Paraglider Trike Frame and Stick Control Linkage

Alex Frye

ENGR3330 Mechanical Design

Olin College of Engineering December 9, 2021

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Design description:

Trikes are three-wheeled buggies for powered paragliding. They provide a mounting for the parafoil, paramotor, and harness, eliminating for the pilot to be directly attached to these heavy components.

Mechanical control sticks are often found on older aircraft and modern small aircraft. They act as the interface between the pilot and the aircraft’s pitch and roll controls (typically elevators and ailerons, respectively).

Paragliders are controlled by pulling on break lines which deform the outboard trailing edges of the foil, incurring drag, and governing coupled roll-yaw behavior. Limited pitch control and stall behavior can be achieved through pulling both brake lines simultaneously.

SolidWorks Assembly of Design:

The trike consists of a tube frame steerable nose wheel (with cam-actuated brakes), and a stick-actuated control linkage which extends/retracts control rods. Eyelets provide hitch points for the break lines, which are routed through the pulleys, and up to the parafoil.

FBD of Frame:

Load Case and FBD:

Force Analysis:

Impact force calculated from descent under a Companion SQR 120 reserve chute at max weight (120kg) at 5.4m/s with 4in (0.1m) wheel compression.

FEA of Frame:

vM Stress

• Max: 4.431e8 Nm^2
• Yield: 4.7e8 Nm^2

FoS

• Min: 1.061

Deformation

• Max: 3.2 mm

FBD of Rear Axle:

FBD :

Force Analysis:

Fa1y

Fa2y

Y

X

R0y

FEA of Rear Axle:

vM Stress

• Max: 2.047e8 Nm^2
• Yield: 4.7e8 Nm^2

FoS

• Min: 2.3

Deformation

• Max: 0.62 mm

FBD of Steering Column Plate:

FBD :

Force Analysis:

Y

X

FEA of Steering Column Plate:

vM Stress

• Max: 1.225e8 Nm^2
• Yield: 4.7e8 Nm^2

FoS

• Min: 3.746

Deformation

• Max: 0.2685 mm