A large radiator fan motor would be a better propositon than the starter motor or alternator .

I had thought of that, as well, but I wasn't sure if it would be powerful enough. What are the specifications of a radiator fan motor?

 

I had thought of that, as well, but I wasn't sure if it would be powerful enough. What are the specifications of a radiator fan motor?

That's going to depend on the model of car. The radiator fan motor in my nissan sentra is about the same size as a cordless drill motor.

cordless drill motor

thats an idea.

I have seen a cordless drill used before to drive a razor scooter; 2 of them might power a bike nicely - or not

 

That's going to depend on the model of car. The radiator fan motor in my nissan sentra is about the same size as a cordless drill motor.

cordless drill motor

thats an idea.

I have seen a cordless drill used before to drive a razor scooter; 2 of them might power a bike nicely - or not

I have various cordless drill motors, but none of them are powerful enough. I also read once about someone who used two cordless drills to power the two rear wheels of a go-cart, but they were 36v drills, which are very expensive (for me )

 

Man I have been thinking about this and I think the simplest way would be to use your starter motor and PWM. Just put a low value power resistor in series with the starter. Figure that the starter will be almost a direct short at zero speed so use a 1Ω resistor for a 12A limit or a 2Ω for 6A limit and so on. If you find that it doesn't have enough balls, then add an encoder or something for speed detection, connected to a μC (or other circuit) and once it's at speed, have a relay short out the current limiting resistor.

 

Man I have been thinking about this and I think the simplest way would be to use your starter motor and PWM. Just put a low value power resistor in series with the starter. Figure that the starter will be almost a direct short at zero speed so use a 1Ω resistor for a 12A limit or a 2Ω for 6A limit and so on. If you find that it doesn't have enough balls, then add an encoder or something for speed detection, connected to a μC (or other circuit) and once it's at speed, have a relay short out the current limiting resistor.

This is a good suggestion. I will be using a microcontroller for the PWM anyway, so I may be able to use part of it for a speed detector. I will definitely look into it!

UPDATE: I found someone who is willing to give me an old generator from a VW Super Beetle. All it needs is a set of brushes, which will only cost a few dollars. Definitely worth it, IMO. What do you all think?

 

this page says it's a 30A 12V generator. I'm not sure how the rating work when it's used as a motor; may draw 30A or maybe more, IDK.

If it's free, go for it! A lot simpler than trying to convert an alternator.

 

Strantor I already told you starter draws 40 A no load and remember all plain beardings ...so where does all this 6A stuff come from ....rad fan motor about 10 A at 12 v for a big one about 4 in dia and 3 in thick

 

Yes I remeber you saying 40 amp for a starter. I dont remember you saying which starter. I imagine a geo metro starter would draw significantly less amps than a chevy silverado 3500 starter. The 6A is what you would get is you dropped 12v across a 2ohm power resistor. Reread my post, it was pretty clear.
Who was talking about running a starter with no load anyways?

 

I love this kind of ideas. I have a retired go-kart sitting at the back of my house which I hope to eventually convert to electric. I plan on using motors and drives from "real" EV parts though, but I certainly have googled starter motor options for projects earlier:

Go-kart
http://www.youtube.com/watch?v=C5lp3fP1WKo

Bike
http://www.youtube.com/watch?v=x8cJ1GNiHOI

Looks like lots of fun!

 

I love this kind of ideas. I have a retired go-kart sitting at the back of my house which I hope to eventually convert to electric. I plan on using motors and drives from "real" EV parts though, but I certainly have googled starter motor options for projects earlier:

Go-kart
http://www.youtube.com/watch?v=C5lp3fP1WKo

Bike
http://www.youtube.com/watch?v=x8cJ1GNiHOI

Looks like lots of fun!

Wow, that second one is almost exactly what I would like to do! The only difference is that I would still like to be able to pedal the bike sometimes. Also, I can't seem to figure out where they put the batteries, and what type they were...?

EDIT: Well guys, I'm thinking of just taking off the pedals of my bike to make room for other parts. I guess I'll be powering it just by motor. Otherwise, I wouldn't have room for anything else. Just thought I'd let you all know

 

Wow, that second one is almost exactly what I would like to do! The only difference is that I would still like to be able to pedal the bike sometimes. Also, I can't seem to figure out where they put the batteries, and what type they were...?

EDIT: Well guys, I'm thinking of just taking off the pedals of my bike to make room for other parts. I guess I'll be powering it just by motor. Otherwise, I wouldn't have room for anything else. Just thought I'd let you all know

Have you seen this? http://www.ecospeed.com/emddet.html May give some ideas as to doing what you want to keep the pedals.

One way of putting power into the pedal crank and not having the pedals turn is one of these;http://www.bocabearings.com/bearing-types/one-way-bearings This is the same thing used inside the rear wheel sprocket.

Some more information; http://www.electric-bikes.com/bikes/kits.html
While your doing your own thing, the information may give ideas of other things -ways to do things.

 

Well, I think I'll just go without the pedals on this one. The reason is this: I have a set of 6 "stacked" sprockets from an old 18-speed bike wheel that I plan to mount on the shaft of the motor. If I power the rear wheel directly with that, the ratios will be way off--it would probably have too much speed and too little torque. For that reason, I plan to have 3 sets of sprockets. The first, of course, is the one on the motor shaft. I will run a chain between the motor and the sprockets that the pedals used to turn. Since these are much larger, I should get the right ratio there. Then, I will leave the original chain between the "pedal sprockets" and the rear wheel. This way I may even be able to shift when the motor is running--I'll have to do a bit of experimenting first

Anyway, I think the pros of removing the pedals outweigh the cons. I would get more space for things, such as the motor and the battery, and it will also help with the gear ratio. Also, I would not need to worry about the pedals coming back and grinding my legs to a pulp

I'm getting a pretty good idea of what I want to do, so keep those suggestions coming--they're helping a lot!
Thanks everyone!

