How to program this generic chair from China?

[SweetBearCub]

Hey there folks, long time no post, I hope you're all doing well.

My current work situation requires that I drive a very long commute (about 4 hours one way) into a major city, where I stay for about two weeks out of the month with a friend, essentially couch surfing while I work, then I drive back home. In this major city, I must street park my car, a very small 2017 Chevrolet Bolt EV hatchback, also known as an Opel Ampera E to some international members.

To enable this, I can't bring my 400 pound/180kg Amy Systems Alltrack R3 easily, so I bought the lightest folding power wheelchair I could find on Amazon, 33 pounds/15kg with the 3 pound/1.36kg battery removed. It folds "forward" after undoing one latch, sort of onto itself in a more or less square shape, but fairly thick. An able-bodied person could pull it behind themselves like rolling luggage if needed, to give you an idea.

The Amazon listing was removed (for some unknown reason) when I went back to the site to get some details of it, but it has a 220 pound/100kg weight limit, 360 watt (I'm guessing 2x 180 watt) motors, and has a listed top speed of about 3.73 MPH/6 KPH. Yes, these specifications are pathetic, but it needed to be small and light enough for me to load and unload from the car by myself, and get me around the city to my job sites, which vary. Interestingly, when I unpacked it, I noted that it had no neutral levers on the motors, and driving it confirmed that it was not equipped with electromagnetic brakes. It's nice not to hear a constant loud clacking sound when I stop, but that does require me to be more diligent of course. It has a manual brake lever near each wheel that I can easily reach if needed.

Like most power wheelchairs, I find the default programming to be terrible. When I'm moving forward slowly, it stop and starts, very jerky, it takes seemingly forever to get moving to its maximum forward speed, and small curb ramps in the city, where I have to drive at an angle rather than directly forward slow the chair down a lot. I'd also like to deactivate the reverse beep.

But since this is the very definition of a cheap Chinese thing, it has no real brand name anywhere on it. The controller/brain appears to be fully integrated into the joystick, as under the chair there is only a small removable battery with two leads going to the motors, and no electronics box there, while the joystick is a bit bulbous and oversized, with a thick lead coming off of it. There is no visible programming connector, there is only two XLR connectors, one on the joystick, and one on the battery.

How do I determine what the controller is, so that I can program it to perform more tolerably?

Since my photos of it are too large to upload here directly, I've put them in an album on Google Photos. Here is a link to the photos I took of it.

As a related question, the motors seem to be quite noisy when driving forward, but I have only put less than 100 feet of mileage on it so far. How do I get them to quiet down?

[Burgerman]

Motors on chairs are VERY carefully designed and use special gears and materials to keep them quiet. Thers not likely anything you can do here.

Those controllers built into the joysticks, can be cloned PGstuff VSI lookalike or complee with innards out of the back door... With very rough and ready code that has non of the refinement and cant be programmed with anything we have here. Or can be actual PG controllers and software internally and be programmed with the various mobility programmers we have here. So undo the two mounting allen screws. Look at the label. Brushed or brushless? PG drives or not?

With the drive wheels so far back behind you I dont hold out much hope for any sane steering capability regardless.

[emilevirus]

I have one similar to this. Was undrivable with stock controller. I fitted R-Net. Works so much better now!

[Burgerman]

Looks similar to new VSI that can also do brushless. It could be that, or could have the cloned internals. Or have the actual PG internals and made under licence in which case it CAN be programmed. Look at its label.

[emilevirus]

Most likely a clone if the chair was cheap https://www.aliexpress.com/item/1005008100138558.html

[Burgerman]

This is always a danger when buying cheap chinese stuff.

99% of the cost and work when you buy say a PG Drives joystick is not the plastic case and the circuit boards etc. Its the code. That takes hundreds or thousands of man hours to get as good as the typical powerchair from a mainstream manufacturer is. Even then it will need programming to make it drive well.

I see the same thing across the hobby world. My Transmitter was about 1k pounds. You can get something that ostensibly looks the same, same functions, etc for 10% of that. The problem is that theres a literal london phone book of complex code, with a hell of a lot of options for mixing, and telemetry etc. Anything is possible and its all pretty much perfect. Because a whole comunity, work as testers, and we see hundreds of pages of bug fixes, requests, problem solving and testing in use. I have added new firware to the Recievers, to speed controllers, to transmitters more than 20 times in a year not including hundreds of alfa and beta firmwares and testing.

