Ghetto EMB

Fol67

New Member
Aug 5, 2008
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I am trying to make a dirt cheap Electric Motor Bike, so far my choose of equipment is
Bicycle Frame: Junkyard - Free
Motor: Large Box Fan - $5.00(Used. Thrift Store)
Power: Two Rechargeable Car Batteries - $20.00 est.

I plan to use direct friction and use a lead stick with a clip attached to it as a speed controller, and a simple house light switch(stripped of course) for a kill switch. Both easily obtained for under a dollar. What do you think? Any suggestions?
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
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north carolina
Well now I have done those from using very basics to trying the whole controler throttle bit.

One was no better than the other. I used a house type switch as an on off switch and powered the bike full throttle or off and let it slow down by itself. It worked just as well as the throttle and controller for me. I did not find any significant improvement in battery life with the controller at all. I was expecting to but I didn't.

I have three of four scooter motors laying around as they were the best for for me. Friction drive is the easiest for sure. I have used sla batteries and lawn and garden tractor batteries. They both worked about the same except the wet cell lawn and garden batteries are very heavy and any extra energy in them goes to lugging them around. I made several trailers for that purpose.

I wired my switch directly to the battery and motor. Simple motor on motor off kind of thing.

Good luck.
 

wolverine

New Member
Jul 29, 2008
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Re: Cheap EMB

I'm not an engineer,but I really don't think you can get enough torque out of that fan motor.
Plus you need to boost 12v to 118v for power and 118v in the rain might make your hair stand up. But hey,prove me wrong,I'd like to see it. Maybe try an old electric trolling motor, torque and voltage would be solved. Just need to get enough cooling for the motor. If you build it ,I got to see it.Good luck.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
If you have to buy a motor go for a scooter motor of at least 350 watts. I done been down that road. Anything less and the power to do hills is just not there. Unless of course you weigh 75 pounds.
 

jasonh

New Member
Jun 23, 2008
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Longmont, CO
Yeah I doubt that fan will give you enough torque to get moving.

Starter motors from cars work wonders. There's a youtube video of some guys that used a starter and a car battery and had enough torque to pop wheelies from a dead stop. Just a thought :)
 

eDJ

Member
Jul 8, 2008
530
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Wayne National Forest
A friend of mine had this old go cart with a fried engine given to him. It was a nice cart and anyone else would have put another motor on it. This guys dad was an industrial electrician and he modified a car starter of some kind and used a big pickup truck battery for the enegry cell. He rigged a rheosat to the throttle pedal and had a master disconnect in the circut such as in the case of emergency the power could be shut off completely.

It was fast and quiet. I still remember his grand dad lubing the motor bushings with Slick 50 as the starter motor wasn't really designed for constant use. Had the starter motor had bearings in it, then it could really have been a piece of work. I wish I knew how his dad wired it all up.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
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up north now
A box fan is AC, not DC.
A starter could be fun in bursts, but as stated it will not last when run continuously.
 

Tj Bunch

New Member
Jun 18, 2008
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Look up bar stool racing, The old 6Volt starter motors is what they used to use for them. And they would get up and goooooooooo. There was a muffler shop here in Fresno that the guy would build them and they had races, This was in the 80's and I was only like 19 but still fun to watch now i'm OAS (old and slow).
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
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pampa texas
You could use a drop cord but your range will be limited. rotfl
I couldn't help it I thought that was funny. rotfl
 

comfortableshoes

New Member
Jul 22, 2008
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Beverly, MA USA
what about getting a used Black and decker rechargeable 24v lawn mower- that should have enough torque and guts for a MB. I saw one on Craigslist for $75. I have one I use for my lawn, but I eye it thinking a electric bike might be fun, but I know I would not live another day if I used my very expensive rechargeable lawnmower for a bike- my SO would cut my fingers off so I couldn't dismantle any more lawn equipment. Every time I bring home a weedwhacker there is a hopeful gleam in the eyes that perhaps this one will survive and actually be used on the lawn. I don't want to hold a 2 stroke next to my ear- the best place is next to my rear on my bikes tire!
 

Dan

Staff
Staff member
May 25, 2008
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Moosylvania
"I don't want to hold a 2 stroke next to my ear- the best place is next to my rear on my bikes tire!"

That could be the start of a country song, lol
 

sojudave

New Member
Oct 18, 2008
189
2
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austin tx
ah good point. You'd need a motor to drive the motor. But the alternator is wired to..no it's not. Battery to starter, starter to crank, crank spins belt, belt spins alternator, alternator generates current to power vehicle.
 

Dan

Staff
Staff member
May 25, 2008
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Moosylvania
Thats what is awesome about you folks. The way thoughts and ideas meander in to really great ideas. Have to run, (wifes battery died) but will enjoy pondering this some more!

Thanks, some incredible stuff.