Advice on hub motors

Hi all,

I am a newbie to this forum but am active on various electric vehicle forums.

I have experience in battery pack building and wiring, having just self installed a 6kwh plug in hybrid kit into my gen2 prius.

I have a disabled child that uses an electric chair, and is only now starting to learn to dive by himself, he is 16 yrs old.

He has just been issued a new power chair by our local authority which is massive, he's only 6 stone in weight but the chair is over 140kg in weight without him sitting in it. It's just too big and heavy to be used practically around the home and when we are out and about shopping and visiting other poeple.

So, with this in mind I had an idea.

I can buy a used manual wheelchair very reasonably priced with the thought of putting 20" or 24" bike wheels onto it.

I can buy an old electric power chair just for the controller and joystick control.

Now, I can mod this myself, I just ned advice on what electic bike hub motors you can recommend that's not going to cost an arm and a leg, the chair only needs to go at 5 mph, the electric wheelchairs generally operate at 24v.

The chaos doesn't need massive range, so no need for big heavy batteries, in fact I already have to hand a lifepo4 lfp26650ev batteries eft over from the prius project, maybe I can someone can suggest an appropriate custom set up for these, they are 10.24 wh each cell, maybe can arrange 2 pr 3 in parallel and 8 in series to get to the 24v target, I have enough batteries to do this, but I have no design experience to see what amps would be required to propel a wheelchair at 5 mph. The cells I have have a 2c continuous rating and a 5c pulse for 30 secs.

Any help and advice on this would be fantastic, as this would give me a pretty light very manoeuvrable wheelchair that would suit most if not all of our needs.

One last point, as I have never come across an ebike before, without any power going to the wheels, are they then still free wheel able to push manually or is there also some internal resistance to push, and how would you attach a brake cable.

Many questions asked here but any advice is greatly aprreciated.

Thank you, anthony.

It seems like you are describing the cheaper versions of mobility scooters.



They don't weigh much, compared to real powerchairs. This is what I generally see people who can still drive using. Often they will have a better one for indoors, but have a "beater" one for taking on the rack behind the car.

Or is there a problem with him operating this type?

Yes he has quadriplegia cerebral palsy ans sits in a special moulded seat, the control method is a fingerpot switch, he's quite severely disabled and a wheelchair is the only option, unfortunately, most manufacturers are making these things bigger and heavier making their manoeuvrability nigh on impossible in places that haven't been adapted for disabled users, even getting his new wheelchair through a standard doorway is now a challenge, no chance at all on the older terrace style uk homes with 27" door frames

He hasn't been able to visit both his grandparents since he's had this new chair as it won't fit through the interior doorways

For your low speed ( < 5mph) , bike hub motors are no going to work well at all.
You need to look for some original drive motors from a power chair which are made to work at low speeds.
There are companies that resell those, or they often come up on ebay.
http://www.ebay.com.au/sch/i.html?_sacat=0&_from=R40&_nkw=wheel+chair+drive+motor&LH_PrefLoc=2&_arm=1&_armm=63&_ruu=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3Dwheel%2Bchair%2Bdrive%2Bmotor%26_arr%3D1
Hopefully there are others on this site more familiar with these units than me who can help.
Come on ES'ers ..put your wasted talents to work on this truly useful project !
http://www.ebay.com.au/itm/Jazzy-Select-Jazzy-Select-GT-Drive-Motor-Assembly-DRVMOTR1281-DRVMOTR1282-/121297090841?pt=LH_DefaultDomain_0&hash=item1c3ddeb919

Straining the memory a bit here but I'm sure I've seen actual wheel chair hub motors - manual chair sized wheels.

Golden motor have had these around for years, not sure if the rpm is correct though. worth a look over.





http://www.goldenmotor.com/

Awesome that he can get a car adapted enough for him to drive with that much handicap. I thought maybe he was a quadruplegic, but might have some better use of his hands if he could drive. I built a house for a guy like that, and he could still use that kind of scoot. He was pretty handicapped, but could use his hands just enough to drive and use handlebars to control a light mobility scooter.

