GoldenMotor.com Forum
General Category => General Discussions => Topic started by: Yoma on October 18, 2010, 03:57:29 PM
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Hi,
I just joined the forum so my apologises if I've meant to give a formal introduction.
Any way, I've been trying to explore sources for a possible idea I had to convert my mobility device, called a knee walker http://www.phc-online.com/Knee_Walker_p/neebop-785.htm (http://www.phc-online.com/Knee_Walker_p/neebop-785.htm) , into low powered electrically assisted one that I could use ( I guess like a pedelec ) so that I had the option of freewheeling it , or using the motor to help on rougher terrain / hills.
The wheel itself roughly 7.5 " in diameter just so you an idea , but there is no axle I can see - rather the bolt that just holds the wheel in , which you can see in the pics below.
http://www.flickr.com/photos/28633046@N02/
Someone suggested I could adapt the 6" inch direct drive using plate / bracket.
If any one has any ideas or suggestions about that then , or any other way I could possibly motorise this wee mobility aid ( I might be on it the rest of my life ) id really appreciate it.
thanks.
yoma
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Hi Yoma and(https://i.imgur.com/evDSMvT.png)to the forum.
You certainly do have an unusual request, but unfortunately I'm not so sure that a simple solution exists.
Most of the smaller wheelmotors contain built in gears to increase the torque from the motor, including the 6" motor you have already mentioned:
(http://goldenmotor.com/hubmotors/hubmotor-imgs/HUB24T6inch.gif)
I'm assuming these motors are intended primarily for wheelchair use and are probably designed to drive in either direction, and therefore would not have the ability to freewheel. Without some form of freewheel, it would be very difficult to use the walker manually without power.
However, GM do sell a mini geared brushless hub motor which does contain an internal freewheel device. Although it is designed to be built into a larger wheel, it might be possible to get a small diameter tyre to fit directly to this hub:
(http://goldenmotor.com/hubmotors/hubmotor-imgs/Mini-Front-Motor-sml.jpg) (http://goldenmotor.com/SMF/index.php?action=dlattach;topic=2634.0;attach=3559;image) (http://goldenmotor.com/SMF/index.php?action=dlattach;topic=2634.0;attach=3559;image) (http://goldenmotor.com/SMF/index.php?action=dlattach;topic=2634.0;attach=3561;image) (http://goldenmotor.com/SMF/index.php?action=dlattach;topic=2634.0;attach=3561;image)
Looking at the 3D Solidworks drawings, I estimate this hub to have a flange diameter of approx 135mm, and the area between the flanges appears to be about 47mm wide and 114mm diameter.
It might just be possible to stretch a single 7x1 3/4" solid tyre (http://greentyre.co.uk/w7inch.html), or even squeeze two 4 x 1" solid tyres (http://greentyre.co.uk/w4inch.html) side by side directly onto the hub, but that's just a wild guess.
Provided that a tyre (or tyres) can be made to fit the minihub, fitting the hub to the walker instead of the two rear wheels should be possible, but unfortunately it will not be straightforward, as some form of mechanical brake will still need to be fitted, along with a battery, speed controller, wiring and a throttle.
If you do not have the skills and facilities to fabricate the required fittings yourself, then you would obviously need to find someone who is both prepared and capable of doing the work for you, but it probably won't be cheap.
I hope you find this information useful, and I wish you luck with your conversion, and if you are able to to adapt it, I would love to see some pictures of the completed conversion.
Alan
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Hi Alan,
I just sent 2 email last night to golden motors ( both in the US / Asia where they sell the kits ) so I will see what happens .
I just assumed the the guy in the uk ( who also deals with Alien ) would be less likely to know as he doesnt sell the kits .
Im assuming there must be some size of wheel that fit on these minihub motors i.e. what size of wheel are they used for normally ?
If gm don't respond ( has anyone ever had a response / why bother having an email ?? ) then maybe there are other mini hub motors by other manufacturers who do.
Thanks any way , for all that helpful information .
yoma
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Yoma,
I'm not sure what the smallest rim size is that can be fitted to the minihub, they are normally used for 20 to 28" wheels, but I would assume 16" should be possible, although 16" is still much too large for your intended use.
