How to make an electric bicycle with your own hands from scrap materials - step-by-step instructions. How to make an electric bike from a regular bike? Making an electric bike

How to make an electric bike from a regular bike?

Hello, friends!

On this page I I’ll tell you how to convert an ordinary bicycle with your own hands into an electric bicycle, equipped with an electric motor and moving not only due to the muscular strength of the rider, but also on electric power.

It all started when I once took apart an old washing machine"Indesit" and extracted many useful spare parts from it, including an electric motor and belt drive parts. In addition, I had a bicycle, already slightly modified (the seat was moved back a little using an insert into the frame to make it more comfortable to sit), but otherwise the most ordinary :

First we had to figure out how to transfer the torque from the electric motor to the wheel from the bicycle. Since the electric motor shaft already had a pulley for a belt drive, and a good belt remained from the washing machine, it was decided to use just such a drive - a belt drive. Now you need to figure out how to secure the belt pulley to the bicycle wheel (obviously, the rear one).

The bushing is aluminum and cannot be welded, so it was decided to secure the pulley to the wheel hub using several screws. Notice the new holes in the hub between the spokes (pictured below). There are only 9 holes, they have M3 threads:

Now you need to make the pulley itself. Generally speaking, the belt from a washing machine is poly-V-ribbed, but since the pulley we are going to make is much larger in diameter than the pulley on the electric motor shaft, there is no need to cut grooves on the large pulley - the belt should not slide on it anyway. Therefore, our wheel pulley will be smooth.

To make it, I cut a circle from 2 mm thick sheet steel, in which, among other things, I cut out large holes to reduce weight. The diameter of the pulley in my case was limited by the lathe I had (you simply cannot insert a workpiece of a larger diameter into the machine) and was approximately 220mm.

A steel strip (standard rolled steel) with a cross-section of 20 x 4 mm was welded to the outer side of the resulting disk. The part in the center of the future pulley (pictured below), bolted, is only necessary to secure the pulley on a lathe during processing (this is some part from the transmission of a Niva car).

After welding, the pulley was turned on a lathe. The outer surface became smooth.

Next is painting, drying and installation on the bicycle wheel. During final installation, all parts (the wheel hub, the center mounting hole of our pulley and nine M3 screws) were lubricated with epoxy glue" Poxipol " - so that it holds more securely and does not become loose during operation:

When trying to install the wheel and pulley into the bicycle frame, it turned out that the new pulley was a little in the way and rested against the frame tube. It was decided to bend the frame a little:

Now it was necessary to somehow secure the electric motor. Since the bicycle is equipped with a rear shock absorber, it was necessary to attach the electric motor to that small part of the frame that is rigidly connected to the wheel (to ensure constant belt tension). Besides,It is necessary to provide a mechanism for tensioning our belt.

To understand which position of the engine is most optimal, first it was fixed in the right place relative to the bicycle using boards and ropes, after which the wheel was rotated to make sure that the belt did not tend to move off our homemade pulley (after all, our pulley has no grooves, nor any edges):

Then the dimensions were measured, the parts were cut out from thin-walled steel tubes and directly in this form (while the bicycle and the motor were connected to each other) they were welded (tacked) to the bicycle frame. After this, the engine was untied, the boards were removed, and the parts were finally welded:

Painting again, drying...

The belt tensioning mechanism was made from parts from a thing for tensioning cables (the so-called “lanyard”). This thing has two screws - one with a “left” thread, the other with a “right” thread, as well as a special central part - a nut with similar threads on both sides. This central part was cut with a grinder, and its threaded ends were welded to the ends of a thin-walled tube of the required length. The screws themselves were welded on one side - to the motor mounting stud, and on the other hand - to a special platform with a hole, put on the axle of the rear wheel of the bicycle. The result is a mechanism with a tube (red in the photo below), which, when rotated, can raise or lower the motor, which leads to either tension or loosening of the belt. To fix the tube in the desired position from below, it is secured with a lock nut:

Now it was necessary to select the type and number of batteries. Since our electric motor is from a washing machine, which is powered by a 220V AC network, this means that the motor itself is designed to operate on a maximum of 220V (AC). Maximum, because in a washing machine the motor speed is regulated over a wide range by changing the voltage on the electric motor, and the motor develops maximum modes only at the end of the spin cycle.

But batteries provide direct current, not alternating current. However, this works to our advantage, since AC commutator motors also work well on DC. Moreover, such motors work even better at direct current, since the inductive reactances of the motor cease to play a role. As a result, I settled on a voltage of 96V (8 twelve-volt batteries), and after looking at what was available in the store, I chose batteries with a capacity of 5Ah:

To secure these batteries to the bike, I decided to make a separate box in which I would place the batteries and the necessary electronics:

When the box was ready, it turned out that... there was no room for it! It was planned to mark it on the frame, in the place where the gas tank is located on motorcycles, but it became obvious that it would be impossible to sit on the saddle of a bicycle (there was nowhere to put your legs):

Therefore, I began to look for an opportunity to attach this box to another place, for example at the back, but it turned out there was nothing to attach it to at the back (you can’t attach it to the motor, because the heavy box will not be “sprung”, and it is impossible to attach it to the saddle post - the motor is in the way ):

But there seems to be room in the front, and something to attach to:

Therefore, this is where I welded it:

Again painting, drying, installing batteries, connecting them in series and securing them:

And here it is, the long-awaited moment - the first tests, so far without any electronics, the engine is connected to the batteries directly, using a machine in the box and a switch (toggle switch) on the steering wheel. To measure the operating current, a multimeter was attached to the bicycle:

Tests have shown that the design is quite functional "in terms of the engine", but the heavy box in front of the bicycle makes it very difficult to control (the steering wheel is difficult to control), and there is no question of driving onto any curb without getting off the bicycle, to drag him into the elevator (there is no freight elevator in my house) requires a lot of shamanic actions, accompanied by untranslatable sayings, and the temporary switch on the steering wheel completely burned out due to fire and prolonged burning of an electric arc in it when it was turned off (opened).

