I know so much more now. I didn't know that you could really put an e-bike together for roughly $500. Think about what you can do if you were really light on money. You could buy a cheap motor that only went 20 mph. Then buy a light switch then about $100 worth of SLA batteries. You could use the light switch as a controller and then just flip the switch when you wanted assistance and since the bike only went 20 mph, it wouldn't really put you in danger. You wouldn't want to try that with a really powerful motor. It wouldn't be as fun without a throttle but you could still do it. And then if the light switch broke, it could easily be replaced for very cheap.
Really cheap ways to get into e-biking
- Thread starter morph999
- Start date
AussieJester
1 TW
Or... you could buy a $28 dollar 24volt Unite Motor from TNC Scooters, a 24v controller for $15.50 while your at it pay 8 bucks for a throttle all for a dollar over a 50 bill throw in your 100 bucks worth of SLAs and you have the main components for an e-bike for 150 bucks (plus 10-20 bucks freight i guess) 
I wonder why some people bother trying to use odd motors for e-bikes, treadmill motors, fan motors car starter motors etc when the real deal so cheap ;-S
KiM
I wonder why some people bother trying to use odd motors for e-bikes, treadmill motors, fan motors car starter motors etc when the real deal so cheap ;-S
KiM
we should have a contest to see who can make a e-bike for the cheapest money.
How much energy do you think a controller uses? Do you think using a light switch would be a lot more efficient than using a controller? Or about the same? I probably won't ever make a bike like that but you never know. I'd be the kind of guy to do it. I like simplicity. The older I get the more I try to simplify my life. I don't even open mail anymore unless it's bills. lol.
How much energy do you think a controller uses? Do you think using a light switch would be a lot more efficient than using a controller? Or about the same? I probably won't ever make a bike like that but you never know. I'd be the kind of guy to do it. I like simplicity. The older I get the more I try to simplify my life. I don't even open mail anymore unless it's bills. lol.
Why is this in Toxic Discussions? It seems like a pretty valid Technical topic to me, or at worst, General.
If it hadn't come up on the View New Posts page I would not have seen it.
Anyway, if you want really cheap ways to do it, you should be perusing my Electricle project blog.
I actually *did* do the switch-controlled assist, before I rebuilt a smoked PWM controller off a dead scooter.
The light switch would be more "efficient" than the controller, as far as power loss goes, but it is not possible to do that using a brushless motor, only with a regular brushed DC motor. Note that it doesn't have to be a *permanent magnet* DC motor, only a brushed one, so you can use a vaccum cleaner or weedeater or drill motor as well, or any other series or shunt wired wound-field motor, as well as the usual PMDC types.
And you don't have to buy batteries at all. Just go find people throwing out blown up server-sized UPS backups; they'll have some good-sized batteries in there, often (like mine) 12V 18Ah, and you might get 4 of them, or (like mine) even 8! Since 6 of mine were still good, that's 2 36V 18Ah sets of batteries for nothing. No, they won't last more than a few months, maybe half a year per set, at my usages, probably, but if they cost nothing, what does it matter?
AJ, the reason some of us use wierd stuff for our bikes is because we can't afford any better than whatever we can scrounge.
Some of us do it because we like the challenge.
Some of us do it just so we can say we did it, and watch the goggly-eyes around us.
Some of us do it for *all* those reasons.
As far as the cheapest goes, well, the only cost I have in mine is the welding wire to put the frame together, and the cutting and grinding wheels to cut and shape pieces of frame/etc. Plus a few dollars (literally) on some thrift store items used for many parts for different projects (thus splitting the cost between them)
Everything else came from Freecycle, friends, garbage, alleys, roadside finds, stuff I already had laying around for years unused or broken, and so on.
I bought most of the LEDs used in some of the lighting, but even *that* came off a previous bike, and so was not originally spent on this one (this one started out using just some Honda scooter lighting, including the turn signals and flasher that are still being used on it now).
