Advice on E- Walker idea ?

General Discussion about electric vehicles.

Re: Advice on E- Walker idea ?

Postby Lock » Thu May 20, 2010 9:03 am

Hello Helena... you don't detail the disability... whether it affects balance or not, whether you can stand for any length of time... but the simpliest "e-walkers" out there are the stand-up scooters with electric assist like the Go-Peds:
http://www.goped.com/Products/
Image

...Some manufacturers offer these with seats. There is a wide range of pricing but ya get watt ya pay for and the Go-Ped line illustrates the more mature and robust end of the design spectrum. Generally you can add baskets etc for cargo/groceries.

Ya might need to check legalities for your `hood, but usually the "D-Word" (disability) means you can get away with almost anything...

So, ya, you might re-invent the wheel (literally) but the little scooters are already "out there", available and performance well understood. One alternative that might be a better option as you can use it for exercise (kicking) more easily if you wish would be the Euro-style foot bikes, of which Kickbike is the most popular example:
http://www.kickbike.com/
Image

...it would not be difficult adding a hub motor kit to the front wheel of one of these.

Cheers
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Re: Advice on E- Walker idea ?

Postby fechter » Thu May 20, 2010 10:33 am

I think it would be pretty hard to modify the knee walker without making it look klugy.

Something like a small scooter with a seat might be close to what you need. You can still push along with your feet if needed. Most of these go pretty fast compared to walking, but you can always control the speed with the throttle. Lower gearing would be helpful too.

This one is no longer made, but there are similar ones out there, and most of them are fairly inexpensive.
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Re: Advice on E- Walker idea ?

Postby Drunkskunk » Thu May 20, 2010 12:07 pm

Anything you attach to that knee board is going to make it look like a mad science project, unless you have the skills to build fiberglass body work to cover it.

What Lock and Fetcher recomend is almost perfectly suited to what you described.

The speed might be an issue. they usualy go 20mph, and crawling slow at a walking speed would heat them up, so a gear change is in order. They are cheap to buy on craigslist, and there are dozens of varities with seats. Buying used may be better since it will need to be modified anyway.


Most come with lead acid batteries. You can change those out for Lithium. But depending on your need, that might be a bad idea. When lead batteries start to die, the power drops off slow, and you have plenty of warning that you need to recharge them. when lithium die, they go from normal power to dead with almost no warning.
when something goes wrong with lead acid batteries, like a dead cell, they often will keep working at a diminished rate, giving you the ability to make it to a safe location. when lithium have even a small problem, they shut off completly. Anoying if you're 10 feet from your door. dangerous if its in the middle of a cross walk on a busy street.
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Re: Advice on E- Walker idea ?

Postby Lock » Mon Oct 11, 2010 9:44 am

How `bout adding a one wheeled trailer where the hub motor is in the trailer wheel so that the trailer is a "pusher"... With battery pack and controller in the base of the trailer only the control wires would need to be lead to the handlebars. Detachable, the overall weight of the vehicle can be split into two for easier handling if needed. The only real mod to the walker would be the hitch added, and either thumb throttle switch added or one handle replaced with a twist throttle grip.

There are electric wheelbarrows out there where parts could be scavenged and reformed:
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Re: Advice on E- Walker idea ?

Postby AussieJester » Mon Oct 11, 2010 9:58 am

I just checked the link in OP for the knee walker, we is in the wrong business checkout what it is and the retail price FAAARK ME!!

And i thought 3k for my wheelchair was ridiculous, which it is, but least it has suspension and a Rock Shox at that :-P

You could easily modify the knee walker i think, i dunno if you have access to workshop tools and your skill level but it
wouldnt be hard to knock up a 3 wheel "knee walker" type affair with a frock (hub) motor on the ass end of it and couple of pram
wheels at the front for steering.

Best of luck anywayz, pity your not local i would definitely give you a hand making something to help you out wouldn't take more than a mornings work to bend up the tubing and weld it all up, bolt on a frock wire it up and you would be ready to enter the 100m sprint :-P

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Re: Advice on E- Walker idea ?

Postby Rassy » Tue Oct 12, 2010 12:53 am

Helena, welcome to the forum. I know you asked about altering the knee kicker, but it looks like it would be difficult to alter without a full rebuild. I.e., those wheels would still be a problem, just like they are without a motor, etc.