It became obvious that the heavy box in front of the bicycle had to be disposed of. Therefore, it was cut off and the batteries were placed evenly on the frame, each separately. In addition, car horns (horns) were provided, as well as mounts for control buttons for these horns on the steering wheel. Due to the numerous welding points for attaching the battery pads, the frame had to be repainted almost entirely.

Tests again, this time much more successful. Handling was good again, and getting the bike into the lift (with the front wheel raised) became much easier. Since there were no electronics yet, I didn’t even try to start on electric power from a standstill - I was afraid of burning the engine or breaking the belt. I turned on the automatic power supply only after accelerating on the pedals to a speed of at least 10...15 km/h. At the same time, a current of about 10A began to flow through the engine, which decreased to 3...4A as it accelerated.

At first I wanted to make an electronic unit that was supposed to ensure not only the operation of the engine from the batteries, but also the charging of the batteries from the engine in braking mode. In addition, there should be a sufficiently powerful 12V converter to power the horns (beeps), and also, preferably, a charger so that you can charge the batteries anywhere without worrying about forgetting to take a “charger” with you.

However, plans are plans, but in practice, in this form, this bike stood with me for more than six months - I still didn’t get around to it.

Then I decided to make electronics for control, but in the simplest version - only an engine power regulator, without any energy recovery during braking, without a built-in charger and even without 12V for the horns - they were simply removed.

The task of such an electronics unit is to transmit the required power to the engine, proportional to the position of the throttle handle. In addition, so that the current cannot exceed the limit values ​​when starting off at full throttle, when the current reaches this limit value, the power is limited and no further increase in the current occurs. As acceleration progresses, the current drops, and the power limitation is removed - it becomes the same as set by the throttle.

Also, the tasks of the unit include monitoring the degree of discharge of the batteries and preventing their deep discharge (voltage drop of less than 9V per battery (less than 72V for all). That is, if the voltage drops on all batteries to 72V, the electric motor will be turned off - you will have to continue driving on the pedals.

The motor controller is made in the form of a pulse step-down converter operating at a conversion frequency of 32.5 kHz. Here is his diagram (click to enlarge):

The control signal is “generated” by the “throttle”, made in the form of a conventional variable resistor near the right steering wheel grip:

This signal is sent to the input of the microcontroller ADCATtiny26 companiesAtmel . The other input of the ADC of this microcontroller receives voltage from a current shunt (measuring resistor), made in the form of a printed conductor on the board, through which the full current of the traction motor passes (slightly to the left of the center of the board in the photo below):

Changing the engine power is achieved by changing the duty cycle of the PWM signal (Pulse Width Modulated signal) supplied to the gates of power field-effect transistorsIRFB33N15D via driver chipIR2127S. The manufacturer of these power transistors and driver chips for them is the company International Rectifier. Total power transistors IRFB33N15D three pieces, they are connected in parallel - to reduce the voltage drop across them and increase the efficiency of the converter.

It all works as follows. At the moment when from the microcontroller through the driverIR2127S to the gates of transistors IRFB33N15D a control pulse arrives, they open, and the electric motor is connected to the battery. However, since the motor itself has inductive reactance, the current through it cannot increase abruptly to prohibitive values ​​- it begins to “slowly” grow. After some time, the control pulse from the microcontroller disappears and the transistors close. However, thanks to the self-induction EMF, the current through the motor does not stop abruptly - it finds its way through three parallel-connected diodes10CTQ150 the same company International Rectifier and "slowly" decreases. Since control pulses from the microcontroller occur quite often (with a frequency of 32,500 times per second), the current through the motor does not have time to change significantly during the pulse or pause between pulses, and is maintained at a certain average value. The wider the pulses and the narrower the pauses between them, the greater the average current flows through the engine, the more the bicycle “rushes to hit the road.” In turn, the pulse width is maintained by the microcontroller program proportional to the throttle position, but the program also ensures that the current through the motor (voltage on the current shunt) does not exceed the limit value (7A).

The microcontroller is powered from a voltage of 5V, produced from the battery voltage by “charging” from a mobile phone Sony Ericsson K750i . As a result of the experiment, it turned out that this “charging” can operate in a very wide range of input voltages - not only from a 220V network, but also starting from 12V(!) DC and higher. In our system, the voltage on the batteries varies in the range of 70...120V, which is quite suitable for this “charging”.

However, in our circuit there is also a driverIR2127S , which requires 12...16V power. This power is produced from the 5V voltage by tripling it with the circuit section in the lower left corner (see diagram). To the gates of transistors IRLMS ...pulses are supplied from the microcontroller with a frequency of also 32.5 kHz, but with a constant filling of 50% (square), which cause these transistors to switch and recharge the capacitors to the right.