I suggest you email Vincent Ross (sales@davincimobility.co.uk) or if you're in the UK, give him a call on 01515 481999.
Da Vinci Mobility are GM dealers who specialise in custom built wheelchairs and they may be able to offer some useful advice or suggest a better solution for your particular needs.
Da Vinci Mobility
6-8 Carraway Road
Gillmoss industrial estate, Liverpool
L11 0EE
UNITED KINGDOM
Tel: +44 1515481999
Fax: +44 1515480333
www.davincimobility.co.uk
Let us know how you get on.
Alan
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Yoma,
I'm not sure what the smallest rim size is that can be fitted to the minihub, they are normally used for 20 to 28" wheels, but I would assume 16" should be possible, although 16" is still much too large for your intended use.
I suggest you email Vincent Ross (sales@davincimobility.co.uk) or if you're in the UK, give him a call on 01515 481999.
Da Vinci Mobility are GM dealers who specialise in custom built wheelchairs and they may be able to offer some useful advice or suggest a better solution for your particular needs.
Da Vinci Mobility
6-8 Carraway Road
Gillmoss industrial estate, Liverpool
L11 0EE
UNITED KINGDOM
Tel: +44 1515481999
Fax: +44 1515480333
www.davincimobility.co.uk
Let us know how you get on.
Alan
Hi,
I recollect that name form somewhere , no doubt while looking for solutions when stuck on my mobility scooter.
Perhaps, as you say, he can give me some other ideas , as Gm motors have not , and probably wont, reply .
thanks once again,
yoma
PS. Have you ever heard of the following company ?
http://www.elebike.com.tw/pro.htm (http://www.elebike.com.tw/pro.htm)
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Yoma,
I'm not sure what the smallest rim size is that can be fitted to the minihub, they are normally used for 20 to 28" wheels, but I would assume 16" should be possible, although 16" is still much too large for your intended use.
I suggest you email Vincent Ross (sales@davincimobility.co.uk) or if you're in the UK, give him a call on 01515 481999.
Da Vinci Mobility are GM dealers who specialise in custom built wheelchairs and they may be able to offer some useful advice or suggest a better solution for your particular needs.
Da Vinci Mobility
6-8 Carraway Road
Gillmoss industrial estate, Liverpool
L11 0EE
UNITED KINGDOM
Tel: +44 1515481999
Fax: +44 1515480333
www.davincimobility.co.uk
Let us know how you get on.
Alan
Dave ,
I took some measurements and the bore on my current wheels are smaller than I thought ( 7mm ) as opposed to the 8 at greentyres .
What I was going to ask then , was whether you think something like a hub ring would be ok to offset this difference if I was to use the mini hub motor i.e. because from what I see of videos of it , it seems to wobble a lot .
Im not sure about the bearings either in this wheel i.e. whether thier hybrid plain shield etc etc which Im guessing will be important too If I do stick a motor on there .
thanks
yoma
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Do you mind me asking what sort of bore size this fits ?
I cant see any reference anywhere and cant seem to get working version of edrawing to see, and of course Gm wont reply :'(
thanks
yoma
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Do you mind me asking what sort of bore size this fits ?
I cant see any reference anywhere and cant seem to get working version of edrawing to see, and of course Gm wont reply :'(
thanks
yoma
What measurments are you looking for. I have rimmed mini motors in various sizes here and can measure what you like. By bore size do you mean the axle thickness?
Sorry I'm not technical person, but I like to help if I can.
Gary
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Do you mind me asking what sort of bore size this fits ?
I cant see any reference anywhere and cant seem to get working version of edrawing to see, and of course Gm wont reply :'(
thanks
yoma
What measurments are you looking for. I have rimmed mini motors in various sizes here and can measure what you like. By bore size do you mean the axle thickness?
Sorry I'm not technical person, but I like to help if I can.
