I made an electric wheelchair from a scooter

I built it from a 350W 36V KXD scooter. In a wheelchair, I need it to back up!
I tried changing the phases every whichaway and NG
I disconnected the small multiple plug connector to the Halls sensors thinking without rotation info it might reverse: NG

Beyond that, I'd like to have more torque (they call this Schooleys Mountain for a reason ) which implies a 500W motor, bigger controller and bigger battery (it only goes 5mi now), so time to figure out how to remedy all the shortcomings now.

Sorry that I haven't spent more than a few days looking for my answer! I'm a 73 YO paralyzed Volkswagen mechanic, so pretty old school, but I did manage to hack my VW Digifant ECM to find the full throttle fueling tables! And I know when I need help!

Good first DIY system. Don't know whether this helps, but ebikekit has a 500w direct drive motor with reverse. My friend and I built a bike with a sidecar, which would accommodate a wheelchair, with this motor.

I'll need a wheel/hub-motor that I can install in my existing forks. Can you direct me to your source?
Thanks for responding!

Some controllers have reverse, I think getting a more powerful controller with reverse would be a good start.
Your motor can probably handle a lot more power, at least for short periods. I recommend installing a temp sensor in your motor, so you can monitor the temp. The best thing is if your controller have temp control, but otherwise you can have a meter and check yourself.

Put ebikekit in your browser. One individual, who posts regularly here, used to work for them and may contribute. Their motor won't fit into your forks though, but there are others that I've seen that might. Just use your browser for scooter motors.

Very cool. Love the sign.

hi i know i make my 3220 motor if need to in a wheelchair

god has a plan alll i say


all the best :thumb:

G'day there.
That is a clever bit of re-engineering. Very impressive.
If it wasn't for the cool looking "Volvo from hell" shield ( on mobility scooters, it's called a "modesty shield" , isn't that cute? ) It looks like you could just turn the handle bar until it faced backwards for reverse.
For more range, don't overlook good old SLA batteries. The extra weight, mounted low, helps stability.

AussieRider

pfcs49 said:

Beyond that, I'd like to have more torque (they call this Schooleys Mountain for a reason ) which implies a 500W motor, bigger controller and bigger battery (it only goes 5mi now), so time to figure out how to remedy all the shortcomings now.

Click to expand...

Nice work on the scooterized wheelchair! With more torque and steeper hills that shift weight to the rear, the front wheel more easily runs out of traction and spins. Some commercial versions of this kind of setup have the option of adding ballast weights because of this. I drive something similar too, and adjusted the rear wheels all the way backwards for better weight distribution (manual handling is worse though). Still, some hills are too steep forwards, but can be climbed in reverse with a capable controller (I use VESC).

It's scary to try to climb a hill forwards but run out of traction before the top and start sliding backwards. Sliding friction is less than static friction. In that case if both arms are useful, one can hold the handlebar and gently give throttle while the other one propels a back wheel or locks the rear brake to save the situation.

Speaking from experience, a wheelchair setup like this is fun and expands the travel range of manual wheelchairs enormously. But it's basically a high-center-of-gravity tricycle with poor stability, and tip-overs happen regularly (5 in 5000 km for me).

Just seeing this! Very great. I don’t think traction is my limiting factor because leaning over the handlebars solve the problem every time even in the rain,But the thing runs so slow like it’s about to fall down. I doubled up on the batteries and it went from 3 to 4 miles an hour but it’s still flat, need more torque

You might want to check out Golden motor. They make all kinds of hub motors including small ones (8", 12") with tires.
Scroll down the page and you'll find lots of options. https://www.goldenmotor.com/

Hobby king has good prices on lithium batteries (more volts you go faster, More amps you climb steeper hills).

Read up on lithium before using them. Neptronix has a good sticky thread in the battery section here.

Good luck. Love what you did making your scooter. :thumb:

pfcs49 said:

Just seeing this! Very great. I don’t think traction is my limiting factor because leaning over the handlebars solve the problem every time even in the rain,But the thing runs so slow like it’s about to fall down. I doubled up on the batteries and it went from 3 to 4 miles an hour but it’s still flat, need more torque

Click to expand...