I would think that a recumbent trike, delta or tadpole would be a better place to start. With a clipless pedal and shoe you could pedal with one foot. Then you could add a small hub motor with very little modification and you would have a safe ride for your local trails, etc.

Good luck with whatever you decide to do.
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Re: Advice on E- Walker idea ?

Postby dnmun » Tue Oct 12, 2010 11:58 am

maybe a trike like this?

viewtopic.php?f=3&t=22093
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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Tue Oct 12, 2010 2:33 pm

Chekola,

If you think you could manage a folding type bike, then this one might suit: http://cgi.ebay.co.uk/Electric-20-Wheel ... 3cb1905808

I bought one of these a couple of weeks ago and am really quite impressed with it. It has big chunky mountain bike type tyres (nice and wide) full suspension (front and rear) and only needs a battery pack and something to hold it to complete it. There are some pics of mine on this thread: viewtopic.php?f=6&t=21945 (I took all the stickers off mine).

I've no connection to this seller, but can say with confidence that the bike is pretty good value and the sellers service was excellent. I could talk you through the wiring, as I've now done two bikes from the same vendor, the folder and also this conventional ladies bike: viewtopic.php?f=6&t=21960

Unfortunately I'm the other end of the UK from you (although I used to live in Dumfries and Galloway years ago) otherwise I'd be able to offer to help directly.

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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Wed Oct 13, 2010 2:17 am

Happy to help if I can. Those bikes I linked to can be switched to work either with pedelec control or twist grip throttle control, via the switch on the handlebars. They aren't very high powered when run with the controller they come with on 24V, but OK if you don't want to go too fast.

In twist throttle mode they will run quite happily with no pedalling, although pedalling will significantly improve performance and range. The one reservation I would have is that, as standard, they probably won't do really steep hills without a bit of pedal assistance, which may be a problem for you (it depends where you want to go, really).

The rear wheel hub motor that is already fitted to these bikes works well with a standard controller and a higher voltage battery pack I've found. Although designed to run on 24V at 15A, I'm running my folding bike at 36V and 25A and the motor doesn't even get slightly warm, even after a long climb. Fitting a different controller probably means losing the pedelec control option, but if you would prefer twist or thumb throttle operation anyway that isn't really an issue.

Another option is to fit a light hub motor and wheel to the bike you've bought. If you opted for front wheel drive then it would be a fairly simple job to do, perhaps by just fitting a kit. Something like a Cute or Bafang front hub motor, together with a suitable controller and battery pack, and a twist grip or thumb throttle would suit that bike fairly well and should be fairly straightforward to fit (at least, probably not much worse than assembling flat pack furniture..........).

It really comes down to whether or not you can keep your balance OK and feel confident enough out and about on two wheels. There's no doubt that having electric power helps the confidence issue, particularly if there's any traffic about, as knowing the bike will just pull away smoothly without any effort is nice and reassuring.

There's a thread here: viewtopic.php?f=3&t=22093 that might be of interest, too. A trike, although heavier, does have the advantage of stability and, more importantly, the ability to just stop without needing any leg movement to stay upright. Trikes aren't that common, but I believe that Pashley (http://www.pashley.co.uk) still make them for people with special needs (not cheap though!). Fitting a motor to a trike would be no harder, in fact in some ways it might be easier, than fitting one to a bike.

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Re: Advice on E- Walker idea ?

Postby Samba » Wed Oct 13, 2010 7:34 pm

I got my nephew one of these. Image and then his sister used it and now the youngest. A Bike without pedals - they push it and brake it with their feet and learn the balance and steering before they have to mess with pedals and brakes.

If you took something like a BMX bike and took off the chain and crank - you would have essentially the same thing in an adult size? That would take a regular hub motor. If you order a hub in a 20" wheel they may tune it for speed - You'd want one made for a 26" wheel - it will gain 30% more climbing power when put in a 20" wheel - and lower top speed.