Gary
Hey Gary,
Yes, I mean axle thickness or diameter ( basically how wide the centeral hole of the wheel / hub is )
You can see my bearing if you go below
http://www.mcmaster.com/#ball-and-roller-bearings/=9i3dx1 (http://www.mcmaster.com/#ball-and-roller-bearings/=9i3dx1)
and do a search for part no 5972K286
the inside diameter or bore is 10 mm
outside diamteter is 22
and the width 6 mm
I basically need to know then if the diameter of the axel for the mini hun motor will fit 10 mm
but anything else too like the length of the axle would be useful too.
thanks
yoma
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Hi Yoma
I am away visiting relatives for a few days. I will try to get back to you by monday with those measurments.
Gary
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Hi Yoma
I am away visiting relatives for a few days. I will try to get back to you by monday with those measurments.
Gary
Thank Gary,
Just whenever you get the chance .
yoma
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Yes, I mean axle thickness or diameter ( basically how wide the centeral hole of the wheel / hub is )
I basically need to know then if the diameter of the axel for the mini hun motor will fit 10 mm
but anything else too like the length of the axle would be useful too.
Yoma, the minimotors do not have a bolt going through a hole in the centre like your existing wheels, instead they have a fixed axle which must be securely attached at each end to transmit the torque from the motor (see the attachments below for more details of the front minimotor).
The axles on these motors have a 14mm thread with 10mm flats machined into it.
Alan
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Yes, i mean axle thickness or diameter ( basically how wide the centeral hole of the wheel / hub is )
I basically need to know then if the diameter of the axel for the mini hun motor will fit 10 mm
but anything else too like the length of the axle would be useful too.
Yoma, the minimotors do not have a bolt going through a hole in the centre like your existing wheels, instead they have a fixed axle which must be securely attached at each end to transmit the torque from the motor (see the attachments below for more details of the front minimotor).
The axles on these motors have a 14mm thread with 10mm flats machined into it.
Alan
Alan,
What about just screwing the whole hub motor in with the axel then , or is this just a stupid / bad idea ?
yoma
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Only attaching the motor by just one end of the axle would not be a good idea as it would exert considerable bending forces upon the hollow end of the axle where the wires pass through. I would definitely not recommend mounting it like that, as it is just asking for trouble.
Alan
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Only attaching the motor by just one end of the axle would not be a good idea as it would exert considerable bending forces upon the hollow end of the axle where the wires pass through. I would definitely not recommend mounting it like that, as it is just asking for trouble.
Alan
What about having another hun on the other side , and possibly finding an option that would lessen the power output then ?
I asked about the Bafang Fun motor and got told similiar sort of negtive things, which makes sense but the problem is there is no axle thread that runs from each side - unless I could create one smaller than the the 10mm to pass through the fitting thats enclose in there ( perhaps not a good idea either) or just cut open the area with pipe cutter .
The problem with that idea is the rear had no space in the middle thank to the 2 crossbars that meet
i.e. im lucky if theres eve an inch there .
The front has maybe 3- 3.5 " at glance of clearance - but somehow that would not look right / perhaps draw attention to myself which would not be good i.e. I want this to look a legit mobility device not some crazy mod .
I think there are some other knee walkers thats have clearance at that back / middle where I could stick a motor , though I would still need to somehow cut in there and possibly removed that screw fitting ( not sure the technical name ) thats bit like one of those screw- in light bulbs .
Its pity there wasnt cheaper , less powered option to just fit on the wheels , as Bafang and Gm certainly don't offer it.
:(
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Yoma,
Two mini hubmotors (one sticking out of either side of your rear wheel axle mountings) would make the knee walker very wide at the rear, and you would also require additional wiring and the mounting of a second speed controller as well. As the hubs would need to be fitted facing the same way for the internal freewheel to work, it would mean that one of the axles would have the wires coming out of its outer end (the unsupported end) , where it would be very vulnerable to being snagged and damaged.
I really don't think that using two mini hubmotors would be a very good idea.
As I've already mentioned, this is not a straightforward conversion, and if you can't find someone who is able to carry out the required design and fabrication work, then perhaps you should concentrate on looking elsewhere to see what other options may be available to you to suit your exact requirements.
I'm really sorry I can't provide a more positive response, but in reality, solutions to problems like this are rarely as simple as you might think.
