O-trotti (Steam Fabrikarium)

Last day of the Fabrikarium, we made a test with Druv' : Success :)

We decide to split the team for different missions:

1 - Find a way to attach the blue scooter

Issue: with 5 wheels the system could be hyperstatic, so there are risks that the motorized wheel is not efficient in case of hole on the road.

Solution: use a metal rod harness at the back of the wheelchair as a support to attach the scooter. For a better adherence of the 5th wheel on the road, we bended the metal rod to be sure that the wheel presses on the road

Other solution (given up meanwhile):

As the mechanism fell into place we figured out  the customized joinery that would connect the trotti to the wheelchair. These were modeled on fusion360 and are open source available in the file section of this project.

Issue: not resistant enough, very long print

2-Electronic alternative

As the scooter is quiet expensive, the goal is to create a motorized system that could replace it.

A team works on finding a low-cost alternative including battery, Arduino and motor controller.

3-Mecanic alternative

Find a substitute for the electric scooter motor and the power battery.

Issues:

- Attach the wheel on the motor

- We used a plastic wheel and it should be better to use rubber one.

- Attach this system on the wheelchair

4- Ajay's wheelchair issue

Ajay already built a trotti by himself but as he got a new wheelchair, he would like to adapt his system on the new one and faced issues to attach it.

On its original system he also had difficulties to screw and unscrew it.

DAY 1

Goal

Create  a low-cost power wheelchair from an existing manual wheelchair motorizing it  with an  electric scooter.

User study

To specify needs regarding this project, we made an audit of 4 disabled people using wheelchair who were part of the team .

From the interviews we concluded that 3 out of 4 could use manual direction. The 4th interview was a girl with muscular dystrophy and hence depended on a joystick.

We were looking at two different categories of disability and had to narrow down to a more specific target segment.

Target segment : people who use the wheelchair and have body strength as well.

Specifications:

Design a universal, and cost-effective power attachment to convert a manual wheelchair to an automated power wheelchair based on an electric scooter.

3 of the 4 people did not want to have the electric scooter handlebars in front of them, so it was decided to put the motor with a 5th wheel at the back of the wheelchair and to control direction of the wheelchair with hands, including braking.

Primary needs

Comfortable
stable
Foldability of the wheel and the wheelchair unaffected
Easy to drive
5th wheel should be thick 
Can be easy to attach and detach

Universal

Secondary needs

Horn
Impact resistant
waterproof electrical unit
Not too much weight gain

Add ons (optional)

Accessory space
storage space
speedometer
headlights