When I was a boy - 35 years back - there was a bike called Stingray from Schwinn. 20" bike with high handlebars - quite upright - but also a 'bananna' seat and a 'sissy bar' - that tube going from the back of the seat down to the rear hub.
Image
Some of the 'Sissy Bar's were longer and had a pad on it for use as a backrest. The banana seat was good for foot pushing and if you are sitting back by the sissy bar its actually quite foot-forward and you might even be able to leave the pedals on. Some had a front handbrake, but not all - They made them for girls too so there was a more step-thru frame. They may not make that any more But there seem to be modern clones of it called 'Lowriders' I'm sure a bike shop can get something appropriate. A 24" mountain bike frame might work if fitted with the right seat. I guess it depends how tall you are and what angles are comfortable for your legs and hips.

If balance is a problem http://www.roman-road.co.uk/conversions/index.htm or something like it? They have rear wheel trike conversions for those lowriders as well. The conversions look like they can give you room to walk your feet better than the trikes designed as trikes.
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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Sat Oct 16, 2010 2:49 am

I've no idea if it would help at all, but I have a spare 20" front wheel fitted with a barely used Tongxin lightweight hub motor, a new Schwarbe Marathon tyre and a tiny 36V Tongxin controller. I don't have a spare 36V battery, unfortunately, but may have a spare throttle around somewhere. The Tongxin motors are light and quiet and seem reliable when run on 20" wheels, but less so when run on 26"/700C wheels for some reason.

This wheel fitted into the front fork of my recumbent fairly easily, although I did need to spring the fork out a bit to get it to fit (I think the hub is maybe 5 to 10mm wider at the axle than a standard front hub), but this was fairly easy to do and did no damage to the bike (I fitted the original front wheel back to it when I sold it a few months ago). There are pictures of my recumbent here and on the UK Pedelec site (http://www.pedelecs.co.uk/forum/electri ... =recumbent) that might give you an idea of what it looks like. It's essentially exactly the same unit that was used on the Brompton Nano, that is reviewed here: http://www.atob.org.uk/Electric_Buyers%27_Guide.html (8th one down on that page).

If you wanted to experiment, and always presuming that you could get hold of a 36V battery for a test, I could lend you the wheel and controller to see how you get on with it. I found it fine for what I wanted, which was essentially a bit of low speed and hill climbing assistance. I didn't really ever use it without pedalling, though, as the 'bent was very easy to cruise along on pedal power alone.

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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Sat Oct 16, 2010 8:12 am

The batteries I've used have all come from China. The 36V pack I used to run the Tongxin on is a Ping 36V, 10Ah pack, just about ideal for the job, as it comes complete with charger and battery management system - all it needs is a case and some simple wiring. Ping has a very good reputation, but his packs aren't the cheapest. He has an on-line shop, here: http://www.pingbattery.com/servlet/StoreFront . Customs seems to be a complete lottery - I've had to pay whacking charges on a small box valued at maybe £50 and yet had large packages (like around $1300 of Headway LiFePO4 batteries) arrive directly with no charges at all.

I can certainly dig the wheel out, give it the once over, test it and get it ready for you to try. I have the controller, I know, I just need to see if I can find a spare twist grip throttle for it - I'm sure I have one around somewhere and sort it out so that it will be as easy as possible to hook up. All you'd need would be a 36V battery - I guess for an experiment you might be able to just connect up three 12V sealed lead acid batteries and strap them on a rack, or perhaps better, in panniers. They'd be heavy and the range wouldn't be great, but they would be the cheapest way of seeing whether or not you can get on with the bike or not. If you could just borrow some for a test then that would be even better - there doesn't seem much point in spending a lot of money for a good battery if you don't get on with the bike.

Putting it together should be fairly straightforward, here's what I think would be involved:
1. The wheel should fit into the front forks (making sure it's the right way around) without too much difficulty - you'll probably need to slightly spring the forks apart to fit it. It then bolts in just like the standard wheel, but with conventional nuts on either side of the axle, which need to be well-tightened. The brake cable will need to be released by just popping it out of the lever to get the tyre and rim to slot between the brake pads, and the brake will then need to be adjusted properly once the wheel is fitted.