(none of this says I wouldn't *want* some new parts, but not having any money to spend on things can make you *very* good at figuring out how to do this without using any!)
If it hadn't come up on the View New Posts page I would not have seen it.
Anyway, if you want really cheap ways to do it, you should be perusing my Electricle project blog.
I actually *did* do the switch-controlled assist, before I rebuilt a smoked PWM controller off a dead scooter.
The light switch would be more "efficient" than the controller, as far as power loss goes, but it is not possible to do that using a brushless motor, only with a regular brushed DC motor. Note that it doesn't have to be a *permanent magnet* DC motor, only a brushed one, so you can use a vaccum cleaner or weedeater or drill motor as well, or any other series or shunt wired wound-field motor, as well as the usual PMDC types.
And you don't have to buy batteries at all. Just go find people throwing out blown up server-sized UPS backups; they'll have some good-sized batteries in there, often (like mine) 12V 18Ah, and you might get 4 of them, or (like mine) even 8! Since 6 of mine were still good, that's 2 36V 18Ah sets of batteries for nothing. No, they won't last more than a few months, maybe half a year per set, at my usages, probably, but if they cost nothing, what does it matter?
AJ, the reason some of us use wierd stuff for our bikes is because we can't afford any better than whatever we can scrounge.
Some of us do it because we like the challenge.
Some of us do it just so we can say we did it, and watch the goggly-eyes around us.
Some of us do it for *all* those reasons.
As far as the cheapest goes, well, the only cost I have in mine is the welding wire to put the frame together, and the cutting and grinding wheels to cut and shape pieces of frame/etc. Plus a few dollars (literally) on some thrift store items used for many parts for different projects (thus splitting the cost between them)
Everything else came from Freecycle, friends, garbage, alleys, roadside finds, stuff I already had laying around for years unused or broken, and so on.
I bought most of the LEDs used in some of the lighting, but even *that* came off a previous bike, and so was not originally spent on this one (this one started out using just some Honda scooter lighting, including the turn signals and flasher that are still being used on it now).
(none of this says I wouldn't *want* some new parts, but not having any money to spend on things can make you *very* good at figuring out how to do this without using any!)
TylerDurden
100 GW
DISH
10 W
- Joined
- Oct 19, 2009
- Messages
- 94
BMS Battery 12 MOSFET 500 watt controller pulls around 44 ma at 36 volts (approx. 1.5 watts) to run the controller. Makes no difference if the throttle is off or full on. Cost is around 25 $US.morph999 said:
http://endless-sphere.com/forums/viewtopic.php?f=4&t=13691
I've actually seen a few people try connecting a DC motor directly to the battery using a switch. You can sometimes get away with this if the motor is underpowered and / or the voltage is low enough. However, even a 250 watt geared scooter motor has been known to break chains when connected directly to a 24 volt battery. That is if the chain doesn't jump off the gear.
What a few have done is have several batteries in series and start the motor by connecting it to the first battery, then switch it to the next higher voltage tap, and so on as the speed comes up. That greatly reduces the sudden burst high torque issue.
You need to be careful as to what kind of switch you use. Motors pull a LOT of current when starting and produce high voltage arcs when the switch is opened. It's not uncommon for the switch contacts to become spot welded in the ON condition, meaning you find yourself going down the road at maximum speed with no way to stop. Unless of course your brakes are capable of stalling the motor which can then make the wiring overheat and catch fire.
You can do it but BE CAREFUL!!!
dogman dan
1 PW
It can be done for sure. The two main flaws are that the switch melts, often in the ON position. On 24v the switch may last awhile, but above that, not very long. The other flaw is that the motor with no controller tends to really pull a lot of amps, which hammers the doo doo out of batteries. Only works with sucky brushed motors of course.
But this approach has been known to work well, usually with a small motor and some big ol golf cart batteries. Actually, early golf carts worked exactly that way. They used a throttle that was a series of really beefy contactors, and several different resistors for different speeds. They used 36v and the motors were kinda small compared to modern carts that use 48v and much bigger motors with controllers.