The driver itselfIR2127S consists of two parts - low-voltage (the terminals on the left according to the diagram) and high-voltage (the terminals on the right according to the diagram). The high voltage part needs a separate power supply, not connected to the power supply of the low voltage part. This power source is made in the form of a ready-made modular DC-DC converter with galvanic isolation P6AU-1215ELF.

In addition, the driver IR2127S also carries protective functions - it monitors instantaneous current through power transistors IRFB33N15D , and if it rises to emergency values ​​(much more than 7A) (for example, in the event of a short circuit in the motor), it will immediately turn off the power transistors, preventing damage to the circuit.

Another input of the microcontroller’s ADC is supplied with voltage from the battery. The microcontroller program provides five battery voltage thresholds, ranging from “battery is fully charged” to “battery is completely discharged”. These states are indicated by two LEDs, red and green. When the voltage on the batteries decreases to 72V (9V per battery), the microcontroller goes to the “battery is completely discharged” state, and the control signal is no longer supplied to the gates of the power transistors - power is not transmitted to the engine - you will have to continue pedaling.

Structurally, the electronic unit is mounted on two printed circuit boards - power and low-current:

The boards are housed in a semi-hermetic plastic case, power transistors and diodes are routed to a radiator at the bottom of the case. During subsequent “home” tests, and then during long trips at full throttle, no noticeable heating of this radiator (to the touch) was noted - it is possible that it was possible to do without it.

You can see how to use the electric bike you received in the video below:

Just during the days of writing this article, I was lucky enough to find another washing machine, this time "ElectroLux"When disassembling it, it turned out that the motor in it is designed for greater power than used on an electric bicycle, and therefore has less internal resistance - less losses. This means that such a motor will allow you to go either faster or further. As a result, the motor on the electric bicycle was replaced with a newly found one. Since the “new” engine had a longer shaft, it had to be installed offset with a slight modification of the mounting system:

Already with this “new” engine, tests were carried out for travel range and maximum speed.

Tests for travel distance on one battery charging was carried out in two stages.

1. Almost uniform movement at low speed. Conditions: the road was mostly dirt, in some places it was asphalt, the traffic was in a ring (in a circle). The length of the circle is approximately 2 km. The road as a whole is almost horizontal, but in some places there were slight descents and ascents. When moving, the pedals were rotated without much effort. The gear ratio (meaning the position of the chain on the sprockets) is maximum - 3 on the front sprocket and 7 on the rear. In climbing sections, the force on the pedals was applied more noticeably - to help the engine. The position of the “throttle” was approximately in the middle, and did not change during the test (it was constant). The average speed is approximately 17 km/h. The weight of the rider including clothes (my weight) is about 100 kg. Under these conditions, one battery charge was enough for approximately 25km.

2. Driving at higher speeds in a real situation. Conditions: the road is mostly asphalted, but the asphalt has numerous cracks and breaks, and in some places the road is unpaved. There are quite frequent small descents and ascents. When moving, the pedals were rotated with medium effort. The gear ratio is maximum - 3 on the front sprocket and 7 on the rear. The position of the “throttle” varied from approximately average to maximum, depending on the situation on the road; numerous accelerations were made at “full gas”, as well as prolonged movements at “full gas”. The average speed is approximately 25...30 km/h. The weight of the rider including clothes (my weight) is about 100 kg. Under these conditions, one battery charge was enough for approximately 17km.

Top speed tests were carried out under the following conditions: speed was measured using GPS navigator. The road is asphalted, flat, horizontal. The batteries are “fresh”, the pedals have not been rotated, the throttle is in the “full throttle” position, the rider’s weight including clothes (my weight) - about 100kg. Under these conditions, the speed of steady motion was 30km/h. During prolonged movement uphill with a slight slope, other things being equal, the speed drops to 25 km/h.

It should be noted here that the electric motor used is a commutator motor, and is connected according to a series excitation circuit. With this scheme, the engine develops maximum torque at the moment when it is stopped (i.e. at the start). As you accelerate, the torque quickly decreases, and with a further increase in speed it tends to zero. However, such a motor does not provide any resistance to movement, no matter how high its rotation speed is (of course, not taking into account the friction in the bearings and on the commutator brushes) (unlike three-phase motors with an electronic controller - which are installed in factory motors -wheels for electric bicycles - they have a certain maximum rotation speed, at which they switch to generator mode and prevent further increase in speed). Therefore, in our case, with additional rotation of the pedals it is possible to achieve significantly higher speeds than with electric power alone. Thus, under the same conditions as in the maximum speed tests, but withBy applying maximum effort on the pedals, with the chain mechanism set to maximum gear 3/7, we managed to reach a speed of 42 km/h.

Thank you for visiting this page!

Many people like bicycles for their comfort and the ability to exercise. They are used as a means of transportation in urban areas with difficult traffic. But not everyone wants to spend energy to reach the desired location.

Often the speed of a conventional device is not enough. Then ideas are born on how to create an electric bicycle from available materials so that it meets the requirements of environmental friendliness and is more functional. The fact is that purchasing a factory version is not affordable for everyone.

What are its advantages?

First of all, it is considered a mobile device for movement, since it can pass through the narrowest places of the road. And he is not afraid of traffic jams of varying complexity.