2. The controller is about the size of a packet of cigarettes, so can be temporarily zip tied anywhere on the frame that's convenient, or permanently mounted with the battery pack. All the connections are straightforward; there are just three colour coded wires, with bullet connectors, that connect the motor cable to the controller. There are two power wires from the throttle (red for positive and black for negative) that are connected to a 2 pin connector - I can make sure a suitable mating connector with leads is included. These just go directly to the battery, or better via a switch. For test purposes you could just use the connector to make and break power, rather than bother to wire a switch in. When I dig out the throttle I'll hard wire it to the controller. The only other connections on the controller are a pair of ebrake wires, which kill the power if a brake lever is pulled. These don't need to be connected to allow the thing to work and are very much a mixed blessing I think. Anyway, you need to buy a special brake lever with a switch in it if you wanted this function.

3. The battery pack would need to be mounted to something and wired up to the power connector. The easiest way to do this would be to get a seat post rack or bag that's big enough and tuck the batteries and the controller in that. The controller doesn't really get warm I found, as this isn't a super high power system. Fitting the battery pack securely is probably the biggest challenge, but to be honest it's no worse than finding a way to carry a bag of groceries on a bike. The best long-term, permanent, solution would be to buy a battery pack that would fit directly to the seat post. This one, from that site you listed: http://www.bmsbattery.com/index.php?mai ... ucts_id=17 would seem to be close to ideal, but I have no idea as to how good this supplier is (someone here will be certain to know, though, I'm sure). I'd go for the 10Ah pack at $177. It's rated at 20A maximum, which is fine for the 15A maximum that the little Tongxin draws. It looks like it should fit to your seat post fairly easily and it may have enough room underneath, or even inside, for the controller. It also has an on-off switch fitted, which further eases the wiring for you.

Having tried both recumbents and two types of conventional ebikes, I don't think there's much to choose between them, really. Two wheel recumbents are a real pain at low speed, as they lack the low speed stability that an upright bike has. This makes starting off on a slope and hill climbing a bit fraught, as it's easy to start wobbling around a bit - not nice in traffic. Once up to speed recumbents are fast and easier to pedal by far than an upright, mainly because their less affected by the wind. Adding a little bit of electric assistance transformed my recumbent at low speeds and made it a much nicer bike to ride, especially in traffic. I'm quite taken with my new electric folder, as well, though. I did a nice little 10 mile jaunt around the local countryside early this morning (sans gloves, which turned out to be a serious omission!) and it performed brilliantly. The only thing I'm going to change on it is the way the battery is mounted, as at the moment it's upsetting the way the rear suspension works on big bumps.

I'll try and dig out the wheel and controller and take some photos for you later today, if I get the chance.

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Re: Advice on E- Walker idea ?

Postby Samba » Sat Oct 16, 2010 11:31 pm

chekola wrote:
Samba wrote: A Bike without pedals - they push it and brake it with their feet and learn the balance and steering before they have to mess with pedals and brakes.

If you took something like a BMX bike and took off the chain and crank - you would have essentially the same thing in an adult size? That would take a regular hub motor. If you order a hub in a 20" wheel they may tune it for speed - You'd want one made for a 26" wheel - it will gain 30% more climbing power when put in a 20" wheel - and lower top speed.



Hey Samba,

Have I understood you correct ?

Are you saying that without the crank / chain there I could bascially put a motor from bike usually couldnt handle like a 26 " wheel and stick it on smaller frame like a bmx so I would have the adavantage of hill climbing i normally wouldnt get if i were to leave the chanin crank ?

ONly problem is where would i put my feet i.e. if any one say me with my legs dangling going at 20 plus mph , it might look suspicious :mrgreen:


You were looking for a 4 mph speed, assistance with walking, help with rough terrain and climbing.
If your motor is a direct drive, then it has low efficiency and power at very low speeds - like starting from a stop, climbing a hill at low speeds. If it has some internal gearing then it does a bit better at low speeds but its still designed to operate well at 15-20 mph - and low speed performance is secondary.

If you get a motor thats made for a 20" wheel - then its tuned for 335 RPM/20mph. A motor designed for a 26" wheel is tuned for 258 RPM/20mph.
On the small motors, they don't even intend that it should get you moving from a stop and want you to pedal up to 3 or 4 mph before starting the motor.

