Create a low-cost power wheelchair from an existing manual wheelchair motorizing it with an electric scooter or a low cost alternative
This project was built during S.T.E.A.M. Fabrikarium in Mumbai. This hackathon dedicated to the development of projects related to disability lasted 5 days. It's a prototype that needs further improvements, but the proof of concept is done :)
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
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.
Find a substitute for the electric scooter motor and the power battery.
- 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.
Create a low-cost power wheelchair from an existing manual wheelchair motorizing it with an electric scooter.
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.
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.
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
Horn Impact resistant waterproof electrical unit Not too much weight gain
Add ons (optional)
Accessory space storage space speedometer headlights
For this scooter model, use a 6mm pipe wrench to unscrew the part we want to remove. On this image the system was mounted before disassembling :)
Once disassembled, you should get the system (in blue on the next picture) not yet mounted on the wheeelchair (not like this picture then ;)
View of the selected part mounted on the wheelchair. To get this result let's follow the next steps.
Prepare a flat steel plate for the wheelchair
The scooter frame needs a support to be attached to the back of the wheelchair.
First you need to measure the width of the wheelchair to cut the appropriate lengthof the steel plate, keeping in mind that you will have to fasten it on the wheelchair. In our case the width of the steel plate was about 2cm and length was 43cm, thickness was 5mm.
Use a metal cutter to cut the steel plate to size.
Take some 8mm screws to attach the steel plate and use the holes from the wheelchair to set it up.
Fix it on the wheelchair before mounting the scooter part (not like this picture !).
Attach the scooter system to the wheelchair via this steel plate
To help positioning and mounting the system, you can use plastic clamps (see picture). It should be updated for the next prototype with something stronger.
Get two bolts 6mm diameters, 30mm length, and attach the system from the scooter to the wheelchair as shown in the circles in the middle of the picture.