When you buy a cheap chair with some non brand joystck you get non of that. It can be seriously crap to the point of unusable or dangerous or it could be OK. But no way to tell.

Take a look at the roboteq thread. Thats 90% code, rewrites, bug fixes, etc. And thats super basic in comparison to a Rc system. And about 5% of whats in R-Net.

Theres are 123 full pages or threads. So thousands of posts Just talking about it! Most of the actual work and serious thinking was done by lenny. The chinese are not prepared to spend years, developing and testing and rewriting code. So if it moves back/forwards/turns at all think yourself lucky!

[shirley_hkg]

The Amazon listing was removed (for some unknown reason) when I went back to the site to get some details of it,

Interestingly, when I unpacked it, I noted that it had no neutral levers on the motors, and driving it confirmed that it was not equipped with electromagnetic brakes.

It's simple. They were selling a killing machine.

[SweetBearCub]

Motors on chairs are VERY carefully designed and use special gears and materials to keep them quiet. Thers not likely anything you can do here.

Those controllers built into the joysticks, can be cloned PGstuff VSI lookalike or complee with innards out of the back door... With very rough and ready code that has non of the refinement and cant be programmed with anything we have here. Or can be actual PG controllers and software internally and be programmed with the various mobility programmers we have here. So undo the two mounting allen screws. Look at the label. Brushed or brushless? PG drives or not?

With the drive wheels so far back behind you I dont hold out much hope for any sane steering capability regardless.

I unscrewed the hex screws from the joystick mount and added a shot of the label under the controller to the photo album I posted in the original message.

[JMGarage]

I have same kind chair. It is 36v. It moves straight, but when You try to turn, it slows speed. It almost stops. One positive thing, it was freebie because battery was dead. This frame is coming for testrig.
The frame is more rigid. This is old chair. 10-15 years old.

[shirley_hkg]

I have one similar to this. Was undrivable with stock controller. I fitted R-Net. Works so much better now!

Interested to know how to program Rnet to work without parking brakes connected, and is the chair still holding on incline / slope when you release joystick.

[Burgerman]

Theres is a section that allows its error to be turned off.

So then just remove the brake. I never tried this but thats supposed to work!

On a slope it will roll slowly downhill when you release the joystick. To a degree motor compensation will try and slow it. But it will roll...
If for some reason the power cuts off, fuse, BMS or whatever or if the controller fails, or a user turns it off, it will roll very freely! And get quite fast. Into traffic probably.

[Burgerman]

Above. Not advisable...

Brake is needed or char is not safe. A curb cut for e.g will allow a chair to roll on into the road.

You can balance it on the joystick to hold it still for a while if skilled, but that heats up motors and controller. It will at some point overheat and shut down and you roll down a big slope anyway. But a motor that is stationary with current/torque going through it doesent cool. It needs to spin to stop brushes burning and to cool via airflow inside the case.

I unscrewed the hex screws from the joystick mount and added a shot of the label under the controller to the photo album I posted in the original message

Chineseium. Could be completely garbage. Could be OK ish if programmed but we cant know. And dont have a programmer. And if it doesent have brakes then I would be sending it back to amazon.

[shirley_hkg]

https://youtu.be/RIbNXQ5eHdA?si=FHbRRBBC35tlhtnH


youtu.be/FHbRRBBC35tlhtnH

[Burgerman]

Not working...

[shirley_hkg]

Try the original link.

Guy tried on a slope and switched it off.

[Burgerman]

Says VIDEO REMOVED.

What happens?

[SweetBearCub]

Says VIDEO REMOVED.

What happens?

The video link worked for me. 10 minutes, 46 seconds long. They tested one of those 3 in 1 (rollator walker, power wheelchair, transport chair) devices that turns off its brakes when the power is turned off.

As expected, on a significant hill, it could result in a loss of control. And you're correct, there is a risk there that the control system could overheat or otherwise unexpectedly lose power, and even if not, balancing it at a stop prevents the motors from cooling. I'll (carefully) use mine, since it's my best current option if I want to be able to get to my work sites and I don't have time to get a replacement, but it's critical that any users be fully aware of the limitations and also be capable of stopping them in a hurry with the manual brakes.