I have often thought that you could make a powered couch using two reversible motors and two joysticks. Skid steering like a bobcat loader or a bulldozer. Each joystick would control one wheel in either forward or reverse. My idea was to use two of the cheap stand up scooters for the motors and wheels, replacing the front wheels with casters.

If he can control the two joysticks with one hand, he could go forward, backward, or spin in one place by running one motor forwards, and the other backwards. Just a matter of mounting it to a chair of some kind, that fits the narrow doorways.

It would be possible to adapt the scooter motors to friction drive motors on the wheelchair wheels. The motors are cheap, and they can run in forward or reverse with some simple switching controlled by the joystick. Reverse polarity to the motor, it runs backwards.

Hi dog man,

When I say drive, I mean drive his wheelchair not a car, unfortunately he's far too disabled to do that, but you never know in the future.....

The link for the hub motors is great, nigh on exactly what I was hoping to get advice on.

There are some neat motors on that site, I would need to do something though,

My reasoning for utilising a standard wheelchair controller ( the powerchair he is used to has a dx control system) is that his fingerpot controller will plug straight into it. He can I only use his pointing finger on his rigt hand to operate anything, as his wrist and elbow movment is not good, but his finger control is very good.

So, if I could get a hub motor either front or rear wheels driven, onto a wheelchair, I would need to control it via a dx wheelchair controller, or find a way to get the pinouts off the fingerpot and try to match then up to the operation pinouts of a standard joystick control.

Thanks for all your replies so far, very helpful, any further help greatly appreciated.

Hi Anthony,

Perhaps you could clarify your aims for this project a little?

It sounds like you want something with the functionality of a conventional electric chair, but built around a lighter manual chair?

The big issue in my mind is the difference in typical wheel size between the two. A motor (hub or geared) intended to drive a small electric chair wheel is going to be unsuited for a manual chair wheel (or 20" bicycle wheel)?

If you are thinking of using bicycle wheels I recall a thread a while ago that described significant problems with mounting bicycle wheels on a stub axle. The context was a proposed trike or recumbent cycle design, I think.

A couple of times I've seen a chap in manual chair with a single hubmotor attached. It's in a trike configuration giving him handlebars for steering and throttle. I don't know if it's a commercial or DIY build and it sounds unsuited to your needs, I just mention it because the motor looks like a typical 9C bicycle hubmotor.

Punx0r said:

It sounds like you want something with the functionality of a conventional electric chair

Click to expand...

hah this could be taken out of context fairly easy

Hi punx0r,

You are spot on, I a minded looking to convert a lightweight manual wheelchair into a low range wheel hub motor electric chair, this for 2 reasons, firstly it's lightweight and highly manoeuvrable, something his new powered chair for sure is NOT.

Secondly, if specified correctly, his fingerpot controller Would be able to be compatible and he can now use this wheelchair to drive it too, in addition to use drive it with a standard attendant control joystick for when the gradient for us to push is too great, and hence the chair becomes too difficult to manage.

I cannot fault our local authority in issuing him a newer chair ( he had grown out of his older power hair) it is a great wheelchair, if everywhere you access has been adapted for disabled access. Unfortunately, our parents houses, somewhere we visit on a weekly basis these older terrace style houses have narrow hallways and tight 90degree bend doorways, also these doors are narrow at 27" (most standard doorways are 30" and all disables access doorways are 33"), as a result we cannot access these homes any longer, and we are having issues with the authority trying to get a powered chair that suits his size and is compact enough to access our daily routines.
That's why I thought of modding a manual chair for our specific needs.
I can get hold of a manual chair that has a tilit in space function quite cheaply, it's ok size wise and is narrow, I was hoping of a method of getting wheel hub motors to fit onto that.
I did see on the golden motors website that they offer in wheel hub motors fitted into wheels from 12" all the way up to a 28" wheel. I would need a 16" wheel with a hub motor incorporated. As I have never come Ito contact with these types of motors not sure if they are free wheeling if no electricity is being supplied, to push easier if done manually, and how to slow down the freewheel if in manual mode like a brake.