If you put a 26" motor on a 20" wheel - then you get a 20" wheel tuned for 258 RPM - about 14mph, it gives 30% more power for start-up and 4mph speeds than using a motor that was intended for a 20" wheel. Some motor companies don't mention the intended wheel size but give specs like RPM, high torque etc. You'd want the higher torque/lower top speed variety - better starting, climbing, low speed operation.

If the bike is designed as crank-forward, flat foot, foot forward, semi-recumbent, then you can use your feet on the ground behind the pedals. Otherwise, the crank is right under the front of the seat and gets in the way of walking while seated on the bike. If you want to walk on such a bike, you'd want to take the crank off. I don't see a copper bothering anyone who is walking a bike around at 4mph. But regardless, if you put even a small motor on a small bike its likely to go 10MPH or better and you'd want some pegs, stirrups or pedals to put your feet on.
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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Sun Oct 17, 2010 10:41 am

You'll need a lot more capacity than either of those two lead acid batteries have, I'm afraid, even for a test. I tried to run the Tongxin motor on three 4.5Ah 12V batteries when I first got it (only because I had them lying around) and found that the voltage sag just caused the low voltage cut-off on the controller to come on every time I opened the throttle, even with the batteries fully charged.

My guess is that you will need at least 12 to 15Ah sealed lead acid batteries as the minimum, just to be able to pull the 15A that the controller and motor will need when accelerating. These will be heavy, probably around 4kg each (and you need three to get 36V, so the whole pack will weigh around 12kg or so) and are likely to cost around £25 or so each, maybe a bit more. They will also only have a relatively short life on an ebike, maybe a year or so before the range starts to drop to the point where they aren't much use.

I hope that the pack you've been offered looks OK, as that would definitely be the best option (assuming that it's something able to deliver the current needed). I didn't get a chance to test the motor and controller today, unfortunately, but with luck I should be able to get on to it tomorrow. The good news is that I've found a twist grip throttle for it, so all the parts are there, barring the battery pack.

One source I've used for batteries in the past is www.component-shop.co.uk . They have some 12Ah batteries that might do the job: http://www.component-shop.co.uk/html/bo ... v12ah.html at £81.50 including shipping and VAT for three. To be honest, the difference in price between these and the 10Ah BMS Battery pack seems small enough to take a risk on buying from China. The BMS Battery 36V, 10Ah pack (this one, in 10Ah: http://www.bmsbattery.com/index.php?mai ... ucts_id=17 ) for $177 seems a better deal than buying sealed lead acid batteries, especially as it comes with a case and charger and will be a great deal lighter than the lead acid batteries, give much greater range and probably last longer as well.

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Re: Advice on E- Walker idea ?

Postby amberwolf » Sun Oct 17, 2010 2:01 pm

chekola wrote:LIthium it is then , which funnily enough is something occassionally take to help the blues.

See? Lithium makes *everything* lighter and more energetic! :lol:

Really, though, unless you (like me) just couldn't afford anything more than lead, any other common chemistry is better: NiCD, NiMH, Li-(any). I just tested this theory on CrazyBike2,
viewtopic.php?p=323589#p323589
after having used SLA to run it for all it's previous time, now it has NiMH. A tiny little pack, only 9Ah vs the 17Ah it had with SLA, but the weight difference is astounding, as is the handling difference. Efficiency difference isn't directly comparable as it is a different motor and drivetrain, too, but even there I suspect it'd be at least 1/3 better efficiency, and more likely twice as efficient. :)

The only thing lead works better at is forklifts and the like, and some of the powerchairs and such that need a really good ballast to keep them stable on side-tilting slopes and when the rider is leaning out of the seat to the side reaching for something, etc. And possibly tractors for the same reason--more traction from weight. :)

Regarding things like schematics or disassembly procedures/etc. for things like your knee walker, if you have questions about stuff like that ask me, and I'll see if I can find out, as I know some people in the industry doing repairs and stuff that might be able to get that info for me.
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Re: Advice on E- Walker idea ?

Postby el_walto » Sun Oct 17, 2010 11:13 pm

It would not be an easy task to convert that walker to electric. Is there a reason you can not use a mobility scooter?
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Re: Advice on E- Walker idea ?

