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Picture of How to build an electric bike for less than $100
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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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Step 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)

Step 2: Tools/Materials

This step is very critical. If you do not have the tools or materials listed, I strongly advise against undergoing this project. And I speak from experience.
Tools:
Lathe (this is mandatory)
welder
basic hand tools (hacksaw, pliers, etc.)
dial caliper (if you don't have one, buy it. and don't skimp, get one with a depth gauge)
drill press with many bits
chain breaker
freewheel remover
grinder
metal cutting tools (piranha is very nice, but a plasma cutter or oxy torch will also work)
basic bike tools
optional tools that you might need:
v-blocks
surface grinder
mill
tap and die

Materials: (other than the obvious)
angle iron
*9-tooth, ANSI number 40 machinable hub sprocket from McMaster, part # 6793k208
2 bearings from McMaster, size to be determined later
steel round stock (depends, between .5 and 1 in D)
*4 inch diameter v-belt pulley from Chicago die cast pulleys
*1 inch diameter v-belt pulley (I machined this one, but it would be much easier to just buy it.)
V-belt
*note that these sizes may change depending on your bike and top speed requirements.

Step 3: Obtain materials

This is probably going to be the most challenging step of all. There are three main components that you will need to find for free in order to do this thing for under $100 like me. You will need to find a motor, batteries and a bike. Let us start with the bike. It is very easy to find a bike for either free or very cheap. Just make sure that when you are looking, you try to find a bike with as many gears as possible. This will give you either a higher top speed or better acceleration. (Yes, gears are mandatory for this project, as it gives you more tolerance when it comes to the chain drive) Try Craigslist, or if you have family that lives on a farm like me, you might just be able to ask them if they have a spare one lying around. You could also just use the bike you already have, or if all else fails go to the dump or a scrap yard (just make sure it is legal first). However, be careful. If the bike has been setting outside for a while, you will probably need to do some maintenance and a general tune up . Finding a free bike is probably the easiest part. Now in the next stop you can kill two birds with one stone. Odds are your dad probably does not repair power chairs like mine does, but I would guess you will have some sort of medical supply store around where you live (this is not a hospital, but they are often affiliated). Once you find a medical supply store around were you live, go and ask to talk to a service technician. Explain to them what you are doing, and odds are that they will either give you a motor and possibly batteries or contact you when they get one in. My dad is a service technician and they get in old batteries and motors in all the time that they just throw out, and I have quite the stash of free electric motors and seven 12v power chair batteries, all free. This is by far the best place to go, but if you are turned down maybe try a scrap yard or dump for a motor you could scrounge. (Again, make sure it is legal) If you have family that lives in the country, talk to them. They usually have lots of junk lying around that you could get a motor out of.

Step 4: Machine your bearing cups

Picture of Machine your bearing cups
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The bike I picked out already had threaded bearing cups, so I got lucky. However, if you did not get lucky, you will have to machine your cups. I would recommend machining something that looks a lot like what I have, accept not threaded, and held into the Bottom bracket using set screws.

Step 5: Machine the jackshaft

Picture of Machine the jackshaft
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Since every bike is different, you will have to design and machine your own parts, but the jackshaft should be very generic. Assuming you bought a large pulley, bearings and sprocket with 1/2 diameter center holes, you will need to start with a 5/8 inch D piece of steel round stock. Machine about an inch of one end to 1/2 diameter. Then you will need to measure how far it is between your 2 bearings in the bearing cup, and leave that to 5/8 D. then turn the last few inches of your piece to 1/2 D. leaving the 5/8 in the center will keep the jackshaft from sliding back and forth. Next, you will need to drill your own holes for pins. I would recommend using v-blocks to hold the jackshaft while you drill the holes. It is very important that these holes line up perfectly. The size of pin you use is up to you, and depends on the size of shaft, etc.