Morph if you want to have a contest, I bet I can win. I have a cordless skillsaw around( freebie) some bikes that cost less than $20, and my wife recylcles all the batteries for the local colledge, and some switches that were scavenged too. We've been dedicated dumpster divers for 40 years. I bet I could get it under $50, and only because tires cost some money. Range might be only around the block though.
But this approach has been known to work well, usually with a small motor and some big ol golf cart batteries. Actually, early golf carts worked exactly that way. They used a throttle that was a series of really beefy contactors, and several different resistors for different speeds. They used 36v and the motors were kinda small compared to modern carts that use 48v and much bigger motors with controllers.
Morph if you want to have a contest, I bet I can win. I have a cordless skillsaw around( freebie) some bikes that cost less than $20, and my wife recylcles all the batteries for the local colledge, and some switches that were scavenged too. We've been dedicated dumpster divers for 40 years. I bet I could get it under $50, and only because tires cost some money. Range might be only around the block though.
AussieJester
1 TW
dogman said:
You sure about that
I have a full scooter sitting here from kerbside and nearly a dozen kerbside bikes, 8 20v 20ah slas (4 donated) a weldser a bender and an angle grinder...i think i could do it for nothing and get around the block more than once LoL ;-PKiM
liveforphysics
100 TW
Switch = bad idea. Even that awesome guy from Pakastan ditched the switch idea and made a PWM controller for like $5.
If you make something too crappy, you may as well invest the DIY E-kit money towards a lighter weight pedal bicycle.
When I test-rode some weenie powered bionix kit bike, I remember feeling that a standard racing pedal bicycle felt much better to ride, dispite lacking the tiny bit of electric torque the much heavier and clumsy feeling E-bike had.
If you make something too crappy, you may as well invest the DIY E-kit money towards a lighter weight pedal bicycle.
When I test-rode some weenie powered bionix kit bike, I remember feeling that a standard racing pedal bicycle felt much better to ride, dispite lacking the tiny bit of electric torque the much heavier and clumsy feeling E-bike had.
AussieJester
1 TW
liveforphysics said:
Naeeem ...what an incredibly resourceful fellow he is! I wonder how hes getting on with that fork he designed and wished to build, havent heard from him for awhile, he refused all offers of help to wanting to do it on his own! I hope we hear back from him soon would be awesome to see what hes come up with now! be something equally amazing im sure.
KiM
Russell
1 MW
For a low cost way to get into ebikes buy an iZip Mountain Trailz from Walmart for $299+Tax!
http://www.walmart.com/catalog/product.do?product_id=12082032
-R
http://www.walmart.com/catalog/product.do?product_id=12082032
-R
dogman dan
1 PW
Well, yeah, a dumpster found ebike or electric scooter would be the cheapest way. But I have a 50 year record for being incredibly cheap. You try living on Las Cruces wages sometime. I considered the frankenbike route at first, but decided it wouldn't make it up the hill I live on.
Most likely the cheapest really practical way into ebiking still remains the I-zip. If you can stand the god awfull racket of one. After that, probobally the ebay kits, WE or golden etc, that come with some sla's for around $400.
Most likely the cheapest really practical way into ebiking still remains the I-zip. If you can stand the god awfull racket of one. After that, probobally the ebay kits, WE or golden etc, that come with some sla's for around $400.
Drunkskunk
100 GW
I built my 9C equiped bike for $203.
Its probable that a brushed could be built for free from salvage.
But a switch is a bad idea. A motor will pull full amps at start up. Since there is no back EMF, it's starting voltage is a factor of the Voltage devided by the coil resistance. If the coil resistance is 0.1 ohms (that would be a small motor) then you have 360 amps being pulled from a 36v battery. Very few batteries can survive that for long.
Its probable that a brushed could be built for free from salvage.