Postby amberwolf » Sun Oct 17, 2010 11:20 pm

chekola wrote:Im not too well versed on batteries and my mathematical skills hardly help ( i suffer dyscalculia ) so I tend to struggle remembering and making sense of most number related things ( not useful skill ) but theres not much I can do about Im afraid , other than try .

I am not great with math either, though not for that reason--I just have trouble following it and often have trouble enough even with simple things, such as not always getting 5 when I add 2 and 2. ;)


NimH always makes me think of those smalle batteries like the AA , I havent really looked into so I'll be sure to check it your thread , if its cheap and easy to wire up for use - then why not ?

If you get NiMH rated for EV use, high-current types, then they can be really good. The F-cell size is the only ones I'd really recommend for it, which typically are 13Ah, where the D size would be around 9Ah. There are potential problems with Ni chemistries as well as any other, of course, such as the fact that they get very hot during the last phase of the charging cycle, and the charger must read a thermistor that is part of the pack to tell when this happens so it can stop charging them. I wouldn't recommend charging them in an enclosure for that reason (though I am sure many people do it safely, I am leery of doing so, and actually run a fan on them at that point in the charge cycle so they don't have to stay hot for long, as heat ages all batteries faster).

NiCD is another option, and is more readily available at reputable dealers like ebikes.ca.

Both are still heavier than Li types, and may have shorter lifespans depending on usage. Both have less power density than Li, and have a lower "C rate", or ability to deliver high currents, so will take more of it to do the same thing as Li.


Here are some pics today I took of the wheel setup just to give you an idea ( sorry about the quality, I dont have zoom-in lens )
http://www.flickr.com/photos/28633046@N02/

Looks like the typical kind of wheel you'd see in almost any personal medical equipment, like the ones I have here from various walkers and wheelchairs.

To change them out for air-filled (pneumatic) tires, you'd probably want to check out hardware stores that sell new wheels for dollys and utility carts. Many (but not all) have the same axle diameter as those wheels probably do (7/16", if they're like mine, or maybe 10mm). If you want much larger diameter wheels, you might try finding a used jogger's stroller, which typically has three bicycle type wheels on it. So far the ones I have found at thrift stores have 10mm axles, with bearings just like those in the walker/wheelchair wheels, and thus they will go right onto the axles that those came off of.

If the axles aren't long enough, well, there's a good chance that the axles on the stroller are the same thread pitch as the ones on the walker, and you may be able to swap them out, wheel, axle, bearings and all.

The catch is that now your knee walker would be several inches higher off the ground, as most of those wheels are 12" to 16". ;)


If you can get them to answer you, Goldenmotor makes some small diameter hubmotor-wheels intended to directly power mobility scooters of various types, which may well be able to bolt right into place on your walker. Go here:
http://goldenmotor.com/hubmotors/hubmotorIndex.html
and scroll down a ways. There is a 6" diameter brushed geared motor that would probably work, if the axle size is right. If not, you could make an adapter plate/bracket that would bolt to your original axle mount and clamp to the frame, that would then bolt the motor to it.

BTW ** Who exactly is TVE , I notice you mention them a lot but I didnt find any companies under that name , unless it abbrevations .

I'm sorry--I abbreviate a lot, especially with my bike names. So you will see TVE for The Velcro Eclipse
viewtopic.php?f=2&t=20595&start=0
DGA for DayGlo Avenger
viewtopic.php?f=2&t=15570
and CB2 for CrazyBike2
viewtopic.php?f=2&t=12500

I did see this http://www.electricbikekitz.com/product_info.php?products_id=50 but it doesnt seem that much cheaper than a lithuim , unless the place you get is selling them a lot cheaper. ??

I've been fortunate enough to have most of my batteries donated to me after they were used by other people (who presumably moved on to bigger and better batteries), and the old SLA from UPSs and things. If it werent' for that I probably would still be only running lead-acid (SLA) and not getting nearly the performance that I am now. :)

That particular link looks fairly expensive for that battery, but it is already fully assembled into a pack with a box and switch and plugs, so it's convenient and ready to install. Making an equivalent pack from RC LiPo packs from HobbyCity/HobbyKing would probably be cheaper or the same price, and would be able to supply much higher currents when needed (like starting from a stop). And their stuff just keeps getting cheaper and cheaper, and better and better, from what I've been able to tell reading this forum the last year or so.