Your current motor is a direct drive motor it seems so you should get a geared motor laced in a (very) small wheel/rim. A Q128 in a 12" or 14" rim would do the trick:https://bmsbattery.com/motor/397-15...v-brake-hub-motor-ebike-kit.html#/213-rpm-201

Much time spent and some progress made. At least I'mmuch more familiar with what I have and what I want.
For the short term, I have 4 controllers that reverse, two 36V and two 48V (plus the original that doesn't reverse)
It seems that this humble $155 scooter has some sophisticated genes! It had digital communication (TXD and RXD busses) and variable braking control signal (analog).
The 4 reversing/cheap chinese motor controllers don't seem to have any of that! Although I can connect my 6 wire multi-function display & throttle so the throttle works and voltage is displayed, there is no speed, distance, or RPM function which sucks and is not satisfactory.

I am not understanding some of the functions or lack thereof, in the chinese aftermarket controllers.
Don't understand how the H Brake and L Brake circuits work except that if I ground the L Brake wire, it applies the brake. H Brake doesn't respond to power or ground. The control on the KXD scooter outputs a 0.77V-3.5V signal via a 3 wire JST plug.
The [/img][/img]"three speed" plug on chinese analog controller: 3 wire, one is ground. Grounding one side lowers the speed limit; the other does nothing I can see.

As far as I can see, there's no way to get this controller communicating with my MFD (multi-function display). Someone previously posted a link to eBay sale of one that looks like mine. It has the 6 wire MFD/throttle (B+, ign, grnd, throttle sig, RXD,
TXD) and the display looks like mine, but all his controllers are only 250W. And I searched! And no reverse.

So help me if you can: brakes implementation, workaround or controller w/reverse that supports my MFD, or MFD that works w/chinese simple controllers AND has most of my functions (voltage, "fuel gauge" bars, speed, odometer, elapsed time, etc). It also has 3 speeds!

Is there a tutorial I missed ??

j bjork said:

Some controllers have reverse, I think getting a more powerful controller with reverse would be a good start.
Your motor can probably handle a lot more power, at least for short periods. I recommend installing a temp sensor in your motor, so you can monitor the temp. The best thing is if your controller have temp control, but otherwise you can have a meter and check yourself.

Click to expand...

I have that covered now: 48V 500W controller w/Reverse, and 10Ah/48V battery. I can install NTC sensor and monitor temp.
But the MFD wants digital data stream and all the chinese aftermarket (4 I have so far!) motor controllers have no data busses.

My questions/issues now: any cheap, reversing controllers that will communicate with my MFD?
How is braking implemented? The KDX scooter uses a 3 wire 90* thumb control which outputs 0.77V to 3.5V signal from it's 5V supply.
Aftermarket controllers have H Brake and l Brake (High & Low??) lines.

Since I'm making multiple "wheel-scooter" attachments, I'd like to re-use the existing MFD/throttles and brake controls. The original MFD is quite handy and nice!!

I'll be building 36V "boulevard" 350W w/8" solid tire and semi-off-road 10" pneumatic/500W wheel-scooters.

ProgramThyself said:

pfcs49 said:

Beyond that, I'd like to have more torque (they call this Schooleys Mountain for a reason ) which implies a 500W motor, bigger controller and bigger battery (it only goes 5mi now), so time to figure out how to remedy all the shortcomings now.

Click to expand...

Nice work on the scooterized wheelchair! With more torque and steeper hills that shift weight to the rear, the front wheel more easily runs out of traction and spins. Some commercial versions of this kind of setup have the option of adding ballast weights because of this. I drive something similar too, and adjusted the rear wheels all the way backwards for better weight distribution (manual handling is worse though). Still, some hills are too steep forwards, but can be climbed in reverse with a capable controller (I use VESC).

It's scary to try to climb a hill forwards but run out of traction before the top and start sliding backwards. Sliding friction is less than static friction. In that case if both arms are useful, one can hold the handlebar and gently give throttle while the other one propels a back wheel or locks the rear brake to save the situation.

Speaking from experience, a wheelchair setup like this is fun and expands the travel range of manual wheelchairs enormously. But it's basically a high-center-of-gravity tricycle with poor stability, and tip-overs happen regularly (5 in 5000 km for me).

Click to expand...

What is VESEC?

Are you wheelchair bound like me?
Not afraid of high CG! I'm often hitting the ground!
I have electric reversing.

The "VOLVOS FROM HELL" decal was from my able-bodied days when I raced Volvos in ITB. Griff and I flat-towed our cars cross-country for 6 weeks in 1990 and camped everywhere, raced every weekend. Truly a transformational experience.
In 95 I rode my 66 250 Mack 1 Ducati into the front of a car at high speed and spent time with Christopher Reeve (Superman) and traded my Volvos for a wheelchair.
In 2002 I built an 88 VW GTI 5spd w/hand controls and raced it quite successfully for 3 years until writing it off big-time at Road Atlanta.
Small wiper motors handled the 5>4 and 4>3 downshifts and VW auto-stick vacuum stuff handled the clutch. It was empowering to be as fast as able-bodied folk again. In fact, I had a bit of an advantage: I could "left foot brake"!

