spindle. The rotor head features a low-profile center hub designed to bring the rotor disk closer to the center of gravity for immediate cyclic authority.
Primary rotor dimensions
| Component | Specification |
|---|---|
| Main blade length range | 650 mm to 730 mm |
| Included main blades | 700 mm carbon fiber blades |
| Main rotor diameter | 1,542 mm |
| Main shaft diameter | 12 mm (solid precision ground steel) |
| Feathering shaft (spindle) | Ø7 × Ø10 × 97.5 mm |
| Feathering collar hardware | M7 × 15 mm socket collar screws |
6. Main Drivetrain
The TB70 V2 features a dual-stage hybrid drivetrain designed for smooth torque transmission and high efficiency under high-load 3D flight.
| Component | Specification |
|---|---|
| Primary motor belt drive | 22T motor pulley to 50T belt pulley |
| Secondary gear reduction | 15T front main pinion to 62T main helical gear |
| Standard main reduction ratio | 9.38:1 |
| Autorotation tail drive gear | 27T / 28T drive gear to 23T tail drive gear |
| Tail drive ratio | 4.83:1 (with 27T autorotation gear) / 5.00:1 (with 28T option) |
7. Tail-Drive System
Replacing legacy torque-tube arrangements, the TB70 V2 incorporates a belt-driven tail rotor system. The wide timing belt runs inside a rigid composite carbon tail boom, supported by dual tensioner bearings.
| Component | Specification |
|---|---|
| Tail blade length | 105 mm (supports 105–115 mm) |
| Tail rotor diameter | 279 mm |
| Standard tail ratio | 4.83:1 (optional 5.0:1) |
| Tail drive gear | 23T front tail pulley |
| Autorotation drive gear | 27T gear (4.83:1 overall ratio) |
Tail design features
- High-strength belt drive eliminating bevel gear wear and stripping during ground strikes.
- One-piece integrated aluminum tail case with dual control arm support.
- Integrated belt tension adjustment system.
- Streamlined tail fin supporting high-gain pirouette tracking.
8. Power System
The TB70 V2 is engineered specifically for high-voltage 12S brushless power plants, providing brutal power-to-weight performance for 3D aerobatics.
| Component | Standard Super Combo / Recommended Specification |
|---|---|
| Battery configuration | 12S LiPo (Two 6S 4,500 – 5,200 mAh in series) |
| Brushless Motor | Align 800MX (570KV / 4530-class) or 850MX (540KV / 4535-class) |
| ESC | Align RCE-BL130A / RCE-LB130A or Hobbywing Platinum HV 260A V5 |
| Cyclic Servos | 3 × Align DS830M / DS820M HV Brushless (Standard 40mm) |
| Tail Servo | 1 × Align DS835M / DS825M HV Brushless (760µs / 333Hz narrow band) |
| Flybarless System | Microbeast PLUS / Microbeast² Ultra or Rotorflight / VBar EVO |
9. Battery System
The airframe incorporates an integrated sliding battery tray assembly that locks directly into the main frame structure without removing the main canopy.
Nominal battery energy
Operating on a standard 12S LiPo system (44.4 V nominal):
A standard 5,200 mAh 12S battery configuration provides:
10. Structural Design
The TB70 V2 uses an narrow-profile carbon fiber main frame reinforced with CNC-machined aluminum bearing blocks and structural cross-bracing.
Principal structural features
- Narrow frame profile reducing drag and flexing during hard cyclic loading.
- Direct-to-swashplate servo layout eliminating mechanical slop.
- Integrated CNC motor mount acting as a primary structural heat sink.
- Dedicated upper deck for flybarless gyro mounting with anti-vibration damping.
11. Rotor Head and Swashplate
The rotor head features 7075 aluminum grip arms and a heavy-duty swashplate assembly supported by precision radial bearings.
| Component | Specification |
|---|---|
| Feathering spindle | 7 × 10 × 97.5 mm hardened steel |
| Main shaft | 12 mm solid steel with M4 mounting hardware |
| Blade grip thrust bearings | F10-18M (10.2 × 18 × 5.5 mm) thrust bearings |
| Linkage rods | M3.5 heavy-duty turnbuckles |
12. Bearing and Shaft Reference
| Location | Part Specification |
|---|---|
| Feathering spindle thrust bearing | F10-18M (10.2 × 18 × 5.5 mm) |
| Main shaft collar hardware | Socket collar screw M4 × 24 mm with M4 locknut |
| Feathering collar screw | M7 × 15 mm socket collar screw |
13. Servo Installation
The swashplate geometry relies on three 40mm full-size cyclic servos positioned around the main shaft in a 120-degree CCPM configuration, driving turnbuckle pushrods directly to the swashplate.