It looks like ebikes.ca has discontinued the only NiMH they had carried, a 36V 12Ah Nexcell NiMH, whcih was $425. Roughly equivalent price per energy unit to the one you linked. All their NiCD seems to be sold out right now, too. You might ask when or if they will get more NiMH in, if you're interested in that chemistry.

Realistically, if buying new, RC LiPo will probably get you the best deal for the longest lifespan, once you read up on the potential pitfalls of it and make sure you have a proper charger and LVC (low voltage cutoff) for it.
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Re: Advice on E- Walker idea ?

Postby Jeremy Harris » Wed Oct 20, 2010 4:42 am

chekola wrote:Just a quick to Jeremy here .

That guy still hasnt checke the capacity ,and is sounding less enthusiastic about it than he did on Sunday -ho hum :roll:

Looks like I'll be ordering from China or trying amberwolfs idea.

che


I may have a possible solution for you re: a battery pack. I've decided to switch to a higher power LiPo pack on my folding bike (I've decided that I like the bike, but want more power!) so may have my 36V 10Ah Ping pack and charger available (it's the black fibreglass box on the picture in this thread: viewtopic.php?f=6&t=21945). I'm waiting for the new batteries to arrive from Hong Kong, but as soon as they do I could take the pack off the bike. This is the pack that I used to run the Tongxin motor with on the recumbent, it probably has about 200 to 300 cycles on it, and, given the gentle use it's had, I should think it will be OK for maybe another 1000 cycles or more before it starts to lose capacity.

It'd be pretty easy for me to make up the wheel, controller, throttle and battery pack as a simple "plug and play" set up, then all you'd need to do is swap out the front wheel, fit the throttle to the handlebars and strap the battery back to a rear rack. It weighs about 3kg, so isn't too heavy - much, much lighter than the equivalent weight of lead acid - maybe a 1/4 of the weight.

Jeremy
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Re: Advice on E- Walker idea ?

Postby MikeB » Tue Oct 26, 2010 8:11 am

chekola,

How's your sense of balance?

I just ran across this announcement of a self-balancing electric-powered unicycle, and thought it might be an interesting alternative for you.
http://green.autoblog.com/2010/10/26/vi ... -electric/

The unicycle has the advantage of a very small footprint, meaning that you can navigate in tighter spaces. It also keeps you very upright, so your head is roughly at the same level as people standing around you. The wheel looks large enough to handle mildly rough terrain, but I have no idea if it's got enough torque to handle hills. But since you're already investigating low-speed high-torque motors, you may be able to tweak that.

Of course, it could be a real disaster if the self-balancing mechanism fails, especially if you have a limited ability to catch yourself in a fall. And getting onto the sbu might also be a challenge, depending on the specific effects of your disability.
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Re: Advice on E- Walker idea ?

Postby Lock » Thu Apr 28, 2011 10:15 pm

My disability ( still undiagnosed ) is of muscoskeletal origins primarily and prevents me from standing or walking .
At one time i could manage to do it with crutches but , not any more though I can sit ie cycle and walk provided my pelvis is immobilsed / supported ( which is why kneewalker allows me to walk )
I have since puchased my knee walker and being using it very successfully so far with a crutch for balance , the only problem is that wheels are like the sort of hard plastic you find on skateboards , so it tends to stop when hits something i.e. like small stones or rough terrain , which is not so good ( think sudden jerking of the handlebars , constant looking down at the path )
Any way, as you can see Im back again because I wanted to persue this idea Ihad of trying to incorperate a small hub motor that could assist me uphills or even freewheel i.e. without having walk if need be.


Helena... I haven't been following this thread really, but seems to me ya should be comfy as recumbent on three wheels... The rest of it aka power-assist for hill-climbs/distance is the minor secondary concern. Fair to say?

LocK
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Re: Advice on E- Walker idea ?

Postby HoverBoarder » Fri Apr 29, 2011 9:42 am

chekola wrote:Alternatively I could try and got for a simpler design such as below which would basically take away the additional knee rest support along with 10 lbs off the weight so it was done to 20.. problem is portability ( it would still need to disassemble and the fact it looks pretty unstable - esp if I even attempted to add motor.

http://cgi.ebay.com/Seated-Turning-Knee-Scooter-Walker-Turning-Leg-Caddy-/190398067909?pt=LH_DefaultDomain_0&hash=item2c549bf4c5
:(

che


Hi chekola.