Alan
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Hi Yoma,
I got exactly the same problem as you do. Can't find hub motors (etc) for my walker that actually fits or is as wide as I'd hope. I know this post haven't been updated for a while, but have you gotten anywhere? I'm very interested in knowing if you have found a solution or not, it would save me a lot of time :)
Richard.
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Hi Yoma,
I got exactly the same problem as you do. Can't find hub motors (etc) for my walker that actually fits or is as wide as I'd hope. I know this post haven't been updated for a while, but have you gotten anywhere? I'm very interested in knowing if you have found a solution or not, it would save me a lot of time :)
Richard.
Hi richard,
Its been very slow ( partly due to detrioration in health that has left me housebound for 6 months ) but I have some possibilties now and little more of understanding of what options exist thanks mainly to others help at the endless sphere forum.
i just managed to find a large sprocket I can hopefully use thats already mounted ideally for the gearing I need , if it fits the thread insert as I hope then its just matter of buying the other parts and tools I need .
So basically DC brushed motor using 8 mm chain geared for high torque low speed inc freewheel for manual.
The biggest problem im having is finding shoulder bolts / axle to fit so far to extend the sprocket from the wheel , im not sure if the bolt is metric or imperial ( im assuming imperial )
How are things with you ?
Yoma
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Yoma,
Two mini hubmotors (one sticking out of either side of your rear wheel axle mountings) would make the knee walker very wide at the rear, and you would also require additional wiring and the mounting of a second speed controller as well. As the hubs would need to be fitted facing the same way for the internal freewheel to work, it would mean that one of the axles would have the wires coming out of its outer end (the unsupported end) , where it would be very vulnerable to being snagged and damaged.
I really don't think that using two mini hubmotors would be a very good idea.
As I've already mentioned, this is not a straightforward conversion, and if you can't find someone who is able to carry out the required design and fabrication work, then perhaps you should concentrate on looking elsewhere to see what other options may be available to you to suit your exact requirements.
I'm really sorry I can't provide a more positive response, but in reality, solutions to problems like this are rarely as simple as you might think.
Alan
Hi Alan,
I agree not simple , perhaps you could use that hub in trike - like set up with the same sort of idea below ?
http://www.zapworld.com/electric-vehicles/electric-scooters/zappy-3-ez (http://www.zapworld.com/electric-vehicles/electric-scooters/zappy-3-ez)
BTW Does any one know what the pich thread size on the 24 v Model: MBG36R -- Mini Rear hub is and whether its metric or not ?
thanks
yoma
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BTW Does any one know what the pich thread size on the 24 v Model: MBG36R -- Mini Rear hub is and whether its metric or not ?
Yoma, the axle thread is metric, and it should be M14 x 1.5 if my memory is correct.
Alan
P.S. The attached picture was in response to your question (now removed) regarding the axle on the PW-12H wheelchair motor.
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Thanks Alan,
I don't think hubs are great idea any way with the motor being on the wheels , in fact theres only 1 set of hubs there I believe that might fit I saw but their almost 10 lbs combines .
Really id need to be more down around the 6lb weight like with the 2 previous ones I thought might fit last year, but if worst comes to worst I still might still try hubs as option - if I increase the wheel size to compensate for the sort of drag Id imagine theyd cause might not be so bad.
yoma
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Yoma,
Two mini hubmotors (one sticking out of either side of your rear wheel axle mountings) would make the knee walker very wide at the rear, and you would also require additional wiring and the mounting of a second speed controller as well. As the hubs would need to be fitted facing the same way for the internal freewheel to work, it would mean that one of the axles would have the wires coming out of its outer end (the unsupported end) , where it would be very vulnerable to being snagged and damaged.
I really don't think that using two mini hubmotors would be a very good idea.
As I've already mentioned, this is not a straightforward conversion, and if you can't find someone who is able to carry out the required design and fabrication work, then perhaps you should concentrate on looking elsewhere to see what other options may be available to you to suit your exact requirements.
I'm really sorry I can't provide a more positive response, but in reality, solutions to problems like this are rarely as simple as you might think.