- 3 × Full-size High-Voltage Brushless Cyclic Servos (e.g., DS830M).
- 1 × Full-size High-Voltage Brushless Tail Servo (e.g., DS835M).
- Direct linkage arrangement eliminating extra pivot points.
14. Flybarless / Gyro Installation
A dedicated composite/carbon gyro plate is mounted on the rear frame structure, isolated from direct drivetrain harmonics. The platform supports all standard flybarless systems including Microbeast PLUS, VBar NEO, Spirit GT, and Rotorflight controllers.
15. Canopy and Aerodynamics
The canopy features a low-drag, high-visibility fiberglass shell with a quick-release mounting latch system. Large air intake vents are positioned directly in front of the motor mount and ESC plate to optimize cooling during sustained high-current maneuvers.
16. Landing Gear
The landing skids utilize low-profile wide-stance composite legs bolted directly to the base frame plates with M4 hardware, providing shock absorption during autorotations.
17. Headspeed and Operating Envelope
The published maximum headspeed for the T-Rex TB70 V2 is approximately 2,400 RPM.
| Flight Mode | Target Headspeed | Context / Application |
|---|---|---|
| Normal / Sport | 1,800 – 1,950 RPM | Extended flight times and smooth aerobatics |
| Idle Up 1 (3D) | 2,050 – 2,150 RPM | General 3D maneuvers and precise tracking |
| Idle Up 2 (Hard 3D) | 2,200 – 2,350 RPM | Maximum collective pop and high-G maneuvers |
18. Main Gearing Calculations
With the standard 22T motor pulley producing a 9.38:1 main reduction ratio:
| Motor RPM (12S ~44.4V) | 22T / 9.38:1 Ratio Rotor RPM |
|---|---|
| 18,000 | ~1,919 RPM |
| 19,000 | ~2,026 RPM |
| 20,000 | ~2,132 RPM |
| 21,000 | ~2,239 RPM |
| 22,000 | ~2,345 RPM |
| 23,000 | ~2,452 RPM |
19. Tail-Speed Calculations
With the standard 4.83:1 tail reduction ratio:
| Main Rotor RPM | Tail Rotor RPM (4.83:1) |
|---|---|
| 1,800 | 8,694 RPM |
| 1,900 | 9,177 RPM |
| 2,000 | 9,660 RPM |
| 2,100 | 10,143 RPM |
| 2,200 | 10,626 RPM |
| 2,300 | 11,109 RPM |
20. Rotor Disc Area and Loading
Using the 1,542 mm main rotor diameter (with 700mm blades):
21. Battery Energy Calculations
| Battery Capacity (12S / 44.4V) | Nominal Energy |
|---|---|
| 12S 4,500 mAh | ~199.8 Wh |
| 12S 5,000 mAh | ~222.0 Wh |
| 12S 5,200 mAh | ~230.9 Wh |
| 12S 5,800 mAh | ~257.5 Wh |
22. Real-World Configurations
Typical stock Super Combo configurations provided by Align include high-grade factory component matches:
| Category | Align Super Combo Factory Specification |
|---|---|
| Motor | Align 800MX (570KV / 4530) or 850MX (540KV / 4535) |
| ESC | Align RCE-BL130A / RCE-LB130A or Hobbywing HV 260A V5 |
| Cyclic Servos | Align DS830M / DS820M HV Brushless Servos |
| Tail Servo | Align DS835M / DS825M HV Brushless Tail Servo |
| FBL System | Microbeast PLUS / Microbeast² Ultra |
| Main Blades | Align 700mm Carbon Fiber Blades |
| Tail Blades | Align 105mm 3K Carbon Fiber Tail Blades |
23. Vibration Management & Tuning
By replacing umbrella gears with a belt-driven tail system, the TB70 V2 dramatically reduces high-frequency drivetrain harmonics. The remaining mechanical noise spectrum is easily isolated using standard double-sided foam tape on the dedicated rear FBL mounting tray.
24. Technical Assessment
The Align T-Rex TB70 V2 represents a modern evolutionary leap for Align in the 700 competition space. Transitioning to a belt-driven tail, dual-stage hybrid transmission, narrow carbon frame, and low-profile rotor head gives the TB70 V2 high mechanical efficiency, quiet operation, and outstanding agility while retaining Align's signature global parts distribution and accessible Super Combo packaging.