Step 6: Modify your sprocket

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If you ordered the same sprocket as I did, then the sprocket will be way too wide for your bike chain. This will require you to machine the sprocket. Chuck it up in your lathe with a facing tool and face away until the sprocket is .10 inches wide. Then set your compound rest to 10 degrees and machine the angle on the tooth so that it matches the other side.

Step 7: Main drive Pulley

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Since the odds of you obtaining a motor exactly like mine are very slim, so this will be just a guide as to how I machined mine. Since my motor already had a center pinhole, I bored the inside of a piece of 1 inch D aluminum round stock to the exact size needed to fit over the shaft. This is VERY VERY important that this hole is ABSOULUTLEY NOT oversized. If it is you will have to re-do the part. Then I drilled the pinhole, and machined one end down to .5 inch D to fit the pulley that I had to Machine, but you could probably just buy one. (I realized afterward that the size of the pulley that it said was the outside diameter, not the inside, which is what I thought it was)

Step 8: Begin assembly: jackshaft

This is the most exciting part! The bike finally gets to start coming together. Go to the hardware store and buy your roll pins and set screws, and, well, start assembling! This will take a little troubleshooting on your part, but if you machined everything correctly then it should all fit together.

Step 9: Assemble chain drive

This is where you will need your chain breaker tool. You should have already broken the chain to take it off of the bike. Now you will set the chain up like normal, going correctly through the rear derailleur and meshing on to the middle sprocket on your rear cassette. Make sure that the rear derailleur is in the right position to ride, and not all bunched up or on the wrong gear. Next, lay your two chain ends side by side so that you can get close to the correct length of the chain. This is the hardest part. Next, you will break the chain in that link, making sure that the links you break will mesh. Note: when breaking the chain, be sure to leave the pin STILL ATACHED TO THE SIDE OF THE CHAIN! If you do not do this, it will be very difficult if not impossible to get the chain back together.

Step 10: First no load test

This is where you will need to test your craftsmanship. Nothing would be more disheartening than finishing you brand new electric bike, going for your first test run when... It throws the chain. This test is very important. The bike should be upside down to allow the rear wheel to spin freely, and the bike may be in whatever gear you want, but I would suggest the lowest. Now is the tricky part. With one hand, hold the motor firmly down against the v-belt to provide tension. With the other hand, connect the motor wires to the battery. If everything was machined correctly and accurately, then this test should go fine. If it did not and threw the chain, there could be a number of problems. One that I ran into was my jackshaft sprocket was too wide, so I had to file it down a little bit. If your belt is slipping, either you have a way to high gear ratio or you are not putting enough tension on the v-belt. If it keeps throwing the chain, your sprockets are probably not lined up perfect and will have to re-machine some parts.

Step 11: Mock up your motor mount

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Next, you will need to make a cardboard mock-up of your motor mount, for a few reasons: cardboard is cheaper than metal, you can cut it with a knife, and you can shape it much easier than metal. If you bike will allow it, I would suggest mounting the motor behind the seat post like me, so that it will give you more room for batteries and keep the motor (and most of the spinning parts) out of the way of your legs.

Step 12: Motor mount- rough cut

Picture of Motor mount- rough cut
Next, you will need to use your cardboard mock-ups to lay out the design on to a piece of sheet metal. Lay the cardboard on the sheet metal, and trace it as accurately as you can with a piece of sharpened soapstone. Then you will need to cut out the mount. This is where it is VERY VERY nice to have a piranha. If you do not know what that is, it is just a giant pair of hydraulic scissors that cut metal. It makes very clean, precise cuts and is excellent for cutting the outline of your mount. However, if you don't have one of these, then a plasma cutter is the next best thing, however when cutting through sheet metal this thick, there is going to be quite a bit of slag, and if your not very good at it there will be quite a bit of grinding to do at the end to clean it up. Of course, you could also use an oxy-acetylene torch or a hacksaw, but both of those are not very good options.