Let's consider all the advantages:

• Will be an excellent alternative to using public transport;
• An electric bicycle can be operated without the need to obtain a license;
• It does not need gasoline, however, the electrical voltage controller will have to be charged frequently;
• Helps you maintain physical fitness.

To decide that you need this type of transport, pay attention to the photos of homemade electric bicycles of various configurations.

They may differ in design features and functional characteristics: weight, available speed, driving range on a single charge.

How to create one yourself?

First of all, let’s figure out what you need to assemble an electric bicycle yourself. It is very important to find a functional bike that can withstand heavy loads. A lightweight model will not work - it must be a strong specimen.

But the most important thing is to purchase an engine with sufficient power. In addition, you will need the following list of additional elements:

• Controller based programmability;
• Two mechanical disc brakes;
• Acid type batteries;
• Set of fuses and switches;
• “Star” based on 66 and 123 teeth;
• Stainless steel fasteners for secure engine installation.

But this is not enough, because without the necessary tools it is difficult to secure all the parts.

How to collect?

Step-by-step assembly of an electric bicycle with your own hands is carried out. It is necessary to modify the brakes and the front fork, then move on to the rear. After this, the following are connected to the bicycle: the engine, the battery and the resistor - this happens in turn.

The diagram of the simplest finished model should include:

• Reliable body from the regular version of the bicycle;
• Efficient engine;
• Power supply;
• Battery;
• Correct version of variable resistor;
• A chain similar to a moped version.

You can create many different circuits based on the same battery. But speed and functionality may vary. To correctly create a reliable option, you need to have knowledge from the field of physics. We are talking about Ohm's law, the possibilities of electrical conductivity of materials and strength of materials.

But the regular version is simple and easy to create yourself. During the assembly process, you can notice some shortcomings and eliminate them or identify a way to modify the electric bicycle.

Engine

Thinking about how to make an electric bicycle yourself, everyone comes to one thing - you need a reliable engine. In order for it to work efficiently, it is necessary to ensure that the voltage and current match.

If the model has a power of 400 W, then, taking into account a reliable gearbox, you can reach a speed of about 30 km/h. And, if you install a capacious battery, then the range can reach 30 kilometers.

Important: Do not forget about the balance between the battery capacity and its voltage, the capacity and voltage of the unit. For an engine with a power of 500 W, you will have to install a 12 V battery with 40 amperes/hour. In other words, rely on Ohm’s law and then the electric bicycle circuit will last longer.

Note!

What controller is needed and how to set the resistor?

The controller changes the traction level of the electric bike. And this is what primarily distinguishes it from the regular version. This device helps to optimally distribute traction to all wheels and ensure smooth operation of the unit.

For this version, throttle grips are required. Using a variable resistor, it is easy to regulate the speed and speed of the engine.

After calculating the required energy level, the opening contacts are mounted on the brake handle (in closed form). By pressing the contacts, the circuit will open or close, and the motor will slow down or speed up accordingly.

Conclusion

Now you have simple instructions on how to assemble an electric bicycle yourself. It remains to advise not to overstress the battery by increasing the maximum speed of the unit.

Keep your bike away from direct sunlight as the battery capacity will noticeably decrease due to overheating. We recommend accelerating with your muscles to save precious energy.

Photos of electric bicycles with your own hands

Note!

Note!

Today we will talk about how to assemble or make an electric bicycle with your own hands at home. We will also learn how to convert a simple mountain bike into an electric bike using an electric wheel – photos and instructions

Even an electric bike assembled with your own hands on the basis of the simplest bicycle has a small engine that successfully pushes it forward. We can say that this is the least powerful, but still a transport. Depending on the motor power provided by the manufacturer, which ranges from 150 to 1000 W, an electric bicycle can make pedaling a little easier for unprepared riders, or even take on the entire load. True, the speed of movement of a bicycle with a motor, in comparison with a regular one, did not increase much. The reason for this is the traffic rules that divide all vehicles into categories.

Although, of course, there are craftsmen who create homemade electric bicycles with more powerful motors, using them to reach speeds of up to 120 km/h and even climb hills without using their legs. By the way, assembling an electric bicycle with your own hands is no less popular (or even more) than factory-made ones. For those who are at least a little technically savvy, there are even special kits that include the basic components for equipping a simple city two-wheeler: the engine itself, a battery and charger for it, as well as a control controller.

Detailed video on assembling an electric bicycle from a motor-wheel kit:

A significant advantage of an electric bicycle, regardless of assembly (do-it-yourself or factory-made), is that charging its battery will not be difficult for those who have a regular power outlet nearby. Just like a mobile phone, a bicycle can be left to charge overnight; a few hours will be enough for it to be ready for “work” again in the morning. What if the battery dies on the road? It's okay, by pedaling the old fashioned way, you can get to your destination. Types of electric drive for bicycles. It doesn’t matter: you assemble the bike in a factory or do it yourself at home using ready-made kits such as the “Electric Bike Conversion Kit”. The main part that facilitates the movement of such bicycles without human effort is, of course, the electric drive. And there are several types.

The most common and recognized by numerous users for its silent operation is the built-in motor. This is the case when the motor is attached either to the front or rear, or to both wheels of the bicycle at once, without spoiling the appearance of the vehicle, but only noticeably making it heavier. A wheel with a motor is good because it has a power of 150-1000 W and does not require large expenses for installing equipment. An electric drive with a chain is noisier, but less heavy, and also practical, since many self-taught craftsmen have learned to use motors from any household electrical appliances to create their own electric bike.