Very cool story!!!

Good for you!

I've never met a racer I didn't like.

pfcs49 » Dec 16 2020 1:51pm
The "VOLVOS FROM HELL" decal was from my able-bodied days when I raced Volvos in ITB. Griff and I flat-towed our cars cross-country for 6 weeks in 1990 and camped everywhere, raced every weekend. Truly a transformational experience.
In 95 I rode my 66 250 Mack 1 Ducati into the front of a car at high speed and spent time with Christopher Reeve (Superman) and traded my Volvos for a wheelchair.
In 2002 I built an 88 VW GTI 5spd w/hand controls and raced it quite successfully for 3 years until writing it off big-time at Road Atlanta.
Small wiper motors handled the 5>4 and 4>3 downshifts and VW auto-stick vacuum stuff handled the clutch. It was empowering to be as fast as able-bodied folk again. In fact, I had a bit of an advantage: I could "left foot brake"!

Click to expand...

Glad to see your still into mobility, quite a few here have disabilities, not to your extant. If it was not for my trike would not get much exercise.

Playing with these machines is half the fun.

pfcs49 said:

But the MFD wants digital data stream and all the chinese aftermarket (4 I have so far!) motor controllers have no data busses.

My questions/issues now: any cheap, reversing controllers that will communicate with my MFD?

Click to expand...

The problem is that there are no real standards for display-controller interaction/communication. In general, but not universally, the same brand of controller and display will work together, even if purchased separately, but there may not be full communication, and the display may not show all the data the controller sends it, and the controller may not accept all the settings the display sends it, etc.

There are some open source softwares (OSFW) for LCDs (displays, MFDs) and controllers that make them compatible and customizable, with various threads here on ES (projects actually on GitHub, IIRC), that may do much of what you want (if you get compatible hardware, as what you have may not be; probalby isn't).

How is braking implemented? The KDX scooter uses a 3 wire 90* thumb control which outputs 0.77V to 3.5V signal from it's 5V supply.
Aftermarket controllers have H Brake and l Brake (High & Low??) lines.

Click to expand...

Hi Brake means you short the brake line to 12v to engage braking--useful when you have 12v lighting and brake lights, so you can just tap off the brake light lever wiring. Lo Brake means you short the brake line to ground for braking.

Whether that braking means actual electric braking (regen) or just disabling the motor depends on the specific controller settings (which are not usually user-accessible, preprogrammed from the factory; sometimes there is a pad on the board inside you can solder a wire to ground from that will enable regen; often there isn't or it doesn't do anything).


If there is no brake lever or signal on the original scooter the MFD/throttle came from, then if it does have electric braking it probably works by rolling off the throttle; instantly dropping off the throttle would likely not engage braking. This is usually called "slip regen", so a controller with that feature would work similarly.


The throttle on the scooter works the same way that all the hall sensor based throttles do, though their rotation range and exact voltage range vary depending on design.


Since none of the controller/display combos do things the way I want them to, I use the Cycle Analyst v3 from Grin Tech http://ebikes.ca to do most of it, though I am still designing some electronics to work around some of the CAv3 limitations for my specific purposes (since while my legs still work, they hurt a lot in many situations, and so I need the motors on the SB Cruiser trike to do pretty much everything for me in very specific ways).

So that might be another option for you, since the CAv3 works for every controller of any type (because it does not communicate with the controller, but instead accepts a bunch of different sensor/control inputs and then simply outputs a throttle signal to the controller to tell it what to do based on those inputs and your settings).

amber wolf: "If there is no brake lever or signal on the original scooter the MFD/throttle came from, then if it does have electric braking it probably works by rolling off the throttle; instantly dropping off the throttle would likely not engage braking. This is usually called "slip regen", so a controller with that feature would work similarly."

Hidden by my left hand, there's a thumb brake with ~90* range of motion. It's a 3 wire deal, probably Halls based, outputting .77-3.5V. Touching it kills the throttle and it (roughly) progressively increases braking with position. It is pretty useless! On a steep pitch it barely maintains speed and in an emergency, forget it! Early on, I fabbed a mechanical brake using a pair of padlock hasps. I STILL can't lock my brakes though :lol: but they're pretty effective. At 15mph it stops in about 12 feet)
Rolling off the gas has no braking component.

