Yes, it is actually possible to build an electric bike for under $100. The secret to doing this is... get most of your materials for free! Now I am not just going to turn you lose and say go find this stuff either. There are a few tricks and tips that I will give you and places to look. In addition, you will need to have problem solving skills of your own, since everything you get will probably be a little different from what I have. Undertaking this project is going to be challenging, and if you do not have substantial knowledge of machining tools, you might as well back out now. However, if you know your way around a lathe and are handy with only a few simple tools, this project is something you can complete in a few months working in only your spare time. This is also my entry into the Epilog Laser Cutter challenge, so please do not forget to rate and vote! Also, if you have any suggestions on things I can add to make this better, PLEASE comment, as I will be handing this in for a very important grade (basically my whole 4th quarter grade) so any criticism and help would be greatly appreciated! Thanks!
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Signing UpStep 1: Background and Theory
Before we dive into the instructions, I will need to give you a little background on this project. As a senior in High school, we are required to do a "senior project" that includes writing and presenting a research paper over a topic of your choosing. Included in this research paper must be an observation, or an essay about a hands-on experience you had regarding your topic. The requirements are simple: the topic must be school appropriate and you must show both foreknowledge and a significant learning stretch. Electric bike conversion was the perfect topic for me, because I have already successfully built a friction drive electric bike, but my previous attempts with chain drives have failed, so obviously I had to come up with a plan to successfully build this thing, so first I took a look at where my first attempt was unsuccessful, and it was pretty obvious. My first attempt at building a motorbike found me not paying attention to tolerances. I was just guessing when sprockets aligned and welding them onto what looked like the center of the shaft! Ouch! There was no way that was going to work. In addition, the shaft on my motor was very small, and trying to attach a sprocket to that would not have worked anyway. Therefore, I needed a way to drive the rear wheel (using the standard rear cassette) from the motor. My solution was a belt drive. So then, I wondered how to convert the belt drive to a chain drive to drive the rear wheel. The answer to that was a (not so simple) jackshaft that will mount in the bottom bracket perfectly aligning the drive sprocket and the driven sprockets. To make this project work I also knew that there would be no more welding on of sprockets, so instead I opted for a much more accurate (and better anyway) pinning method. In addition, my first bike, with a measly top speed of 20 MPH, left quite a bit to be desired. Therefore, I wrote a formula to calculate gear ratios, and decided to gear my bike for a top speed of 40 MPH! Finally, I had to find a way to get all of these parts with very tight tolerances. To answer this question: I simply had to machine them, and machine them very accurately. Accuracy is the key to being able to make this project work. Without a metal lathe, this project would be impossible to pull off. Now, with enough background information, it is time to continue to my senior project: convert a normal bike to a powerful electric motorcycle! (For under $100)
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In addition normal bike helmets just don't cut it at these speeds get and use a full face motorcycle lid.
However, one good place to check for motors would be any local golf cart shop that does repairs. Picked up a rebuilt motor for less than scrap value.
Alternating and Direct current are both deadly and neither is really "safer". Any current above .8 of an Amp is deadly. Edison tried to show the public that A/C is deadlier by electrocuting an Elephant named Topsy because he wanted people to use Direct Current in their houses. He used the execution as a way to promote DC scaring people into believing that they can be executed by the AC in their homes.
I cant believe you newbies think you know so much,.. Just look at ANY multispeed bicycle chain drive system and you will see the huge misalignment as it shifts thru the 5-7 gears at the rear... How can you say there can be no missalignment in a chain system ???? . I guess 10,0000000 bike owners are wrong? And you must be correct..
I built riding cars trikes bikes when you were just a glint in your papas eyeballs. I didnt use a lathe either. Everyone is telling you hand tools will sufice and auctually give a better bike. I didnt tell you this because you are obviously a child and I didnt want to be harsh...But I see you kknow it all . We feel confort from those who agree with us but we learn from those who dont.
blower motor
I have a ligier ambra in good shape and was thinking it could be a good project to converted to electric do you think the variator would work ok with elect motor would one large motor be ok, you mentioned Lynch motors what o/p kva do you think would do the job assuming the present gearing is used also i guess you would not have to pay any more road tax. hope you can advise thanks
But, HUGE props on your project! I just bought two older power wheel chairs I want to do this with (oh, if I had the time....)...
Way to go!!
http://www.zafr.com/trucktcom/parallel_sw.htm
You can also see the general idea of a series/parallel toggle (Although this one is placing motors instead of batteries in series/parallel:
http://www.instructables.com/id/SIMPLE-ParallelSeries-Select-Switch/
In step 7 it looks like the motor shaft is protruding very little from the can so it seems like there is therefore not much material actually interfacing with the 'main drive pulley'. Could this be a potential problem once you tension up your belt and are transmitting a fair bit of force? Did you think about taking the motor apart and machining your own (longer) shaft?
Step 17: could you have saved a bit of weight on that mount – it looks a bit oversized for the amount of variance you are going to get with due to the belt stretching. Looks a bit like it might poke you in the leg while riding to?
Step 19, Battery mount: Nicely done, I like the use of the cardboard mock ups. Will they get in the way of your legs a bit though?
Apart from that, how did you get on with actually riding it?? It would be cool to hear about your riding experience here. I find that when I ride a conventional bike I need to stand up from time to time to relieve ‘seat to bum fatigue’ – without pedals or an obvious place to put your feet how do you get on?
Anyway, thanks for sharing and happy riding.
In step 7 the small shaft is a problem, as also is the very oddball size (.472" Diamater) so right now I am in the procces of re-disighning the mount. You can see in step 15 that I have included instructions for an L bracket, even though i didn't use it. to solve the main drive pulley problem, I will be flipping the L bracket around, adding another support to make it a u bracket, and cutting a channel for the shaft to go through. I have extended my motor adapter from 2 inches to 4 inches, so that it can be supported on the other end from a bearing. As soon as I finish this I will udate the instructable. Also in the motor mount of step 17, I used 1/4 inch sheet metal, so it is not very heavy. I was also trying to make it as sturdy as possible, and the trade-off of half a pound for the extra strength was one I was willing to take. as it is behind the seat post it is also well out of the way of my legs. As far as the battery mount in step 19, it is a problem. The battery mount is the only part of the bike that I don't like. They make mounting and dissmounting a serious problem, and an extra 100 lbs at the very top of the bike make it very unstable and a pain in the but to use. The only problem is im not sure where else I could mount them. As far as the foot pegs, Im working on that too. In the main pic you can see my temporary foot peg in the form of pvc pipe bolted to the cup holder mount. The riding experience is great though, aside from the high center of gravity. The tourque is a little bit low, but it's pretty fast and really fun to ride. Thanks for your comment!
im out at the lathe....
but over a thousand dollars in tools.
It often turns out like that.
* I would would do any welding using brazing instead which would cost me less then $30 for all new brazing tools from the store.
* I would use fiber added to clay and (zinc or aluminum) for casting any parts. A propane torch + two tuna cans + pliers + zinc + clay + (cotton balls or flour to prevent clay cracking) and all that would be less then $30.
* Motors often have brass fittings on the shaft. I would either braze onto that or melt zinc to connect the pully to the motor. Or I would use the brazing to build a socket for the motor if the shaft was contained iron (which would be removable). Any of these methods would be low temperature enough to not damage the motor.
* And if I needed a lathe I just rig one using my drill, possibly using wax and then casting the part as above. A drill, coat hanger wire and wax would all cost less then $20.
I think that you're right, the author did not think much about how to control tool costs. But with a little planning, I believe this project could be done for 10% of what you think the tool cost are.