Step 13: Motor mount- bolt races step A

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This is the most crucial part of your motor mount. These are the races for the bolts of the L-bracket (if you have one) and U bolts so that they can slide up and down on the main plate. Since you already have you cardboard mock-ups, the layout of these are very easy. Just lay the mockup out on the plate and center punch the two ends of each race. Then you will need to drill out holes of each end, so you will have four holes. Make sure that the holes are just the right size, not so big that the nut will not seat correctly, but not so small that the bolt cannot fit through. Since I used 3/8 inch bolts, I dug through the drill bit box until I found one that was as close to .4 that I could find.

Step 14: Motor mount- bolt races step B

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Now you will need to cut the races. For this step, I considered using the mill, but decided against it for a lot of reasons. However, I would strongly suggest milling out the races if you have the proper sized end mill and the correct sized vise. However, I chose to cut out the races with a plasma cutter. Using a piece of angle iron as a guide to make a straight cut, plasma cut out the races for your bolts. Mine did not look to pretty after this, and yours probably will not either, so there will be A LOT of grinding in order. It is very important that these races are as clean as possible so that the bolts will be able to slide easily and lock down tight.

Step 15: Motor mount- L bracket

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Note: This step is optional, and depends on your motor. I made an L bracket for my motor mount, but did not have enough clearance from the rear tire to use it. If possible, I recomend an L bracket to give your motor more support, but if it is not possible, then simply using U bolts will do.

Next you will need sort of an adapter bracket that will attach to your motor and slide up and down the main mounting plate to provide belt tension. Make a plate that will bolt on to the front of your motor and hang off to the side a little. Then take a small rectangle that will run parallel with your motor and bolt on to the main mounting plate.

Step 16: Weld on the motor mount

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Now, after extensive sandblasting and a little time with a wire brush we are ready to weld! Make sure that your joints are clean and free of rust, paint, dirt, etc. Now since you are welding two different thicknesses of metal, this long weld is going to be particularly challenging. However, if you burn through it is not the end of the world. When you are running this bead, try not to weld the whole thing at once. Weld on one side, and then move to the other to allow the metal to cool. Also, try to direct most of your heat onto the mounting plate, and use the lowest amount of heat possible and still get good penetration. If necessary, you could even run a very small bead accompanied by a much larger, hotter one to attach the 2 pieces of metal. Finally, I would use a MIG welder, as stick would burn through way to easily, and I am not very good at TIG welding.

Step 17: Assemble belt drive

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This step is self-explanatory. Slip the v belt over both pulleys, pull it as tight as you possibly can, and then tighten down all of your bolts. One thing that you may notice is that your belt will stretch with use. This is the main reason why we did an adjustable mount. You will need to regularly check your belt tension during use and adjust as necessary.

Step 18: Second no-load test

Now is the time to do a second no-load test, which will test both your motor mount and gears. Put the bike in lowest gear, and start running the motor at full rpm. If the mount holds (and it should) then gradually start shifting up to the highest gear. If you added a speedometer, note the speeds that it is reading (unless you mounted it on the front wheel) and note any belt slippage. This could indicate either a loose belt or a gear ratio WAY to high.

Step 19: Battery mount

Next is the battery mount. I hope that you got a good set of batteries from the medical supply store, but if you did not then you will just have to buy some. Make sure to get a matched pair and a good charger for them. Next, make some cardboard mock-ups of the batteries. It is much easier to move around a hollow cardboard box than it is two 30-pound batteries. Once you have made your mock-ups, find a good place to mount them. You will want them mounted as far back and as low as possible, to give your rear wheel more traction and lower your center of gravity. After you have found a good place to mount them, construct a "tray" of sorts out of angle iron, so that the batteries can be set in and held securely with zip ties or bungee cords. Then just simply weld the trays to the frame of the bike. These welds need to be strong, as they will be supporting a lot of weight, so the more support you can give them the better.