Alan
Alan , what about the hubs that don't have the wire coming out of the side , like the bottom 8" one on the right ( Model: HUB24S ) , or is this a common problem with all small hub motors , at least gm ones ?
thanks
yoma
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Alan , what about the hubs that don't have the wire coming out of the side , like the bottom 8" one on the right ( Model: HUB24S ) , or is this a common problem with all small hub motors , at least gm ones ?
Yoma, I don't know the weight of the HUB24S so it's difficult to say how much heavier it is likely to be, but at least it should be possible to adapt your kneeler with some cutting and welding as I've tried to illustrate in the attachment below. You would need to find someone who could turn up some steel adapters on a lathe which could then be welded in the required position. A 20mm rod put through both adapters during the welding process should ensure they end up correctly aligned with each other.
It might be easier to drill and tap the adapters to allow a couple of grub screws with conical ends to tighten into the key slot on the axle to prevent the axle from turning, as I imagine that machining the key slot into the adapters could be a lot more hassle.
As the HUB24S is a brushed motor, you should be able to run both motors from a single controller by simply wiring them in parallel, but I still feel that the device would be much easier to use with a free-wheeling action, but I don't think this is an option with the HUB24S geared motors.
I'm not sure how far off my scaling is, but I'm hoping it's somewhere near, but at least it should give you something to think about.
Alan
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Yoma, I don't know the weight of the HUB24S so it's difficult to say how much heavier it is likely to be, but at least it should be possible to adapt your kneeler with some cutting and welding as I've tried to illustrate in the attachment below. You would need to find someone who could turn up some steel adapters on a lathe which could then be welded in the required position. A 20mm rod put through both adapters during the welding process should ensure they end up correctly aligned with each other.
It might be easier to drill and tap the adapters to allow a couple of grub screws with conical ends to tighten into the key slot on the axle to prevent the axle from turning, as I imagine that machining the key slot into the adapters could be a lot more hassle.
As the HUB24S is a brushed motor, you should be able to run both motors from a single controller by simply wiring them in parallel, but I still feel that the device would be much easier to use with a free-wheeling action, but I don't think this is an option with the HUB24S geared motors.
I'm not sure how far off my scaling is, but I'm hoping it's somewhere near, but at least it should give you something to think about.
Hi Alan,
I think if these wheels don't freewheel then it would defintely be a problem , its pity gm didnt do something like the e-motion hubs seen here, as those would ideally for keeping in sync with when I do or don't need to step and my slow pace.
http://www.youtube.com/watch?v=SGPMELUicG4 (http://www.youtube.com/watch?v=SGPMELUicG4)
The other thing that bothes me about freewheeling with mobility motor ( I know most scooters have this option so you can move / push ) is the motor resistance .
i know on some scooters I looked into for motors like the travelscoot http://www.youtube.com/watch?v=1niBrn9F7HY (http://www.youtube.com/watch?v=1niBrn9F7HY) you can freewheel without the motor ( as somone told me , they've done it )
but im not sure if that has culminative effect over time, or whether it just something company themselves say to prevent any liability issues from people attempting to use it for other means.
When I asked that manufacturer of travelscoot motors in Korea to clarify that , they didnt really seem to understand as their English was not so great .
Perhaps If there was one of those ebay going cheap id buy just to try any way, but unfortunatley theset things cost 2 grand, and the e-motion is double :(
On a positive note I have finally been able to find axle / bolt that fits my kneewalker ( m10 socket capscrew ) which at least gives me more options for the wheels.
thanks again,
yoma
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The Cute Q85 250W hub motor weights only 1.72 kg, has a built-in helical gear for low noise and is only 83mm wide. It has a freewheel mechanism that is very easy to change direction on, only screw it apart and assemble the wedge disc the other way. if you use a single motor controller for both motors then they will rotate synchronously (use the hall sensors from the wheel least likely to spin).
I am currently designing a modification to this motor to allow to fix the motor single sided but this mod is easy and use only one new part which is easy to install and to replace if you want to go back to original motor.
Send me an PM if you are interested in such a solution.