# Repurposing Arrow Mobility Scooter/Chair



## Salty9 (Jul 13, 2009)

I am considering converting a mobility scooter into a Segway type device if possible or failing that into a tractor for towing a garden wagon. Anyone here done something similar or have advice?


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## Ziggythewiz (May 16, 2010)

I've seen some awesome RC mowers...


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## Salty9 (Jul 13, 2009)

I was thinking RC also but, thank the lord (if she exists) I don't have a lawn. I think lawn grass is the most noxious weed.


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## Ziggythewiz (May 16, 2010)

You'd like it in Houston. We just let the weeds fill in the space around our houses, and mow em when they get to high. Then we call it grass. They're only weeds if they're over 10 inches.


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## Woodsmith (Jun 5, 2008)

Salty9 said:


> I am considering converting a mobility scooter into a Segway type device if possible or failing that into a tractor for towing a garden wagon. Anyone here done something similar or have advice?


Is this a poll?

I vote for a tractor type thing!



Seriously, turning it into a tractor will be easier and more fun and productive IMO. It saves all that gyro stabilizing stuff and you can do stuff with it.


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## Salty9 (Jul 13, 2009)

Woodsmith said:


> Is this a poll?
> 
> I vote for a tractor type thing!
> 
> ...


I think you are right Woody. I picked the chair up today and at first look it looks like it wants to be a tractor. It looks way overbuilt. They must be selling these things by the pound. I had a Jeep pickup that was flimsier than this chair.


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## Salty9 (Jul 13, 2009)

Been playing with the chair bottom and found that the joystick is broken and the controller has a controller chip requiring a manufacturers programmer to make it useful. I am considering using this chip as a driver for a controller. http://www.digikey.com/product-detail/en/A3985SLDTR-T/620-1180-1-ND/1242942

The chair has 24V batteries and 2 brushed geared motors. Anyone have any experience with or thoughts about this or similar control chips?


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## PStechPaul (May 1, 2012)

That looks like a pretty good controller for two motors. However, it's designed for two phase stepper motors and I'm not sure you can drive two motors separately. It requires a microcontroller with an SPI interface which can be tricky. 

A better choice may be the http://www.digikey.com/product-detail/en/A4940KLPTR-T/620-1319-1-ND/2042755, which is an automotive full H-bridge MOSFET driver. You would need two of these but they are only about $3. Your microcontroller would provide direct PWM drive signals.

Here are other similar products:
http://www.digikey.com/product-detail/en/HIP4080AIBZT/HIP4080AIBZTCT-ND/1034096
http://www.digikey.com/product-detail/en/A3941KLPTR-T/620-1236-1-ND/1829847

I have used a gaming joystick for motor control so if you need some ideas I can help.


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## Salty9 (Jul 13, 2009)

Thanks Paul. I looked at the A4940 chip and thought the dual bridge might be simpler but I think I will use the A4940. The joystick sounds like a fairly simple control mechanism.


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## aishah (Jan 7, 2014)

Hi Paul,

I am newbie in this forum, and I saw interesting post of you. 
Need your guide on controlling using joystick. 

Thanks


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## PStechPaul (May 1, 2012)

Look for joystick circuits, and get one to play around with. Here is some information I found quickly:
http://www.epanorama.net/documents/joystick/pc_circuits.html
http://www.discovercircuits.com/J/joysticks.htm
http://www.4qdtec.com/jsi.html

The circuit I made converts the voltage from the joystick forward and reverse (fore and aft) to a voltage that works for the VFD I have. If you want to use the joystick for steering, you may be able to use the left-right axis to provide different drive speeds to two motors. Otherwise, it might be used to drive a power steering servo motor.

If you provide the details of your build (proposed or actual), I might be able to help more.


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## aishah (Jan 7, 2014)

I want to build a cart that can carry books/journals (thick)to use in bookstore. 
The purpose is I want to make easy to move the book from a level to another level(ramp) of bookstore. 
This book cart can control by button/joystick. I already search some info but still cannot to build it.
My problems are I dont know anything about mechanics,motor,power and related to this.
What kind of motor I should use? What type of wheel and its dimension? How about the installation? It is using gear/bearing? 
What calculation I should care(when climb up ramp)? I only have a initial picture of book cart and the project picture?
Here I attached a picture, that someone drawn it for me. Can you give me an idea how to start this project.

Plan:







[/url]

Initial:

Ramp:


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## PStechPaul (May 1, 2012)

It might be possible to use the mobility scooter system for your purposes, but it would be better for you to start your own thread for your build. A joystick might be a good way to control it, and it could be used to provide thrust to assist going up the ramp as well as braking when going down. To figure out the torque and power you need, there are some simple calculations you may use, and although they are designed for vehicles such as cars, they also apply to something like this. I made an on-line calculator that may help:
http://enginuitysystems.com/EVCalculator.htm

If you need help, or have other questions, please start a thread for the purpose. Good luck!


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## aishah (Jan 7, 2014)

Thanks for the reply and link of calculator. Actually I am not familiar with this expression/equation. It is another way, without using this? Mechanically structure maybe. From my initial cart, where can I calculate torque and speed ?

I have created a new thread.http://www.diyelectriccar.com/forums/showthread.php?p=375384#post375384

really appreciated for your suggestion/helps.


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