Step 20: Wire up the motor

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By now, some of you are probably wondering, "Where is the motor control?" Well, there is not one, at least not a PWM controller anyway. Since you picked out a bike with gears, all you need for your motor control is a simple switch. I got a 10-amp single pole triple throw switch from radio shack. It has three different positions: on1 off and on2. This will allow me to have on1 be 12v as in the schematic, and on2 be 24, also shown in the schematic. The two different speeds will allow me to run the motor at either full or half RPM. These two different motor speeds and the different gears should give you a wide range of cruising speeds, thus eliminating the need for a very expensive PWM controller.
Note: there are two options for wiring the motor: The 3 battery and the two battery. Each has there own advantages and disadvantages. Picture 1 is wiring option 1: the three battery. Picture 2 is wiring option 2: 2 battery. The 2-battery option is the one I am using and the one I would recommend.

Step 21: Maiden voyage and troubleshooting

This is by far the best step of all! Now that you have finally finished your brand new electric bike, it is time to show it off. Call over all of your friends, throw a party, and take the maiden voyage of your new green vehicle! Do not forget safety gear, especially on the first test! If something goes wrong (and it probably will), you do not want to get your brains spilled out all over the asphalt. In addition, you should be prepared for a failure. It is highly probable that your bike may not work. Lots of things can happen, from a minor wire disconnection to a major gear ratio miscalculation. It is best to do this test where you will have access to tools to fix any problems when they arise. Now when you run into a problem, there are a few simple ways to detect it, provided in the table below:

bike is not moving:
Disconnected wire
Gear ratio to high
Dead batteries
to diagnose this problem, pick up the rear wheel and turn it on again. If the tire spins, then your gear ratio is way too high. Try making the jackshaft pulley larger, or the motor pulley smaller. Both of these will decrease your gear ratio and give you more torque so you can move. If the tire does not spin, this could mean either disconnected wires or dead batteries. Charge your batteries and check them with the voltmeter. They should be outputting around 26 to 27 volts at a full charge. Also, check your continuity with a voltmeter. Disconnect the wire leads going to the motor and reconnect them to the leads of your multimeter. Turn the switch on, and if you get a reading of zero then you have a complete circuit and the problem is with your batteries.

Bike goes to slow:
Wrong gear ratio
to diagnose this problem, pick up your rear wheel again. If it spins much faster than what you were going, then your gear ratio is too high, and will need to be fixed by either increasing the size of the jackshaft pulley or decreasing the size of your motor pulley. If the tire spins just as fast as you were going without load, then you can increase your gear ratio by either decreasing the size of your jackshaft pulley or increasing the size of your motor pulley.

Step 22: Extras

This step is for those of you that are wanting a little more, but are also willing to go over the $100 dollar budget. You may have noticed that, in order to keep this project in budget, I have eliminated a speed controller. This is not necessary for my project, because all of the gears will give you a wide range of speeds. However, a speed controller would defiantly be beneficial. I have heard that alltrax makes a good one.

You could also add lights and turn signals to the bike, but that is a whole instructable in itself.
easy
a little more complex
Just amazing!
turn signals

You could also give the bike a custom paint job

You could also use an epilog laser cutter to cut out decals and stickers for your bike.
An Epilog laser cutter would be totally awesome. If I won one of them, There are numerous things I could do, from cutting out accurate templates to custom engraving all of my projects. If I won an Epilog zing 16 laser cutter, The instructables community can expect many more amazing instructables from me!

Step 23: Math

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Yes, there is a lot of math involved in the construction of an electric bike, so here is what I used and a few formulas that should help you out.
First off, gear ratio calculator. This formula will give you top speed under no load, so be sure to compensate a little bit for load.
((R((pi*A)/ (pi*B)))(C/D)(pi*E))*.000946969697 where R is rpm of motor, A is diameter of motor pulley, B is diameter of Jackshaft pulley, C is teeth on jackshaft sprocket, and D is teeth on the rear sprocket (if your bike has gears, use the smallest for top speed, largest for slowest speed.) and E is the diameter of your rear wheel.

