Help with understanding power chair/mobility scooter motor installation

Thread Starter

Mr Tel-Boy

Joined Jul 31, 2020
10
The title should have read
Help with understanding power chair/mobility scooter MOTOR installation

Good after noon, or morning depending on when you are reading this. As I have said in my previous post I am a complete novice so the Technical information written in engineering terms goes way over my head and is way over my pay grade! I have two 24v motors from a power chair, I have 2 12v batteries from a mobility scooter and nothing else, if it is possible the next project will be built around these parts (if it'd not doable, I'll have to seek out another mobility scooter, it just seems such a waste not to use these parts). What I need to know is, how do turn my 2 batteries and two moters into something that start gradually and stops as in a break. Please be gentle with me cos when you guys start getting into Ohms Impedance, diodes and resisters and the hieroglyphics that is the math my brain starts to hurt!

Many thanks

Tel-Boy
 

MrChips

Joined Oct 2, 2009
22,067
You have a motor and a battery.
Usually, there is a motor speed controller that goes in between the battery and the motor.
You need to get a hold of that controller.
The knob/twister/wig-wag that goes on the handlebar sends a signal to the controller. Hence the controller is the essential part of the system.
 

Thread Starter

Mr Tel-Boy

Joined Jul 31, 2020
10
You have a motor and a battery.
Usually, there is a motor speed controller that goes in between the battery and the motor.
You need to get a hold of that controller.
The knob/twister/wig-wag that goes on the handlebar sends a signal to the controller. Hence the controller is the essential part of the system.
Ah, I see, I was a bit miffed because the mobility scooters seem to have a great big box of electronics under the seat, so this sounds encouraging, I want to try to build a small TUKTUK!

Thank You
 

MisterBill2

Joined Jan 23, 2018
7,234
The first concern is that medical grade mobility scooters in the US have all sorts of safety standards, far beyond what is reasonable. The safety standards are intended to save drunks bent on self destruction, and usually triple the cost and complexity of any controls system. THAT is one of the reasons for that very big box of electronics under the seat.
 

Alec_t

Joined Sep 17, 2013
11,730
Whichever country you're in, it's likely you'll have to comply with various regulations if you intend to use the tuktuk on public roads. Have you checked with you insurer that they would cover a home-built tuktuk?
 

MisterBill2

Joined Jan 23, 2018
7,234
Consider that any sort of vehicle built will need to have controls to provide both speed and steering controls, in addition to a suitable mechanical structure to keep it all together and support a rider, the goal stated in post #1 is very ambitious.
So my suggestion is to seek out a suitable vehicle that only requires the parts that you have. Creating a safe vehicle is not a simple task.
AND, I do not know what sort of thing a "tuktuk" is, can the TS provide an explanation of that?
 

Irving

Joined Jan 30, 2016
1,056
Wheelchairs have 2 motors to facilitate steering, a tuktuk is more like a mobility scooter that has a single motor on a transaxle driving both rear wheels. The control system for a wheelchair, using a joystick, blends forward/reverse and left/right commands into left and right hand motor direction/speed demands. That for a mobility scooter simply provides direct direction/speed control for the single motor.

So a wheelchair control system is totally unsuited to a tuktuk arrangement.

If you want to know more about wheelchair controls, particularly the PGDT R-Net system, which is arguably the best available, just ask.
 

Thread Starter

Mr Tel-Boy

Joined Jul 31, 2020
10
Whichever country you're in, it's likely you'll have to comply with various regulations if you intend to use the tuktuk on public roads. Have you checked with you insurer that they would cover a home-built tuktuk?
This project will be used only on private roads and fields.
 

Thread Starter

Mr Tel-Boy

Joined Jul 31, 2020
10
Wheelchairs have 2 motors to facilitate steering, a tuktuk is more like a mobility scooter that has a single motor on a transaxle driving both rear wheels. The control system for a wheelchair, using a joystick, blends forward/reverse and left/right commands into left and right hand motor direction/speed demands. That for a mobility scooter simply provides direct direction/speed control for the single motor.

So a wheelchair control system is totally unsuited to a tuktuk arrangement.

If you want to know more about wheelchair controls, particularly the PGDT R-Net system, which is arguably the best available, just ask.
Thank You Irving, fortunately, where I live is like the Mobility Scooter Capitol of the UK, there are always Cheap mobility scooters available as people either upgrade or unfortunately damage their scooters, the last project was from a damaged scooter and the next one, now looks increasingly likely to be built from another damaged scooter. There is a lady round the corner who unfortunately damaged her scooter on some railings recently and is planning to buy a new one, i will speak to her daughter and offer to buy the old one.
 

