Mechanical

Mechanical Overview

Table of Contents

• TL:DR
• Hand Mounted
  • Backplate
  • Thumb Base
  • Finger
• Arm Mounted
  • Servos
  • PTFE Tube

TL:DR

The mechanical system of the Dewclaw project consists of two main subsystems: the hand-mounted subsystem and the wrist-mounted subsystem. The hand-mounted subsystem includes the thumb and occasionally sensing components, while the wrist-mounted subsystem incorporates control interfaces like motors and microcontrollers.

Hand Mounted

Backplate

• Function: Secures the thumb base to the hand and connects to the thumb base via three elastics.

Thumb Base

• Function: Forms the first joint to the thumb and is held in place by the backplate.
• Features: Includes a port for the PTFE tube, which guides control lines through it.
• Components: Houses the base for two springs - the adductor spring and the final joint spring.

Finger

• Structure: Each finger segment includes two wire guides on the inner surface, except for the tip.
• Springs: The backside of each finger segment is equipped with springs.
• Base Knuckle: The base knuckle is a universal joint, with the adductor spring connecting to the outside of the base knuckle.

Arm Mounted

Servos

• Placement: Mounted on the wrist mount.
• Components: Equipped with two half pulleys to control wires connected to the thumb.

PTFE Tube

• Function: Guides the control lines, ensuring a constant distance from the servo pulleys to the thumb.
• Benefit: Ensures that thumb movement remains unaffected by the position of the hand.