Next is figuring out the 5/8 inch length of jackshaft. Assuming the outer face of your bearing cups are the largest dimension of your bottom bracket, insert them and take a measurement with your caliper. Mine measured 2.817 in. Then remove the bearing cups, and insert the bearings with the cups farthest edge laying flat on a table or other hard surface. Then use the depth gauge on the caliper to measure from the inner edge of the bearing down to the table. Do this with both cups. I got the measurements of .591 and .595.
Then add those 2 together, and subtract them from your largest dimension to get your 5/8 inch length of jackshaft. I got 1.631 for mine.

Figuring out the size of your bearings is very easy, and does not really require math at all. Just take an ID measurement of your cups and purchase a bearing as close to that outer size as possible, and as wide as possible, and preferable with a .5 in center hole. To be more Accurate if you are machining your cups anyway, you might as well purchase the bearings and then machine the cups to fit them.
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etrikebikes4 years ago
Whoa my young friend,

I applaud your ingenuity, get up and go, and skills, but if I were grading this project I would start from C and go down from there, on the basis of your design goals. You simply cannot put all that extra weight including 2 honkin' lead acid batteries on a cheap bike frame and go 40 mph without frightful safety concerns. Even the Federal e-bike limit of 20 mph is too fast for this project. Limit it to 12-15 mph and you will be infinitely safer and go at least 4 times as far on a charge. Then you'd start with an A in my book.

Making your own personal electric transportation for $100 is not worth heavy duty injury or your life, and that is just what you risk.
It's a good thing you are not grading him then. While safety is a concern, it's not as much as most people think.
The federal limit is bullcrap, I can pedal faster than that, the government wants to hold your hand for everything.
The fact is he is being graded on his skills, ingenuity and ability to critical think, not to where a safety harness and ask the government to hold his hand ffs this is why we are in such economic debt.
hardcore,

You might feel comfortable promoting dangerous activity by yourself and your neighbors for the sake of an ultra-libertarian ideology, but I'm not. The federal limits for an e-powered bike to stay within the confines of an unlicensed, uninsured vehicle, that is still considered a bicycle, are quite reasonable, which is why most states are now following them. The European limits are about 30% more stringent, so count us lucky.

I don't have a car anymore. For the last 3 & a half years my personal transport (around Chicago) has been an e-trike that is Federal and state legal. Even at the lowly 20mph I'm on average as fast as automobiles around town except for the expressways, which often aren't very express. It cost me about 10 times this project to put together new from kit, making my own battery packs, using barely more than $50 worth of hand tools. I don't have to fear hundreds of dollars of fines for going illegal and that extra cost was long ago amortized out. See us in action at www.etrikebikes.com, ,"E-bike Shopping in Winter."

This was a fabulous garage project for perhaps the track, and Mechanical Engineer should be applauded on that basis. It's not appropriate to the street because so much weight on such a slight frame would be close to uncontrollable in emergency at federal limits and downright crazy at twice federal speed limits for e-bikes. The federal nanny is doing a good job! I prefer her to an early grave which is possible enough to get when mixing it up with 2 ton SUVs or worse..
Boo
I think I will build one with the power chair motor and bicycle. No lectures about safety- I already have titanium in my spine. I will take responsibilty for my own safety. I've also got a Honda 750 motorcycle engine I plan to put on a regular go kart. That ought to be fun!!!
Regarding your comments "much weight on such a slight frame would be close to uncontrollable in emergency" and "twice federal speed limits for e-bikes".