The power of such an electric drive and the possibility of using a gearbox make its operation efficient and its driving quite fast. The only pity is that the cost of finished components is higher than that of the first type of motor. The friction electric drive roller of a bicycle is attractive only in its installation: there is no need to disassemble the entire structure. It is installed on top of the wheel. As the roller rotates, it transmits torque to the tire, causing the wheel to move. The friction electric drive has a large number of disadvantages in relation to other types of motors. The efficiency of such an engine is much lower than others, and the high cost and rapid wear of tires make it an unattractive option for buyers. In addition, for the system to function normally, you need to constantly monitor the pressure in the bicycle tires, and this is not very convenient.

The advantage of this kit is that you can easily convert a regular bicycle into a bicycle with an electric motor using these components. All you have to do is install and connect this electronic set for full operation. Let's take a closer look at the electronic kit and what is necessary for the operation of an electric bicycle:

1. The simplest thing is that your bike with different wheel diameters is taken as a basis - 20, 24, 26 or 28 inches.

2. Electric bicycle wheel - is a brushless electric motor for a DC bicycle, which is spoked into the rim. It can be installed either front or rear, or to both wheels at once - all-wheel drive. In terms of power, electric motors for a bicycle can be as follows - 250 W, 380 W, 500 W and the most powerful wheel motor is 1000w (for example, 500 W can reach speeds of up to 45 km/h, which is no small amount). This bicycle motor does not require adjustments, settings or maintenance.

3. Battery – The battery is the second most important part. Performs the function of supplying current from the battery to the electric motor. Batteries come in 12, 24, 36 and 48 volts. Although, the higher the battery power, this does not mean that the speed will increase. It is recommended to select the battery according to the voltage of the electric motor. Buy LiFePO4 batteries (lithium phosphate batteries), as they have the following advantages - cheap, reliable, durable (on average 1500 charge-discharge cycles), charge quickly (about 2-3 hours). The charger for such batteries is quite simple and in most cases resembles a charger for mobile phones.

4. Special handlebar handles (speed controller) – allow you to adjust the speed of the electric bike.

5. Controller - a block with various wires, which is responsible for the operation of the entire electronic mechanism. It is a board that is housed in an aluminum case to protect it from external influences. The best place for it is the flask holder.

6. Battery case or bag – designed for storing batteries.

7. Various wires and fuses - for the operation of the above items. You can also use regular wires from audio speakers.

Advantages of a homemade electric bicycle:

1. If you use a ready-made wheel motor kit, you can install it on your bike in just a few hours.

2. The price of electric motors for bicycles will be significantly lower than buying a ready-made, assembled electric bicycle;

3. The finished electric bike will be much heavier due to standard parts and the simplest batteries; .

4. The finished electric bicycle will have low power, since if you want to assemble the electric bicycle yourself, you will be able to select the components you are interested in individually.

We have given just a few arguments that will help you with your choice, but in order to independently assemble and invent a working mechanism, you need to understand electronics.

The main difference between an electric bicycle and a regular bicycle is the presence of a motor, batteries and a controller. In the end, I would like to conclude that the impressions from such an electric bike can only be positive

A do-it-yourself electric bike kit consists of an already assembled wheel, a controller, a gas handle, brake handles, a pedal sensor, a headlight with a lock, a horn button, and a bag for the battery.

The second part of the kit is the battery and charger.

The kits come in 12, 24, 36 and 48 volts and 250, 380, 500 and 1000 watts.
The battery is selected with the appropriate voltage. I would advise not to chase power. 380W is sufficient for flat and hilly terrain. By increasing the power, the speed will not increase significantly, but it will be better to “pull” uphill.
My personal experience is that I very rarely help with the pedals and the sprockets are always in the “maximum speed” position.

It is worth noting that in many countries there is a limit of 250W.
Why I chose 48V, I can’t say for sure now, but in May, when I was combing the Internet before purchasing, a mark was placed - take only 48V. With battery power, everything is simple - I have 10A, that’s 25 km. If you buy 20A, there will be 50 km of range and 16 kg of battery instead of 8. Decide whether it's worth carrying around the extra 4-8 kg of weight if you don't plan to travel far. I understand that power is not measured in amperes, but this is how sellers differentiate them. Not watt/hour, but voltage/amps.

Motor for a homemade electric bicycle

Wheel-motor 4. already assembled. Tire and tube not included. The wheel must be chosen according to the size of the wheels of your bicycle; for me it was number 26 - the most common size. If you bought a tube or tire, you know the size for sure.

The main thing to remember when mounting the wheel is that the cable must come out of the wheel on the left! Then it will rotate in the right direction. The second and not obvious danger is that three thick wires and several thin ones come out of the wheel. The first thing a person does after mounting a wheel is to spin it. The wheel generates electricity, a spark jumps between the power wire and one of the thin wires and that’s it, the sensor burns out, the rides are cancelled. Therefore, having taken the wheel out of the box, we immediately wrap these wires with electrical tape and hold them like that until they are connected to the controller.

You may have to slightly sharpen the seat on the fork and the axle on the wheel, this is what happened to me. A Dremel and a few cutting discs were enough to install the wheel.
Here you need to be as careful as possible; the tighter the wheel fits into place, the fewer problems there will be in the future. Don't waste too much. Owners of expensive bicycles with aluminum forks should choose a rear wheel; I read how a powerful kilowatt wheel simply broke off the whiskers on the fork during a test drive. The front fork is designed to pull up and back, while the wheel pulls forward and around. But the motor on the rear wheel puts loads on the frame no different from the pedals.