Also, remember, this $155 scooter has digital interface from MFD to motor controller. How they can produce these for that price is incredible! Another issue/desire is to retain the original MFD/throttle (throttle signal is analog) assembly because it's there, it's useful, and I don't fancy changing it and possibly the brake controller as well! and end up with less functionality than the cheap scooter provides!!

I need to see if I can adapt this variable brake "switch" to the aftermarket chinese motor controllers which seem to only have Hi & Lo Brake circuit deal.
AND: "What is VESEC?" please

I'm making a bigger better badder scooterchair attachment.

(also revising the original w/reverse and larger steering angle)

The plan is to run a 48V/10Ah battery and a bigger motor, electrically and tire-wise with at least a 10" knobby pneumatic for a little rough riding off-road.

The original KDX is 8" airless/300W nominal motor, 36V

What happens if I run a 60V motor at 48V? And torque is important. The 300W/36V original deal really falls down on hills but still climbs very steep public roads here on Schooleys Mountain.

I should perhaps try a 500W controller first and see what the motor does. Unfortunately no temp sensor but I do have an infra red pyrometer.

Thanks, guys

PS: shopping on the net, seems like doing drugs! Where can I find a straight shooter supplier of scooter motors?

I'll type it again: use a GEARED hub motor in a small wheel!
That way you'll have all the torque you need. And when overvolting it you'll even get enough speed. You can weld or glue the internal clutch so you'll be able to have regen braking and reverse.
A Q128H in a 12" or 14" kids/pitbike rim with knobbly tire will be more than you can handle.

At this point, I don't want to go to such a big wheel. I can easily adapt the mountings for a higher tire and can cut, weld, and bridge the fork for a ten or even twelve inch tire but I'd need to start from scratch otherwise. Based on the performance of the stock "350W" motor, I hunch going to a geared motor won't be necessary.

Generally there's no good empirical info to compare one chinese hub-motor to another. AFAIK, one man's 350W motor may be as torquey as another's 500W!
I'm about to put a 36V/17A controller with reverse, into the chairscooter, but before that I will take it up the nearby hill that slows it to 3-4mph, and monitor current and voltage. I want INFORMATION! (Patrick MacGooen/"The Prisoner") Then I can start problem solving.

The (tiny!) original controller has no current or cutoff specs (but communicates digitally with the MFD-go figure!).
It would be nice to see that it is limiting me at a lower amount than the 17A one. (I also have a rather large, 30A reversing controller. At this point, the motor is expendable; if it won't work for me, it may as well not work at all!) For now, I won't open it to put in a temp sensor but will watch it with an infra-red pyrometer.

I've confirmed that the 17A controller DOES brake (not just shut off motor). The KXD scooter brake control is analog but presents a .77-3.5V signal to the original motor control-box from a 5V supply. I still need to see if running that to either H or L brake circuit gives variable braking but I doubt it.
Once I've explored the brake options and/or installed a brake lever with brake-switch, I'll put in the 17A controller and see where we land.

Congratulations, looks like you're figureing it out.

Not sure what your needs are, but Golden Moter has been around as long as this forum has. They probably sell what you need.

I wouldn't under volt a motor. Don't see the need. More Amps=more chooch.

pfcs49 said:

The KXD scooter brake control is analog but presents a .77-3.5V signal to the original motor control-box from a 5V supply. I still need to see if running that to either H or L brake circuit gives variable braking but I doubt it.

Click to expand...

It won't. Unless the controller is designed with a variable-braking (proportional regen) capability, it can't do it, and unless it specifically states that's what the brake input is for, it's extremely unlikely (never seen it) that it would work that way.

Some controllers (like the Grinfineon present generation) have an on-off brake lever input, *and* respond to a specific throttle input voltage range (like 0.7 to 0.0v) to control the proportional regen braking amount.

Some controllers (like certain Kellys, and other brands) have a completely separate analog input just for braking, which can *also* be used as just on/off with a switch, but would normally be used with a variable-voltage control to give you variable-braking power control.


Another thing that has been attempted a number of times by different people with various on/off-braking-only controllers to try to get variable braking out of them is to PWM the input (switch it on and off *really fast* with electronics) with a varying dutycycle signal...but they are electronically filtered in hardware or firmware or both so that they take so long to respond to the input and to stop responding to the input that this simply doesnt' work.