Which I did test, and incidentally, the rubber covers on one of the handles was not securely attached. That could be disastrous. I fixed that with some epoxy under the rubber cover.

[shirley_hkg]

Light weight foldable one with stock electromagnetic parking brakes is more or less the same price tags.


Shit happens.


I had an accident 2 weeks ago. I set the brakes too light and didn't know it couldn't hold my chair.
I drove up to top of a slope and stopped to prepare going down by tilting my seat back. It just started to roll down the slope the second that I stopped. It really caught me by surprise to react. Luckily the steel rail fence is just 2 metres away and strong. Or I would run straight down to a 2-storey high rocky sea shore.

[Burgerman]

Thats exactly why that chair from amazon is dangerous!

And why its not a good plan to set that warning and error detection to OFF in the R-Net software. You can. But dont!

[emilevirus]

I like living dangerously!
I just turned off error checking on brakes. It's a chair to go out so there's always someone nearby. I'd never go down a hill with that crap anyway. It's so light that a small bump you flip. It's perfect to go shopping, restaurants, etc. Anything outdoors I use my actual 400lb chair.

[Burgerman]

Info...

These are the VSI and NEW VSI and at least the new one can do some brushess and lithium settings.
Both are tiny and really for indoor type toys or folding chairs.

There are also cloned versions of these with and without actual PG programability. Or at least thats what I am led to believe. Personally I never saw one at all as they are only used on small indoor or portable stuff. Very simple, but very weedy.

[SweetBearCub]

So I tested it out on my last work trip to San Francisco, and although I wasn't sent to any sites that were extremely hilly, it worked well over the course of 3 weeks. The battery, with the watt-hour capacity of 2 of my 20k mAh power banks (pitiful), lasted between 1.25 and 2.2 miles of driving per charge. I'd love to source a bigger battery that can slot right in.

It was within my ability to lift it in and out of my car on my own with some effort.

As a 6 foot tall (1.83 meters) tall US adult male, the seat/footrest geometry was such that I sat too low, making it painful for my knees. Adding a random cushion that I had with me to add some height to the seat helped somewhat.

The motors are still unusually loud. People can easily hear me coming up behind them.

I weigh around 173 pounds. The listed weight capacity of the chair was 220 pounds. Carrying a heavy bag with maybe 15 pounds of cargo was enough to noticeably reduce its capability, though not enough that it couldn't get me to work.

[emilevirus]

The battery, with the watt-hour capacity of 2 of my 20k mAh power banks (pitiful), lasted between 1.25 and 2.2 miles of driving per charge. I'd love to source a bigger battery that can slot right in.

What? Are they 5200mah 25v? Mine lasts about 12 miles.
Looks like they're available here: https://movexmobility.com/product-categ ... arts/mv03/

[Burgerman]

$250 for 10Ah Ah?
$178 for 6Ah?

I can get 244Ah 25.6V for £500 delivered.

Theres an 8.4Ah lithium in my bot!
(£32)

https://www.wheelchairdriver.com/gopro/bot.

[emilevirus]

£250 for how many Ah?

I can get 244Ah for 500 delivered.

I mean... A 2ah Dewalt battery costs more than 230Ah.
Companies make money where they can.. Propertietary batteries but it's just cheap 18650 cells inside, specifically these! They're cheap 2C 2600mah cells. I thought about opening mine and replacing by 3500 Samsung cells. Would give a nice capacity boost for same weight.

[Burgerman]

14 of these 21700 cells, 2P 7S will give you 29.4V full. 10Ah. And cost £36...
Will use the same BMS thats in there already, same charger, etc.
Probably fit same case.

https://www.18650batterystore.com/produ ... 5a-battery

[Burgerman]

18650? Tool? Remember those draw big amps!

https://www.18650batterystore.com/colle ... -batteries

Under 3 dollars each.
In US or UK.

[emilevirus]

Also damn... He's sitting right on top of the batteries. If they blow up it's gonna be a nice barbecue.. Atleast on my chair they're fixed near the rear motors giving me some time to react if they catch fire.