Developing the Folding 3-Wheeler

March 6, 2007

Background/Justification

• Allow user to gain access to public transportation.

• Facilitate the process of transporting the user and the wheelchair safely.

Goal

• To design a folding three wheeled wheelchair that has the kinematic advantages of a 3-wheeler, but the portability of a folding 4-wheeler.

Original Functional Requirements

• Fold compactly when not in use• Be comfortable and ergonomic• Light enough so the user can carry it

But then…

Primary Functional Requirements• Ability to fold compactly• Made from cheap and available materials• Easy to manufacture• Sturdy

Design Parameters

Cheap and Available Materials

• Design constraints Joints must be prismatic or revolute. Use of only 25mm pipe. 26” wheels. Limited tool set.

• Design Freedoms Use of bike parts

Easy to Manufacture

• Timeline to completion: 3 days Can extend production time to 4 days.

• Cost vs. Benefit

Sturdy

• Sacrifice portability for rigidity?

Current Brainstorming/ Strategies

Countermeasures

• Modularity Easily detachable features “snap together” Only uses one “extra” tool

Questions?