But a switch is a bad idea. A motor will pull full amps at start up. Since there is no back EMF, it's starting voltage is a factor of the Voltage devided by the coil resistance. If the coil resistance is 0.1 ohms (that would be a small motor) then you have 360 amps being pulled from a 36v battery. Very few batteries can survive that for long.
Russell
1 MW
My least expensive conversion cost roughly $500.
GM 250W motor: $139
CR18 rim/DH13 spokes/nipples: $90
Trigger throttle: $30
Controller*: ~$40
3 Bosch Fatpacks 36V/6Ah: $119
Charger: $24
Bag*: ~$30
Misc: ~$30
Total: ~$502
The second conversion:
Bafang 250W motor*: $139
Rhyno Lite rim/14G spokes/nipples: $65
Trigger throttle: $30
Controller: $55
48V/10Ah LiFePO4 w/charger: $272
Bag: $50
Misc: ~$35
Total: ~$646
*estimated cost, was part of first kit
Then there's the cost of the base bikes, one of which I built from the frame up with individually purchased parts and the other which I bought new then replaced the entire drivetrain and then some. I won't even mention how much they ending up costing since this thread is supposed to be about cheap ways to get into ebiking and that was not my priority. Still when the costs are itemized it drives home just how inexpensive the iZip really is, I was even thinking about getting one as a beater ebike...but then I've got a 9C and a couple of spare controllers and throttles and what not just waiting for ebike #3. I'm thinking of going the cheap route this time and using a Schwinn Sidewinder ($159+tax) as the base bike.
http://www.walmart.com/catalog/product.do?product_id=11089191
Projected costs:
Bike w/tax: $167
Double leg kickstand: ~$35
Topeak MTX rack: ~$30
Total base bike cost: ~$232 (all new expenditures)
9C front motor: ~$100
Wheel build: ~$65
Throttle: ~$15
Controller: $44
Torque arm: $25
Misc: ~$25
Conversion cost: ~$274 ($115 in new expenses)
Total: ~$506
... Plus choice of existing 36V/9Ah SLA (~$100), 36V/6Ah LiMn ($143) or 48V/10Ah ($272) LiFePO4 in Topeak bag ($50)
Even going the inexpensive route doesn't end up being all that cheap when it's all added up.
-R
GM 250W motor: $139
CR18 rim/DH13 spokes/nipples: $90
Trigger throttle: $30
Controller*: ~$40
3 Bosch Fatpacks 36V/6Ah: $119
Charger: $24
Bag*: ~$30
Misc: ~$30
Total: ~$502
The second conversion:
Bafang 250W motor*: $139
Rhyno Lite rim/14G spokes/nipples: $65
Trigger throttle: $30
Controller: $55
48V/10Ah LiFePO4 w/charger: $272
Bag: $50
Misc: ~$35
Total: ~$646
*estimated cost, was part of first kit
Then there's the cost of the base bikes, one of which I built from the frame up with individually purchased parts and the other which I bought new then replaced the entire drivetrain and then some. I won't even mention how much they ending up costing since this thread is supposed to be about cheap ways to get into ebiking and that was not my priority. Still when the costs are itemized it drives home just how inexpensive the iZip really is, I was even thinking about getting one as a beater ebike...but then I've got a 9C and a couple of spare controllers and throttles and what not just waiting for ebike #3. I'm thinking of going the cheap route this time and using a Schwinn Sidewinder ($159+tax) as the base bike.
http://www.walmart.com/catalog/product.do?product_id=11089191
Projected costs:
Bike w/tax: $167
Double leg kickstand: ~$35
Topeak MTX rack: ~$30
Total base bike cost: ~$232 (all new expenditures)
9C front motor: ~$100
Wheel build: ~$65
Throttle: ~$15
Controller: $44
Torque arm: $25
Misc: ~$25
Conversion cost: ~$274 ($115 in new expenses)
Total: ~$506
... Plus choice of existing 36V/9Ah SLA (~$100), 36V/6Ah LiMn ($143) or 48V/10Ah ($272) LiFePO4 in Topeak bag ($50)
Even going the inexpensive route doesn't end up being all that cheap when it's all added up.