Electric bike controller

The controller is a small aluminum box 3. with a bundle of wires. There are no special problems with it. Find a convenient place on the frame and secure it. I luckily had two bolts on the lower beam simply screwed into the frame. I hung the controller on one of them, the second one didn’t match and I fixed it with a plastic strip. It is worth stocking up on them; they are an indispensable thing for fixing cables. The only remark. Due to legal speed limits in some countries, there is a lock in the controller. Most often this is a wire that just needs to be disconnected. A blocked controller will not allow you to accelerate faster than 25 km/h.

First, you need to replace the brake handles. I didn't change the front brake handle. I only replaced the rear one. Why do you need to change? There is a contact in the handle that turns off the electric motor during braking.

Secondly, you need to install the throttle handle on the left side of the steering wheel. Remove the rubber handle and cut it from the inside to the required width. Let's put everything in its place.

Thirdly, you need to install a headlight. The headlight contains an “ignition switch” and a sound signal. I didn’t connect the sound signal button, I can scream anyway. But I was very pleased with the pair of keys. The key replaces the power switch, and further turning turns on the headlight. It's comfortable. You won't be able to remove the key from the headlight without turning off the bike. The bicycle is quite heavy, and the travel on the pedals is also not so easy (after all, they are at maximum and you still need to turn the motor, which in this case becomes a generator) - it will not be so easy for a thief to jump on and ride off on your bicycle. Even just rolling it in your hands. This allows you to not “stress” too much by being distracted from the bike for a few minutes and not having to fasten it with a lock every time.

LEDs, in theory, should indicate the degree of battery discharge. This may be true for lead batteries, but it doesn’t work for LiFePO4 batteries. First, the battery is fully charged, then the red LED indicates the battery is empty. In addition, these are super-light LEDs and they are simply blinding right in your face at night, and they also interfere during the day. That's why this strip of sticky paper is there. Then I grind off the tips of the LEDs and add a drop of hot melt glue on top to get just a matte glow.

Self-assembled electric bike battery

This is a type of lithium battery. LiFePO4 is cheaper than its cell phone counterparts, does not explode, delivers high currents well, charges quickly, and has up to 1500 charge-discharge cycles before a noticeable decrease in capacity begins. Such batteries appeared only a year or two ago and are still little known on the market. The Chinese themselves assemble them from individual elements of the required voltage, power and size. In addition to the battery, the bag contains a charging balancer board. A bundle of wires goes from it to the battery itself. That is, the battery is charged in parts and the individual “banks” of elements are balanced among themselves.

Why not a regular lead acid battery? A battery with the same parameters as mine will weigh more than 20 kg. There will be fuss with the electrolyte, long charging, the number of charge-discharge cycles will not be more than a thousand, but only a hundred or two. Moreover, if I go to buy such batteries in my store, it will not cost much less. So even in terms of money I won’t benefit.

The wheel motor is a brushless DC motor. Its design does not include brushes, which makes the electric machine more reliable, and several Hall sensors are installed to replace the commutator.

The excitation winding is replaced with permanent neodymium magnets, which, today, are considered one of the most powerful permanent magnets. The rotor of the structure is made of high-quality electrical steel, which increases the efficiency of the structure. The wheel motor has a stationary rotor (attached to the bike's axis) and a rotating stator. When choosing a wheel motor, you should analyze for what purposes you need an electric bicycle, and, in accordance with this, choose a product of the required power.

Electric bicycles have two main control methods: using pedals and a power control mechanism. As the name suggests, an assisted pedaling electric bike helps you pedal and requires some physical effort. With this control method, a (torque) sensor measures the speed or load to determine the required motor power. Everything is automated, so you don't have to think about anything - just get in the saddle and ride. Some e-bikes have multiple settings, while others may only have one power adjustment. You can customize the required pedaling assistance. With weak settings, the pedaling assistance will be barely noticeable, but this will help increase the operating time of the motor. With stronger settings, the power is more noticeable and you can reach very high speeds, since at the same time you will be assisted in pedaling by the motor at its full power.

On the other hand, the power adjustment mechanism does not require pedaling at all. Just like on a motorcycle, you control power and speed by twisting and holding the throttle. You can pedal in parallel, but this is not necessary.

Some e-bikes are pedal-only, others have power adjustment, and some have both. In general, assisted pedaling bikes have a variety of power settings from which to choose to suit your riding conditions, while electric bikes with both pedaling mechanisms have limited pedaling assist settings. On these bikes, full control is provided by the power adjustment mechanism (when needed) and pedal assist is of secondary importance - on flat terrain.

There are two different configurations for mounting the motor-wheel - front or rear.
Front-mounted wheel motor. Front-mount hub motors can be found on finished or converted bikes. If you are converting a standard bike, the easiest solution is to mount the motor at the front, as there will be no problems with the derailleur or chain. And since most e-bike conversion kits include rack-mounted batteries, using a hub motor up front balances the weight of the bike and improves handling.

Since there is a small risk of the front fork being destroyed by the electric motor, it is strongly recommended that the front wheel hub motor be used with a steel fork only. For finished bikes this is not a problem, since usually the motors are combined with steel forks and they are not as powerful.