I'm sure there are things that can be done, it's a case of gathering the right knowledge of the right kind of people, and on here there are some very clever guys that have done some great things with bikes and the like.

Many thanks for your input and hopefully between us all I will find a solution that would suit our needs perfectly, and something that would last a long time.

Anthony.

Punx0r said:

Hi Anthony,

Perhaps you could clarify your aims for this project a little?

It sounds like you want something with the functionality of a conventional electric chair, but built around a lighter manual chair?

The big issue in my mind is the difference in typical wheel size between the two. A motor (hub or geared) intended to drive a small electric chair wheel is going to be unsuited for a manual chair wheel (or 20" bicycle wheel)?

If you are thinking of using bicycle wheels I recall a thread a while ago that described significant problems with mounting bicycle wheels on a stub axle. The context was a proposed trike or recumbent cycle design, I think.

A couple of times I've seen a chap in manual chair with a single hubmotor attached. It's in a trike configuration giving him handlebars for steering and throttle. I don't know if it's a commercial or DIY build and it sounds unsuited to your needs, I just mention it because the motor looks like a typical 9C bicycle hubmotor.

Click to expand...

Hi,

I'm hoping to try to get advice on a pair of hub motors that can be fitted to a manual wheelchair. My son has a manual wheelchair called an invacare rea azalea, and I'd like to convert it into a lighter power chair so we can use it more easily on holidays and days out where he won't be able to drive himself.

I think the rear wheels are 14" ( like scooter wheel size) and Id be looking for a pair of motors that could generate a speed of only 5 mph max, so power is not the main concern.

I would intend to utilise a controller and joystick of a scrap power hair, the same type of controller and joystick that he currently has on his power chair, this way if we are out and about and he does want to drive he is used to the type of joystick method of movement.

As for batteries, I intend to use either 3 or 4 Nissan Leaf cells, probably 3 to be honest to be around the same 24v as his existing chair.
I have the cells already, I will use cell loggers to mono tor the cells, with a system that I copied on here for a Prius plug in hybrid conversion I carried out a few up years ago.
Please, any advice would be greatly appreciated.

If you haven't done so, check out this thread by Spdas. It may give you some other ideas. PM her as well. I am sure she would be happy to help.
https://endless-sphere.com/forums/viewtopic.php?t=74159

I was looking at the chair you mentioned in your other post, the invacare rea azalea and it looks to me as if driving two motors could be a bit of a problem to work out. Around here most people use two throttles and two controllers on bikes with two motors. Properly set up you could probably use one battery pack, but you would need 2 controllers along with the motors.

Edit: Check out this thread for multi motor setups: https://endless-sphere.com/forums/viewtopic.php?f=2&t=33429

Working a joystick to the system will be a nice trick. The joysticks I have dismantled in the past were essentially multiple potentiometers so I guess getting the right voltages to the controllers/s will be what is necessary.

Have you been able to bench test the joystick to see how it combines or separates output voltages. You will need from just under 1 volt (something like .8v) at stop and something near 5v (something like 4.8v) at full throttle to operate most controllers. So you will need two separates 1v to 5v outputs to operate two controllers to operate two motors. You may also need to bias one of the motors to match the other if they are too dissembler once installed. The controllers will provide the 5v operating voltage that goes into the joysitck, the potentiometers in the joy stick will need to control the output voltages.

Do you have a maker and model and schematic of the joystick you can post?

Are no light-weigh motorized chairs already made?



Edit: this just popped up as well, a dual hub trike thread about dual motor setup: https://endless-sphere.com/forums/viewtopic.php?f=2&t=35209

https://www.alibaba.com/product-det...r_353919633.html?spm=a2700.7724838.0.0.BZrxVC

The same factory offers them in 1 unit MOQ's with CONIS as the brand, so you should be able to get what's needed. These seem to have a gear reduction inside, but for a wheelchair they wouldn't have the freewheeling clutch, which is one of the weak points in geared hubbies. The size tells me the planetary reduction is likely to be beefier than in geared hubbies too, so worth a shot compared to ridiculous pricing of anything available through the medical supply route.