-R
How about a push-trailer for super cheap? I'm not suggesting that anyone would be "happy" with it for any length of time, but it could be a useful intro to E-bikes. TNC-style motors can be found cheap on EBAY when kids upgrade to a more powerful motor, usually half the price of new (and new TNC motors are pretty cheap).
Brushed systems are a little less efficient, but the brushed controllers are VERY cheap. I got a used steel hand-cart dolley for $5 at a thrift store (used items sold for charity), the aluminum skillet for the chainring adapter disc was $1, and a 20" BMX bike is not hard to find free in the trash (or CraigsList) if you're patient...
Hey, where's amberwolf? His blog is very long, but perhaps he could post his top 10 tips in one paragraph?
Brushed systems are a little less efficient, but the brushed controllers are VERY cheap. I got a used steel hand-cart dolley for $5 at a thrift store (used items sold for charity), the aluminum skillet for the chainring adapter disc was $1, and a 20" BMX bike is not hard to find free in the trash (or CraigsList) if you're patient...
Hey, where's amberwolf? His blog is very long, but perhaps he could post his top 10 tips in one paragraph?
Russell said:
I was thinking more about longevity. Motors tend to last a long time. Right? I didn't think about a brushed motor, though. I was thinking that if you had a motor and then some cheap switch or two cheap switches and some batteries, there wouldn't be as many expensive parts to replace. There's really only one expensive part and that's the motor. YOu can get cheap batteries if you had to.
Russell
1 MW
Morph,
There are very good reasons why people have migrated to brushless motors, increasingly use more sophisticated controllers and lightweight lithium batteries but hey if you want to go back in time and use a brushed motor controlled by a switch and run it all on lead that's your prerogative. BTW do you want a computer with a Pentium 100Mhz cpu and Windows 95 as well?
I sense you are looking at your X5 motor and the prospect of having to fork out many hundreds of dollars for a battery with sufficient capacity to run the beast and wondering if it's worth it...is that it bunkie?
-R
There are very good reasons why people have migrated to brushless motors, increasingly use more sophisticated controllers and lightweight lithium batteries but hey if you want to go back in time and use a brushed motor controlled by a switch and run it all on lead that's your prerogative. BTW do you want a computer with a Pentium 100Mhz cpu and Windows 95 as well?
I sense you are looking at your X5 motor and the prospect of having to fork out many hundreds of dollars for a battery with sufficient capacity to run the beast and wondering if it's worth it...is that it bunkie?
-R
Drunkskunk
100 GW
morph999 said:
Brushless motors can't be run on a switch for the same reason you can't run a car without a distributor.
Brushed motors are cheap to free if you are resourcefull or patient.
That leaves me out.morph999 said:
But if the contest is just for the cheapest, period, then there will be many winners who do things like me. If the welding and cutting materials for the frame aren't included, it was nearly free.
My first ebike actually cost more than my current one, because I bought the radiator fan motors at a junkyard, and several of the control and battery parts came from a fried ScootNGo I bought from a thrift store for more than I should have (but didn't realize it was actually that badly destroyed).
As for the switch vs controller: On my first version of DGA, I used two lightswitches, one to switch each of two radiator fan motors into the circuit (parallel), for "dual speed" control. It wasn't all that effective, but it did work, using 36V worth of 12V 12Ah SLA. I never had the switches weld, but I also tried not to turn it on from a stop, only from already-moving, to reduce the shock load on the system.
I also tried out a contactor (relay) controller, to switch in more or less batteries, and to switch the motors in and out, but none of the relays I had were rated for above 24VDC on the contacts, and I *did* have problems with the contacts welding together. Parallelling them didn't work because of the small delays in the different relays (even identical p/n's didn't switch at exactly the same time). With good enough relays, it would have worked.
