Ahhhh, my favorite robot of all time. I am building a mini version from the 2 foot remote controlled toy . I have read in the forums where one person took the joystick controller for the wheelchair and just hooked up two servos to it, and those were controlled by the EZ-B. That is the simplest way. I am sure there is an electronic way, I just don't know it.

I love your B9. Linky

Hmmm. So simple, it never occurred to me... I'd rather have an electric solution but I'm not above a little 'creative engineering'.

Thanks!

At the top of the Community page you can do a keyword search - I think there are some electronic solutions on here somewhere.

Hello Gwen welcome along Recently I modified my second motorised electric wheelchair to be controlled by EZ-B While I would have preferred to take the joystick controller apart and use some type of interface I decided after some research to simply use two servo motors which I connected directly to the joystick now I even have voice control of the motors. The controller I have has an integrated joystick ,while the controller and joystick in your wheelchair are possible seperate, it may be possible to take it apart and interface.

While you could add seperate controllers for the motors, remember you have possibly one of the most advanced controllers already in your chair

only components necessary, 2 servo motors which connect directly to Ez-b Pat

Hi Pat, Thanks so much for your reply. I hoped to interface directly but I'm certainly not above the 'creative engineering' solution. It's looking more & more like that will be the way to go. There doesn't seem to be any specs available on the web...

Do you have any pictures, notes or other documentation that might help me figure out how to make two servos move the joystick through it's full range on both axis?

Thanks in advance!

@Gwen

I too was trying to make a remote control wheelchair. Like yourself, I considered using the Sabertooth but thought, why not try and use the controller on the chair. I worried about hacking the joystick/controller and burning it up, as it was important to me to keep the chair fully functional as someday these old bones might need it ... lol. I did run across several ideas but while looking into it I found this site and put the chair on the back burner. EZ Robot is such a GREAT product I just had to have one and now I'm hooked. I do plan on getting back to the chair this winter. Here is a link you might be interested in reading. In this project a guy hacks into a joystick/controller (same one I have) and shows how he did it. Maybe you can get some ideas out of it.

http://mowstation.blogspot.com/2011_09_01_archive.html

Below is a picture of one way to use servos to control a joystick. Thought about using this setup myself or at least giving it a try. I planned on taking the joystick out and mount it on some plexiglass along with the servos. Don't know how it would work but it sure seems simple enough to try.

Anyway, please keep us up to date on your project.

Herr Ball

The direct alternative is use a high amperage motor controller. The Sabertooth 2x25 is an excellent choice for wheelchair motors and some of the users here have some experience with it, and I believe the latest ARC version even has a Sabertooth Movement Panel specifically for this board (I have had to set my project aside for a couple of months, but plan on starting up again in a few weeks, and this is the direction I am using. Have the motors and wheels, but no Joystick).

You could also use two Parallax HB25's as controllers, and they look just like modified servos to ARC. There are some other choices, but those are the best I have seen at a decent price point (<$125).

Alan

I just re-read your first post and see that you looked at the Sabertooth 2x60. 2x25 should be sufficient for wheelchair motors and costs a lot less. I have never heard of anyone needing 60 amps except for ultra-heavyweight battle bots where you need both high weight handling and high speed.

Alan

Thanks!

Gwen Attached some photos of joystick control by EZ-b

I extended the shaft using a box spanner( cut the handle off) ,fits tightly over original short joystick shaft and is held down by a simple plate with two screws.

Both servos are mounted on basic hinges which allow them to sway back and forth.

each servo has a long lever shaft one approx 1" longer.

Over time I have found it very stable and there is little load on the servos, with the extended shaft.

Pat

Hello Gwen, welcome to the forum. I would recommend removing the wheel chair controller and replace it with a Sabertooth Motor Controller. EZ-Robot and some kids built a robot from a wheel chair base for the Western Canadian Robot Games. It used a Sabertooth 2x50 and ran the motors with ease :)

There is support for the Sabertooth Motor Controller in ARC.

Hi Gwen,

A few questions, is your chair fully functional right now ( as in joystick controls works )

if so could you open up the joystick controller and send some a pictures of the insides.

I have managed to interface my controller and still have the chair working normally with the joystick.

It is a simple and inexpensive solution and uses existing hardware.

Dave.

Hey Putt Putt

Could you send me a email. I would like to discuss this further with you.

Thanks ... Herr

Herr Ball,

I sent you an email asking what you would like to know......but not sure if my email is working.