Joy Stick Control for Mobility Scooter.

I am building a mobility scooter or off road wheel chair for transportation outdoors. Over the last few years I am having more and more difficulty walking due to leg and hip pain. After two back surgery's and like hope of improvement I decided to design and build something that would help me get around outdoors and be able to continue living the life style I enjoy. I am building a three wheel scooter that is going to be powered by two Grin all-axle hub motors with 20" tires on the rear and a 18" caster wheel on the front. The mobility scooter will be steered like a "0" turn lawn mower using a joy stick for each hub motor to control speed forward and backwards. I have not been able to find a joy stick that has "0" voltage in the center (at rest position) and 5 volts all the way forward and 5 volts all the way back. I sure hope one of you guys out there has suggestions on where to find these joy stick or knows how to make them. Any and all suggestions would be greatly apricated!

Hi, i thing there is none joystick that have this function. I thing you need to do some electronic board for it. You need control two controllers - Speed with signal 0-5V, and direction that is digital pin. So that PCB - can be done with opamps,logic IOs etc. Or with arduino if you can write program for it.

Thank you very much for the information.

It does not have to be a joy stick. I was using that as an example. There will be 1 “joy stick” for each motor. The Grin motors I am using has the ability to change from forward to reverse by grounding one wire. I can change from forward to reverse with a switch. So what I am looking for is something like a twist throttle that you can turn forward, from rest, and backwards from rest that will send a 0 to 5 volts in both directions. Thanks again for taking the time to help me with this problem!

Why would you want to build with hub motors not meant for this low speed use? And try to reinvent the (electric) wheel(chair) when these have existed for many years? The very accurate speed and torque control needed for a "turn on a dime" vehicle will be very difficult to master with the motors and separate controllers you've chosen.

I think it would be better to use an existing (second hand) electric wheelchair with brushed, high gear reduction motors and controller and adapt it to your needs. A lot of very good info on that here: http://www.wheelchairdriver.com/

http://www.wheelchairdriver.com/board/

Why does it have to be slow?
Im thinking it could be possible with 2 leavers, one on each side to control that sides motor.

Each lever could be connected to 2 potentiometers with a spring to each potentiometer.
When you move the lever forward one pot stays in the end position and the spring gets more tension.
The other pot moves.

I think it would be funnier with tracks (not sure about the translation?)
Like this:
https://www.youtube.com/watch?v=2cgvB7-XzVs

having two joysticks/potentiometers is also possible but, it will be hard to control it, when you want to go forward you will need to control both same, a little difference of speed for one wheel will starts to turn if your joysticks are in a middle state , you can use some -5V power supply, to add in series with negative wire of joysick, so joystick will have 10V power supply, and controller will have voltage offset 5V, and output of joystick will be 5-10V.

G'day people's
Pity you can't use mobility controllers. The input uses a " wig wag " pot with 2.5 v as neutral, 0v full reverse & 5v full forward. Problem with them is, to my knowledge, that they are only for brushed motors & only in 24v or 36v. 36v is pretty uncommon though.
If someone out there knows otherwise, please share with ES.

AussieRider

I think they make a circuit that takes a single joystick and outputs two motor signals used on fighting robots, but these are mostly RC style signals. Check out the robot websites. This could be done with a fairly simple analog circuit too.