I came across the same seated knee walker, and I thought that this would be much better and more comfortable than the knee scooters or roll-a-bouts. This site has good videos of the products working as well. http://www.goodbyecrutches.com/products/seated-scooter/

As an alternative, what about a three wheel electric scooter?

Image
http://www.smallworld-us.com/seated-folding-electric-scooter3-wheel-hb075start-from-5-unitsfree-shipping_p40814.html

or this

Image
http://www.spinlife.com/Pride-Go-Go-Ultra-X-3-Wheel-Travel-Scooter/spec.cfm?productID=79592


Just a thought....
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Re: Advice on E- Walker idea ?

Postby HoverBoarder » Sat Apr 30, 2011 8:46 am

chekola wrote:
HoverBoarder wrote:That seated scooter is bad idea IMO , I only posted it because it was lighter than my current one but the stress it would put on my groin would make it useless, just try pushing off with one leg up like that compared to kneeling and you will see the difference.

I already have mobility scooter called liteway 3 , unlike the knee walker though its not really portable , you cant use it manually and the low clearance means your restricted to town pavements at best - I want to go offroad more , forests , im sick of towns - i live in one but id take the country any day.

thanks for your suggestions any way.

che


I like your plan to get out and explore the trails, and I see your point on the awkward movement for the seated leg walker.

If I might try a few more guesses, you noted that your current knee walker has plastic wheels that have a hard time on the street because it brings you to sudden stops due to small rocks; much less being able to be used on trails. This could be helped dramatically by replacing the wheels with much better ones. Either by having one to two wheels with a hub motor like the GoldenMotor small wheel hub motors discussed earlier on this thread, or a similar small wheel motor from another vendor. Although even just having all of your wheels replaced with new wheels - ideally with some tread - would go a long way towards reducing the amount of energy that is lost. Allowing you to go farther with less effort.

Still, I am a little worried about the extra weight from an electric assist in this application. If you do go the electric route, I would suggest only having one or maybe two hub motors, and if at all possible use LiFePo4 or other Lithium batteries to reduce weight. You also would want to make sure that you have a good frame that can support the electric assist equipment.

The biggest factor hands down in the usability for what mobility assist device that you choose though is going to be the type of wheels that are used.


Here are two different walker models that both look pretty good for going on trails and have space for electric assist as well.

First is a knee and leg walker that already has some pretty decent wheels (although I still would suggest upgrading them for use on trails) and a good frame.

Free Spirit Knee and Leg Walker
http://www.amazon.com/Essential-Medical-Supply-Spirit-Walker/dp/B001CBA2BI/ref=sr_1_111?s=hpc&ie=UTF8&qid=1304167975&sr=1-111
Image

Second is a mountain walker from Trionic. This seems like it might be a good option for you if a stand up walker system is something you could use. There is a whole series of walkers from Trionic, and the thing I liked about them was the 'climbing wheel' system that allows it to climb up 5 inch high obstacles like curbs.

If you could use a stand up walker system, maybe with the help of knee braces like the P3 system or other high quality knee braces, than this might be a good option for you. Look at those great wheels :-)

Trionic Mountain Walker
http://www.xsmedical.com/Trionic_Mountain_Walker_p/trionic-3.htm
Image
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Re: Advice on E- Walker idea ?

Postby HoverBoarder » Sat Apr 30, 2011 12:27 pm

Here's one that looks pretty fun.

A seated electric scooted that you can fold up and take as luggage at the airport. Cool!

Luggie Scooter

http://www.xsmedical.com/FreeRider_Luggie_Scooter_p/luggie.htm

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Re: Advice on E- Walker idea ?

Postby newb » Sat Apr 30, 2011 5:49 pm

I have only read the first couple posts and the last few so i really dont know how practical this might be but i thought i'd put this out there. what if u had someone set u up w/ a system something like this on ur knee walker? fairly simple, super lite and w/ a gear reduction plenty of torque. Just a thought.


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