Helicopter Collective Control Unit – With Force Feel & Trim System
This is a near-authentic rotary-wing control designed for realism and versatility. It was designed by Karl, a licensed rotary-wing engineer for over 30 years.
 
Many believe helicopters feature true force feedback, but in reality, multi-engine rotor systems demand immense control loads, often exceeding 20 tons. Instead of force feedback, designers implement artificial force units (essentially springs) to simulate the pilot's control feel. This system, known as force feel and force trim, allows precise control without unrealistic forces.
This collective system is designed for serious simulation enthusiasts who demand authenticity without unnecessary complexity. It impressed real pilots at the EXPO in Lelystad—and now, it’s ready for you to explore.
 
Key Features & Innovations
Authentic Design: It is based on the Bell 212 control configuration, with force loadings mapped to the newer, more modern AW139 for a realistic experience.
Stepper Motor Integration: A NEMA 17 stepper motor is the mag brake, parallel actuator, beep trim, and potential autopilot drive unit.
Modular Construction: The interchangeable grip system allows customisation across rotary-wing aircraft.
Functional Force Trim Release & Beep Trim: Trim release provides precise control positioning for large movements, with electrical fine-tuning via the beep trim top hat.
No Force Feedback—Just Realism: Helicopter controls don’t operate via force feedback. Most modern twin-engine rotorcraft are uncontrollable without full hydraulic servo power. Instead, a linear force feel unit (spring) mimics the real aircraft response.
Mapped Controls for Simulation: Though switches are available, most are not pre-assigned, allowing for complete customisation in XP, DCS, P3D, and MSFS.
Build Details
High-quality AW139 grip: Ideal for resin printing for a smooth finish, or available in the webshop.
Universal Compatibility: Designed with a 25mm collective fitting to accommodate multiple aircraft grips.
No complex software—just Mobiflight! The unit functions as a standard PC joystick using a Leo Bodnar card.
Printing Requirements: This project requires a 300 x 300mm print bed (e.g., Creality CR10 or similar). This design may require adjustment as modern printers have much better print tolerances than the CR10. For this, I recommend the CAD Version!
 
Frequently Asked Questions
Is there a Small Printer Mod (SPM)?
No. You will need CAD and STL versions to manually split the design.
Are laser engraving files included?
No. You must extract DXF files from the CAD version.
Can I build this without the stepper motor?
Yes. But without it, trim hold and force feel will be absent, reducing realism.