Regarding weight and control, I have a similar weight engine assembly on a similar bicycle and there are no control problems. So in my experience this bicycle should have no control problems. Regarding the legality of this bicycle, there are more powerful ebikes sold in stores and the stores aren't getting busted. So I don't think this is an illegal bicycle design. Normal bicycles break federal bicycle speed limits, it's also illegal to flick boogers into the wind in Alabama, America has a lot of unenforced laws on the books. I think it's unlikely police would have a litigious hissy fit over this bike.

Well said, mate.

lucek4 months ago

Was looking at this but when I did found out that my state considers this a moped and thus requires registration and drivers licence(I have none. Reason I was looking at electric bikes).

JeevaB5 months ago

Hi, My friend which size bearing you used?

allan.moffat8 months ago

The plastic pipe held on by sticky tape for use as a foot rest looks UNSAFE ! , may I suggest using a pair of stunt pegs on the front axle ?

Then you will be able to steer this bike using your feet whilst reading the morning paper on the way to work.

Hey by any chance, do you know what the output for the motor you used was?

as far as horsepower or wattage, I do not. I just kinda took what I could get. All I know is that it is a 24 volt electric powerchair motor. If I had to take a wild guess, I'd say around 300-500 watts.

mohd_owais1 year ago

hi .. guys .. actually I have a project of my exam and I need to build an electric bicycle . so if any of u who know how to do it plzz .. can u help me out .. I need the instruction for building the electric bicycle ..

I give this project an A+ because I would pay $150 - $300 for a kit like this, batteries not included. The only thing I would want done differently for a kit would be for the connection to the center frame to use u-bolts, maybe with holes in the plate for different size frames.
dddddd4 years ago
Yes, a hundred dollars in parts,
but over a thousand dollars in tools.

It often turns out like that.

I could do it without "a thousand dollars in tools".

* 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.
Welding is stronger than brazing no? Going 40 mph top speed i'd like to know it's as strong as possible.
No, it's not a strength issue. Both welding and brazing are very strong and both methods result in a seam that is usually stronger then the surrounding metal. But each method has advantages and disadvantages depending on what you are making. Some metals like aluminum are difficult to weld but easy to braze. Brazing can be more expensive depending on how much work needs to be done. One of the main differences in what method you should use is size of the metal piece you are fixing. Large metal pieces are hard to braze because it's hard to maintain the right temperature range for brazing, but would be easy to weld. So for example, if you're fixing a 7 inch brass propeller, gear, engine casing, aluminum kickstand, with stuff like that brazing will work great. But if you're fixing a huge anchor, the hull of a ship, a steel car frame or engine block, in those cases regular welding equipment would be the best technique to use. http://news.thomasnet.com/IMT/2005/01/18/welding_vs_braz/ Anyway, I love this instructable. But the battery holders and motor mount could definitely be made without a welder.
Ah thank you for clarity in your post. I had actually seen brazing that is just as strong if not stronger than welding however did not know the requirements to make such a strong joint.
Another thing, if you used a smaller motor support plate and moved the location of that motor plate you could use u-bolts for mounting that motor plate to the bicycle frame. They sell pulleys for attaching to bicycles so the pulley adjustment doesn't have to be on the motor support plate. I have a friction motor bicycle and the engine is connected above the back wheel to the frame with just bolts and there are a lot of motor bicycles out there that use pulleys. Here's a picture of friction motor mounted above the back wheel. http://i00.i.aliimg.com/photo/v1/763275826/Rear_Friction_bicycle_motor_kit.jpg Also however you connect things, I'd suggest using superglue or lock-tight compound so the nuts don't loosen up from vibration. To further reduce welding requirements, Bicycle saddle bags or side baskets might be an easier way to store the batteries then making custom holders. There are plenty of DIY projects out there if you want plans to make bicycle saddle bags.
lol Right on !
when i saw the rest of his pictures, I find yes, it is :0)
You are 100% right.
BtheBike dddddd4 years ago
plenty of local tool co-op kitchens all over . one can also 'wardrobe' tools, which is : buy , use , return .

