Helicopter Cyclic Control System — STL FILES ONLY (Bell 212‑Inspired Force‑Trim With Magnetic Braking)

Introducing our meticulously engineered Helicopter Cyclic Control System — STL FILES ONLY, one of our most advanced and realistic flight‑sim hardware designs to date.

YouTube video:https://youtu.be/vC68XzT6nMo

Built on 28+ years of real-world helicopter experience, this system reproduces the true mechanical feel of rotorcraft controls—especially the notoriously difficult-to-replicate magnetic clutch/force‑trim mechanism found in aircraft like the Bell 212.

This is a purpose‑designed system for sim‑builders who want professional‑grade realism in cyclic operation, not a simple gaming controller or force‑feedback gimmick.

What's Included (Downloadable STL Files)
You will receive STL files for:

Cyclic base assembly
Parallel actuator + linear force‑feel units
Magnetic braking stepper housing
Series actuator (autopilot drive) housing
Bell‑212‑style cyclic grip

Includes: trigger components, top‑hat beep trim, spring plate, button guard, LHS/RHS grip shells, and mechanical trigger elements

All required structural & mechanical 3D‑printed parts needed to build the complete physical system shown in the photos

Note: This product contains only STL files. No CAD, STEP, Fusion, or hardware files are included.

Key Features
Realistic Magnetic Force‑Trim System

Powered by a standard NEMA 17 stepper motor to simulate magnetic braking
Allows realistic force‑trim repositioning, holding, and fine‑tuning
Performs like true hydraulic‑servo‑based helicopter controls—no artificial force feedback

Parallel Actuator System (Force‑Feel Units)

Springs provide the correct linear force feel, just like modern twin‑engine rotorcraft
The stepper motor drives the datum point for accurate force‑trim behaviour
Springs are user‑replaceable for custom resistance strength

Bell 212 Force Profile

Accurately simulates the cyclic feel of a Bell 212HP with force trim enabled
Reflects real operational preferences: many 212 pilots hover, take off, and land with trim OFF for fine precision, then re‑engage trim for cruise stability

Included Button Controls (Mechanical STL Parts)

Trim release switch
Beep‑trim four‑way top hat
Cargo release (wired but unused by default)
ICS/Transmit dual‑point trigger (mechanically functional, wiring optional)
AFCS release (wired but unused)

Operation Overview

Trim Release: Press to reposition the cyclic to any neutral point. Release to “lock” it in place using magnetic braking.
Beep Trim: Micro‑adjust the cyclic centre point with precision.
Force Adjustment: Swap to stronger springs for heavier cyclic forces.

Compatibility

Grip Mount: 25 mm fitting (compatible with many aircraft grips—helicopter, rotary‑wing, and fixed‑wing).
Simulator Support: Works seamlessly with

MSFS
DCS
X‑Plane
P3D

Electronics Integration:

Works with Mobiflight
Axis/buttons via Leo Bodnar/Arduino Mega (or equivalent USB interface)

Printing Requirements

Minimum print area: 300 × 300 mm (CR‑10 or similar)
Tolerances:

Original design targeted CR‑10 tolerances
Modern printers may require slight fit adjustments (±0.2–0.4% scaling or hole tuning)

Suggested Print Settings
Structural parts:

PETG / ABS / ASA
0.2 mm layer height
4–6 perimeters, 35–50% infill

Grip:

Resin printing recommended for the smoothest finish
FDM alternative: 0.12 mm or finer

Build Guide & Reference Material
Full build guide (mechanical assembly, parts list, wiring reference):
🔗 https://www.737diysim.com/build-guides-1/bell-212-heli-cyclic
Hall sensor upgrade & calibration guide:
🔗 https://www.737diysim.com/post/cyclic-hall-sensor-mod