MisterBill2

Joined Jan 23, 2018
7,234
This is a Modern TUKTUK
View attachment 216039
OK, now that I understand what it is, I can offer a bit of advice. The tuktuk is a lot more size and weight than a mobility scooter, and that means that it takes more power to drive it. That also means that the single motor in a tuktuk probably delivers more power than the both motors in the mobility scooter.
One option might be to use both motors, one for each wheel, instead of an axle system. But still, anything close to an efficient speed control system is not a simple thing to build and make work. The speed control from the mobility scooter would be adequate for use with that size of motors and batteries, but the performance would be less than other similar vehicles.
So would this be a general transportation vehicle? Or some other use?
 

Irving

Joined Jan 30, 2016
1,056
A typical power wheelchair weighs 60 - 90kg + 1 user, the motors can be as weedy as 10Nm torque @ 110rpm (4mph) = 0.15HP, or 30Nm torque @ 170rpm (6mph) = 0.7HP. A tuktuk weighs 3 - 4 times that plus passengers and would be typically fitted with a 50cc or 100cc bike engine giving 15 - 25HP.

Personally, I think you're going to be severely disappointed except as as a child's toy. And even if you could build something with those motors without them burning out (or just simply not moving as the controller folds back on current limit), your battery life is going to be measured in minutes rather than hours...

If you want to build an electric tuktuk, start with a golf-buggy transaxle and controller....
 

Thread Starter

Mr Tel-Boy

Joined Jul 31, 2020
10
Perhaps I should explain what I would like to do a little more clearly. I would like to build a 'small version' of something that looks like a TukTuk, it will only seat one (the operator), if I use a Mobility scooter as the chasis and the 'engine' I will, as i did with my last project, keep it so it conforms to the UK requirements for a class 3 Mobility Scooter, lights, indicators, horn, reflectors, mirrors breaks etc. I will use something light weight, aluminium or UPVC to form the body panels and will alter controls and steering as necessary. The initial question was put out there so as I could understand if it was within my reach to use the motors that I had. It seems that it's probably going to simplify things greatly just to get another mobility scooter and go from there. I am extremely grateful to everyone who has commented on this, many heads make light work!
 

MisterBill2

Joined Jan 23, 2018
7,234
Perhaps I should explain what I would like to do a little more clearly. I would like to build a 'small version' of something that looks like a TukTuk, it will only seat one (the operator), if I use a Mobility scooter as the chasis and the 'engine' I will, as i did with my last project, keep it so it conforms to the UK requirements for a class 3 Mobility Scooter, lights, indicators, horn, reflectors, mirrors breaks etc. I will use something light weight, aluminium or UPVC to form the body panels and will alter controls and steering as necessary. The initial question was put out there so as I could understand if it was within my reach to use the motors that I had. It seems that it's probably going to simplify things greatly just to get another mobility scooter and go from there. I am extremely grateful to everyone who has commented on this, many heads make light work!
What is NOT within your reach is building a speed control, and so you will need to recover one from a mobility scooter. Be sure to get all of the wiring along with the controls, since usually the old scooter has no manual available any more.
 
Last edited:

bassbindevil

Joined Jan 23, 2014
110
There are cheap pwm speed controls for DC motors on ebay in various sizes. I got a
"60A DC 10-50v 12V 24V 48V 3000W DC Motor Speed Control PWM HHO RC Controller" to use with an old Sears trolling motor which pulled about 40 amps from a 12V battery at full power in a water barrel. The board has 8 NCE7190 N-channel MOSFETS, rated 90A, 71V, 6.8 milliohms at 10V. While the board in the pictures says XY-1260, the board I received was marked Xinrui XR-180.
https://www.ebay.com/itm/60A-DC-10-...ed-Control-PWM-HHO-RC-Controller/202992808923
There are other boards that include reversing relays, like:
https://www.ebay.com/itm/DC10V-50V-...PWM-Controller-Reversible-Switch/353166545075
 

MisterBill2

Joined Jan 23, 2018
7,234
That "Cheap PWM speed control" described in post 16 could work but still, the motors of a single mobility device may not be able to deliver enough power to provide satisfactory performance. Converting a mobility scooter into a miniature TukTuk would be an interesting project, and if the original controls can be repackaged so that they still work it should function. But the TS will need to be very careful to record all the details of all the connections so that the present drive system can be made to function.
 
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