The Swanbot Gripper was designed, simulated, and 3D printed by Corbin Grubb for an engineering course. It uses a compliant gripper mechanism made of flexible plastic to grip a 4"x4"x1/4" steel plate using a 9 gram servo motor, maintaining its grip without input torque. The design has minimal moving parts and allows the gripped plate's torque to not affect the servo motor.

1. Swanbot Gripper
Designed, simulated, and printed by Corbin Grubb
Created for RBE 2001

2. Design Goals
• Must be able to hold and release a 4” by
4” by 1/4” stainless steel plate
• Must need no input torque to maintain
grip
• Must require no more than 0.25 kg/cm
of torque at any point
• Must only have one degree of freedom
• Minimal moving parts

3. Features
• Lower plate ( 1 ) supports weight
of the target plate
• Compliant gripper “claw” ( 2 )
prevents plate tipping or sliding
off lower plate
• 9 Gram servo motor ( 3 ) actuates
gripper
• Two bearings in the rear ( 4 )
attach to rest of Swanbot
( 3 )
( 1 )
( 2 )
( 4 )

4. Simulation of flexible gripper
Scale represents displacement
Maximum force of 1 newton
Compliant mechanism

5. Benefits of design
• Torque from plate is not
transferred to servo motor
• Compliant gripper defaults to
closed shape without input torque
• Entire assembly has two moving
parts, excluding servo motor horn

6. Implementation
• Compliant gripper part 3D
printed in TPU plastic
• Gripper body and servo
lever printed in ABS
plastic
• 3 mm steel rods used as
guide rails to prevent
twisting

7. Swanbot performing its duty
Gripper in action