Hub motors mounted on the rear wheel are common mainly on finished bicycles, since it is not difficult to install a motor at the rear at the factory. But converting a bicycle with a rear wheel motor is a little more difficult than in the case of a front hub motor, since problems arise with the chain, transmission and gear shifter. Plus you may be limited to a 6 or 7 speed freewheel. But the motor on the rear wheel provides more torque and is not as noticeable as on the front wheel. .

The battery is the most important factor affecting the overall cost of an electric bike. There are several different types of batteries available in different shapes and sizes. As a rule, ready-made electric bicycles are equipped with sealed lead-acid and lithium-ion batteries. But e-bike conversion kits also use some other types of batteries. Three main types of batteries and their subtypes that you need to know about when choosing an electric bicycle:

Sealed lead acid (SLA) batteries are the most affordable batteries, but they have the shortest lifespan and are the heaviest. Such batteries are well suited for beginners or cyclists with limited financial resources. If you decide to buy an e-bike conversion kit, you can install sealed lead-acid batteries first and replace them with more expensive ones later. For approximately every 12 V of voltage, the battery weight increases by 3.2 - 3.6 kg (x2 for 24 V, x3 for 36 V, x4 for 48 V). Lead-acid batteries are quite heavy. They are designed for 300 - 500 charges (1 - 2 years of operation). These batteries are very sensitive to the charging process and can be damaged if discharged more than 75%. In addition, by the end of the operational period their power decreases significantly.

Nickel metal hydride (NiMH) batteries are good batteries at an affordable price. They are smaller and lighter. They have a longer service life than lead-acid ones. Since most off-the-shelf electric bikes began using lead-acid and lithium-ion batteries, nickel-metal hydride batteries are only available in conversion kits that allow you to convert your bike into an electric bike yourself. NiMH batteries weigh approximately half as much as lead-acid batteries, and last 2 - 3 times longer - 400 - 600 charges (2 - 3 years of operation). Also, this type of battery does not lose power at the end of the operating period or before the final discharge.

Lithium-ion batteries (Li-Ion) have the longest lifespan and lightest weight, although they are the most expensive. Lithium-ion batteries are a general name for a large group of batteries. If you do not understand the types of lithium-ion batteries, you may get scammed in some stores or websites when sellers and manufacturers exaggerate their parameters. Types of lithium-ion batteries:
Lithium-cobalt batteries (LiCoO2) are used in laptops, mobile phones and are rarely used in electric bicycles. Very light, but unstable and unsafe. Subject to spontaneous combustion!

Lithium manganese batteries (LiMnO2) are the most common lithium batteries used in electric bicycles. The LiMnO2 battery is almost always called "lithium" or "lithium-ion". If no other specification is specified, then most likely it means a lithium-manganese battery. These are the most affordable lithium-ion batteries. And although they weigh significantly less than other types of batteries, they are the heaviest among lithium-ion ones. If anyone claims that they can withstand more than 1000 reloads, then do not believe them! This type of lithium-ion battery typically lasts 500 to 800 charges.

Lithium polymer (LiPo) batteries are slightly more expensive than lithium manganese batteries, but they have similar characteristics. They differ mainly only in design, since lithium-polymer ones do not have a hard metal shell, but only a soft polymer one.
Lithium phosphate batteries (LiFePo4) are the best lithium-ion batteries! They have the longest service life and the lightest weight among the available options! Lithium phosphate batteries are the most expensive, but they can withstand up to 1500 - 2000 charges and they have the most stable discharge schedule of all possible batteries, which means they do not lose power throughout the entire period of operation until they are completely discharged.

Battery voltage of a homemade electric bicycle.

As a rule, electric bicycles operate on voltages of 24, 36 and 48 V. As a rule, the higher the voltage, the higher the maximum speed, although this is not always the case (check the data sheet). Since power and speed can be influenced by the efficiency of the motor and transmission, a 24V e-bike may have the same top speed as a 36V e-bike. But the general rule is that higher voltage bikes are more efficient. fast. At 24 V the maximum speed can be 24 - 29 km/h, at 36 V - 26 - 32 km/h, at 48 V - 39 - 45 km/h.

Although these characteristics are outside the legal limits, some conversion kits can even be 72V and reach speeds in excess of 56km/h! But such high speeds can place significant stress on the bike's components. Keep in mind that even the fastest athletes travel on a bicycle at an average speed of only 27 - 29 km/h. 32 km/h seems like a very fast speed for most cyclists. Anything above this speed is unsafe and breaks the law. In addition, the higher the voltage, the more batteries are installed, which means the higher their price and weight.

Battery capacity of a homemade electric bicycle.

Batteries are rated by voltage (V) and ampere-hours (Ah). Voltage gets the most attention, but amp hours are just as important. Amp-hours measure the capacity of a battery. It is a good indicator of the number of kilometers that can be driven on a single battery charge. Although many other factors also have an impact: the weight of the cyclist, terrain, power consumption, efficiency, etc., but usually this distance depends on the battery capacity. So, on average, the average cyclist with a 10 Ah battery can travel 16 kilometers (without pedaling). And if the cyclist is pedaling, this number can be significantly higher, so most 10 Ah batteries are rated by manufacturers, based on pedaling, as being “capable of traveling up to 20 miles.”

Bicycles that offer assisted pedaling have a much higher power range. This is due to the fact that the cyclist is constantly assisting the engine and thereby reducing the current (power).