If trying to do this for nothing, it's hard to find good enough relays for free, while it is easy to find relays to handle 24VDC @ 15-30A (they come in many UPS battery backups, which are also a source for batteries if you find them fried from storms/etc rather than age). If you have to *buy* the relays (new, at least), it'd be cheaper to buy a cheap controller, and it'll work better too.
Another option is to use a giant wirewound potentiometer, like those used in lighting dimmers:
Problem is, it weighs as much as some people's whole (non-e)bikes.
But it'll handle up to 2500W @115VAC, 20A.
Even if you derate that for DC, it should still work for small motors (which will weigh *less* that *it* does!).Attachments
As for batteries, you could build a NiMH or Li-Ion pack for nothing, if you are patient enough. It won't be great, but it might be better than the used UPS batteries.
Scrounge up all the old laptop batteries you can find, gut them, and see what cells they have in them. If you cut the tabs carefully so you have enough on each cell to solder to, you eliminate having to have a tab welder or soldering directly to the cell body.
No BMS? Well, there's one in each laptop battery, but that might be dead and the reason for it being chucked. Celphone batteries each have a BMS in them, so you could in a pinch use that to charge the Li-Ions up, but you first need to find the specs for the cells out of the laptop batteries, then the specs for the celphone cell, so you know if the voltages are the same so you don't blow anything up.
And do all these experiments outside.
Wire up that BMS to the laptop cells using the celphone battery case, one at a time, and charge them up with the celphone. Celphones can be found on the side of the road with broken screens and whatnot every so often, and also on Freecycle (if you don't see any listed, put a Want ad up, and you'll probably get a lot of responses) and Craigslist.
Series/parallel all the ones you find are still good, into a pack that has the voltage and Ah you need for your desired range and speed, with whatever motor you've salvaged out of that treadmill, weedeater, or lawnmower.
Scrounge up all the old laptop batteries you can find, gut them, and see what cells they have in them. If you cut the tabs carefully so you have enough on each cell to solder to, you eliminate having to have a tab welder or soldering directly to the cell body.
No BMS? Well, there's one in each laptop battery, but that might be dead and the reason for it being chucked. Celphone batteries each have a BMS in them, so you could in a pinch use that to charge the Li-Ions up, but you first need to find the specs for the cells out of the laptop batteries, then the specs for the celphone cell, so you know if the voltages are the same so you don't blow anything up.
And do all these experiments outside.
Wire up that BMS to the laptop cells using the celphone battery case, one at a time, and charge them up with the celphone. Celphones can be found on the side of the road with broken screens and whatnot every so often, and also on Freecycle (if you don't see any listed, put a Want ad up, and you'll probably get a lot of responses) and Craigslist.
Series/parallel all the ones you find are still good, into a pack that has the voltage and Ah you need for your desired range and speed, with whatever motor you've salvaged out of that treadmill, weedeater, or lawnmower.
Russell
1 MW
morph999 said:
Morph,
Name calling, I don't recall calling you a "name" unless you are referring to "Bunkie" and that's more of a whimsical term of familiarity or at least that's the way it was intended. You do post a lot and quite honestly some of it is pretty silly, which is fine, but if you post something I know is flat out wrong I might just chime in. We both got started with ebike conversions about the same time so I do follow your progress. As for me having money to spare, I don't and none of my stuff are high ticket items, furthermore I believe your X5 cost more than one of my conversions. Of course if you remember way back everyone told you if you wanted to go fast it was gonna cost you big bucks and now you're wondering if e-biking can be done on the cheap. At some point you're going to have to figure out what you want and that isn't just true with this hobby.
Good luck,
Russ
Drunkskunk said:
right, u need 3 switches & 4 hands.
actually there is a way u can run a brushless motor with only one switch.
amberwolf's radiator fan motors set off the light bulb.
a pc power supply fan is brushless, with only two wires coming out to switch off & on.
not a practical suggestion by any means even if u could find a brushless fan big enuf, but there ya go.