Where da pedals at? =/
Thats what hackerspaces are for!
Here in Texas you can't do this. It can be an assisted device- the pedals have been removed therefore it becomes a motor driven vehicle. Instead do what I did- http://www.fiveflagsmotorbikes.com/ElectricBicycleMotors.htm It's less than 450.00 and IT REALLY REALLY WORKS! I've got mine up to 12 gear and 45MPH! Takes three hours to recharge with a range of 20 miles un-assisted (no pedallling) and up to 35 miles assisted @ 10mph. Uses three deep cell 12 volt batteries. Been using it since 2008 with no problems.
Interesting enough the top speed for e-bikes in the US is 20 something miles p h. So while you say you "Can't" do this your doing something you're advocating to do something your not supposed to do anyways.
i think that pedal rule it prolific in the U.S. to be considered a 'bicycle' . Hub motors are great ,yes. I really think though that more research should be done with the 'chain drive' design like this. It takes advantage of the gears
thanks for the input- I got mad at $4.00 gasoline and wanted to do something about it. It's actually faster on my bike than riding in my car to my 9 mile communte. With the hub I can get to work in as little as 15 minutes- I use bike paths and back streets with little traffic. the one thing that really helps are KEVLAR TIRES they have saved me from falls several times. Regards, M
Ha! yes I have a bionx hub kit . actually beat friends from a-to-b more than a few times. One friend was impressed enough to buy his own last year. it has gotten me in good enough shape to commute by single speed bmx .

How have the kevlar tires kept you upright ? You mean from having a blowout? 1 Thing i've used is tire liners . This way ,one can reuse it with any cheap tire.
I once beat an ambulance with it's siren wailing across the 59th street bridge between Queens and Manhattan, without power assist. Of course that says more about rush hour traffic across the 59th Street Bridge than anything else.
Wow I use to live in Little Ferry NJ! Great Stuff Thanks.
yep , rush hour is 1 thing that inhibits cars. Then you have traffic lights , stop signs , cross walks,sidewalks, grass, dirt, curbs, one way streets , school zones , etc... . I knew of 1 friend who got a speeding warning on a human powered bike going 40 downhill in a 25mph zone but this is super rare .

My a-to-b example was during Non-rush hour . I sweat very little to beat cars home but I would have sweat a lot more without assist.

Wow great stuff. Here in houston we have lots of pot holes uneven roads, wierd expansion joints in the roads and sidewalks. So if I was using regular tires- either a blow out or bent wheel
MyRide.JPG
i've used kelar with the additional tire liner too . With the 2 in concert , I've never gotten a puncture in over 1000 miles ,But I have pinched the tube a few times . With the economy some roadways are going unrepaired , personally i usually pop tubes on curbs .

I like your (Crystalyte?) rig . Steel and sturdy . Not likely to get ripped off =) .
You get it going over 35 + mph on flat roads ?! Thats awesome. Bionx peaks at
25 mph but I'm more than happy with it.

you see this ?http://www.youtube.com/watch?v=jmPUze3WBTw&
ABSOLUTLEY A W E S O M E! I I use to race motorcycles when I was a teenager- Feel The Need For Speed! I like to see the looks on recumberant cyclists when I pass them like they're standing still- very fun they just can't figure it out. Great stuff thanks!
eeglinton2 years ago
As a Major priority you should ditch the standard caliper brakes with rubber blocks and scrounge a pair of disc brakes. You are aiming for road speeds close to your national open road limit.
In addition normal bike helmets just don't cut it at these speeds get and use a full face motorcycle lid.
This is good advice. I really don't think he'll be doing 40mph consistently, just because he has the top speed to do so.
mlt342 years ago
This certainly is a cheap eBike build. For anyone that wants a higher quality ebike though, I recommend building one yourself using the guide at www.UltimateEbikeEbook.com since I found it so helpful.
Could you post an instructable? Will it cost us over a 100$ with over 1000$ in tools?
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