 

oops! I think you'd better keep those pedals on. Once you remove the pedals that contraption falls under the classification of a motorcycle, with all the registration, licensing and insurance requirements.

 

oops! I think you'd better keep those pedals on. Once you remove the pedals that contraption falls under the classification of a motorcycle, with all the registration, licensing and insurance requirements.

Yikes, I guess I should look into the laws in my state. I never thought of that...

I was thinking I had heard somewhere that in Vermont, it classified as a motorcycle if it had a gas motor over 50 CCs or something. Like I said, I'll have to look that up. I might just make some "dummy pedals" that just sit there and don't turn--that wouldn't be too hard
Anyway, thanks for pointing that out.

UPDATE: I just looked it up and I found the following dates and actions:

[The bill] States that, for purposes of Federal motor vehicle safety standards, a low-speed electric bicycle as defined by CPSA shall not be considered to be a motor vehicle within the ambit of Federal transportation law.

2/27/2001 Introduced in House
3/5/2001 Reported by the Committee on Energy and Commerce. H. Rept. 107-5.
3/6/2001 Passed/agreed to in House: On motion to suspend the rules and pass the bill Agreed to by the Yeas and Nays: (2/3 required): 401 - 1 (Roll no. 27).
11/18/2002 Senate Committee on Commerce, Science, and Transportation discharged by Unanimous Consent.
11/18/2002 Passed/agreed to in Senate: Passed Senate without amendment by Unanimous Consent.
11/18/2002 Cleared for White House.
11/22/2002 Presented to President.
12/4/2002 Signed by President.
12/4/2002 Became Public Law No: 107-319

I see nothing about the absence of pedals written here, so I think I'm okay. I will keep looking though, just to make sure.

EDIT: Just did some more research and found the following:

CPSC rules stipulate that low speed electric bicycles[24] (to include two and three wheel vehicles) are exempt from classification as motor vehicles providing they have fully operable pedals, an electric motor of less than 750W (1 hp), and a top motor-powered speed of less than 20 miles per hour (32 km/h) when operated by a rider weighing 170 pounds.

So, Mr. Chips, You are right, and I can't make "dummy pedals" like I suggested. I guess I'll have to work out some other way of setting this up. Thank you very much for mentioning this--I could have gotten in a lot of trouble

 

Since you can't control the torque on a starter motor as mentioned earlier, can you get your hands on a weed whacker or chain saw motor? I think a strong blender motor might even be of use...

I'm curious to see how this turns out

 

Starter motors are designed for intermittent duty and very high torque at very low speed and, while they could probably be useable for an electric bike, would be far from optimum.

You can buy motors specifically designed for electric bikes and go-carts at salvage or surplus stores. I think they sell in the $30 or so range. Two sources where I have seen many of these motors are All Electronics in Van Nuys, CA (888-826-5432, www.allelectronics.com) or Apex Surplus Electronics in Sun Valley, CA (818-767-7202, www.apexelectronic.com). Shipping should not be too much because these motors are only a few pounds, but you may find some at surplus electronics outlets closer to VT. All Electronics also carried some simple electronic controllers just for these motors at one time. The motors I've seen come in two power ratings, but I don't remember what the ratings were.

awright

 

Since you can't control the torque on a starter motor as mentioned earlier, can you get your hands on a weed whacker or chain saw motor? I think a strong blender motor might even be of use...

I'm curious to see how this turns out

I had an old 12 volt weed whacker and I took the motor out of it. Unfortunately, it's really small and would not even begin to move the bike. I can hold onto the shaft and it wouldn't move!

Starter motors are designed for intermittent duty and very high torque at very low speed and, while they could probably be useable for an electric bike, would be far from optimum.

You can buy motors specifically designed for electric bikes and go-carts at salvage or surplus stores. I think they sell in the $30 or so range. Two sources where I have seen many of these motors are All Electronics in Van Nuys, CA (888-826-5432, www.allelectronics.com) or Apex Surplus Electronics in Sun Valley, CA (818-767-7202, www.apexelectronic.com). Shipping should not be too much because these motors are only a few pounds, but you may find some at surplus electronics outlets closer to VT. All Electronics also carried some simple electronic controllers just for these motors at one time. The motors I've seen come in two power ratings, but I don't remember what the ratings were.

awright

I suppose you did not get a chance to read all four pages of this thread? This idea that you mentioned is something that is being discussed. I have seen several videos of bicycles with starter motors on youtube. I think it will be fine for what I plan to use it for.
I also mentioned using a generator, as well. Someone has already offered to give me one, so that's what I'm going to plan on using for now. Any suggestions related to this are very much appreciated!

 

Well, guys, I had another idea. Instead of going without pedals, I thought of another way to have both. The pedals are easily removable on my bike, so I am thinking of just taking off the pedals when I want to use the motor. Then, when I want to pedal, I can just put them back on. Easy, right? Any opinions or suggestions?
Thanks!
Der Strom

 

Well, guys, I had another idea. Instead of going without pedals, I thought of another way to have both. The pedals are easily removable on my bike, so I am thinking of just taking off the pedals when I want to use the motor. Then, when I want to pedal, I can just put them back on. Easy, right? Any opinions or suggestions?
Thanks!
Der Strom

there's a reason they don't make locking hubcaps on 4X4 trucks anymore. they're not as convenient as they seem

 

there's a reason they don't make locking hubcaps on 4X4 trucks anymore. they're not as convenient as they seem

Um... Are you agreeing or disagreeing with my idea?