However, we believe that the powerful e-bike is the personal transport of the future and will continue to gain popularity. Having all the practical advantages and speed of a scooter, it is more versatile and passable, maneuverable, silent, environmentally friendly, and cheaper to operate. An electric bicycle can be stored at home; it does not require a garage or secure parking, like a motorcycle or scooter, which is dangerous to leave outside overnight.

Ecology of consumption. Motor: Total interest in electric transport has only been gaining momentum recently - people of all ages and occupations are increasingly puzzled by the question of “inventing” their own electric bicycle.

Total interest in electric transport has only been gaining momentum lately - people of all ages and occupations are increasingly puzzled by the question of “inventing” their own electric bicycle. Sometimes ideas born in hot heads turn out to be incompatible with the harsh realities of life; quite often the “Kulibino” mentality bears fruit, and the result is quite worthy of the pride of its creator.

Many manufacturers have not remained aloof from global trends, and today on the market of components for electric bicycles it is quite common to offer so-called “whale” kits for independently creating an electric bike based on an existing bicycle. In order for the bike to move without your help, you will need at a minimum an electric motor, a battery and a controller that is responsible for the correct operation of the first two units - all this, and much more, is included in the bike electrification kit. But in order for the newly-made device to be worthy of the high title of a bicycle hybrid, we suggest using the following tips.

Electric bicycle design: components and assemblies

Just as theater begins with a hanger, and dance begins with a stove, so creating an electric bicycle with your own hands begins with selecting a donor. The correct solution to this issue will depend, first of all, on the goals and objectives that the future owner of a bicycle hybrid sets for the designed vehicle.

It is best to take into account the risks of inevitable high loads in advance and use a downhill-class steel frame with a dual-suspension shock absorption system as the basis of the design. This option will be preferable to others if you are going to install a powerful wheel motor - from a kilowatt or more. A direct drive electric motor with a rated power of 1000 Watts will allow you to reach speeds of 40-55 km/h. Considering the large torque and dead weight of the engine, such a drive is installed in the rear wheel, and it would not be a bad idea to strengthen the axle mounting brackets, especially if the frame is aluminum.

When choosing a ready-made battery or creating your own battery, you must take into account parameters such as weight, dimensions, capacity and operating current. The rated operating voltage can be different (36V, 48V, or 72V) - higher voltage and higher currents will allow it to accelerate to higher speeds. If you need reliability and a long service life, choose a battery with high-capacity LiFePo4 cells. If you want to save on weight and cost, take Li-Ion. A capacity of 10 Ampere/hour is enough for about 20-40 km of travel - the amount of mileage depends on the economy of charge consumption, and for many this parameter is in no way compatible with the presence of the throttle.

When the light weight of a hybrid bicycle is more important to you and you are not chasing high speeds, the optimal choice would be a wheel motor with a rated power of 250-350W. Such engines weigh a little and, as a rule, have a built-in planetary gearbox, which contributes to the normal roll-up of the hybrid bicycle when pedaling. The “cruising” speed of low-power bicycle hybrids is in the range of 25-30 km/h. Electric motors

small power is installed in both the front and rear wheels; this does not have a significant significance, except that it is useful for a more uniform distribution of masses. For the same purpose, it is preferable to place the battery in the central part of the frame - the hybrid bicycle will have better controllability and stability. Another option for placing an electric motor - central (in the area of ​​the carriage) - has not yet become widespread in our latitudes, but many leading manufacturers of kits for electric bicycles also have such offers in their assortment.

Standard controllers in inexpensive kits are hardwired by manufacturers and do not provide for the ability to change operating parameters. If you don't need it, you can just enjoy the trip. If you want to tinker with setting up and selecting the optimal parameters for your configuration, take a set with a programmable controller like Infineon. Close attention should be paid to the switching and installation of electrical equipment - high-quality wiring designed for operation at certain currents, reliable connectors, sufficient cooling of the controller, which heats up during prolonged operation and heavy loads.

Security questions

Bicycle hybrids are a relatively new type of vehicle with a fairly wide range of capabilities. In many countries around the world, legislation equates them to bicycles if the engine power does not exceed 350-500 Watts. A more powerful electric bicycle is a different story with its own operating characteristics. Therefore, safety issues sometimes need to be given even more attention than when driving a scooter or motorcycle. Don’t forget about both protective equipment and additional equipment. Even for those who are not going to have a blast on downhill trails, but simply plan to enjoy the surrounding beauty on a leisurely ride, in any case it is worth using gloves and other protective elements that can protect the cyclist from injury in the event of an emergency.

A headlight, a tail light, additional reflectors, rear-view mirrors, a loud sound signal - all this will be useful to you on the road, and will also help other road users to notice you in time. Particular attention must be paid to the brakes - they must be of high quality and capable of stopping your hybrid bike at any time, since at high speed the usual behavior of the brakes changes. And there is no need for this to become an unpleasant surprise for you. Especially considering the increased weight of the bike, the electric drive components will “pull” an additional 12-14 kilograms. And if interest in bicycle hybrids does not disappear after purchasing a starter kit with a 250-watt motor, we can assume that you will soon have a more solid and heavier two-wheeled friend.

In general, as many people there are as many bicycles. Some people prioritize cost, others prioritize reliability, and others are interested in weight or external data. Today, ready-made solutions can satisfy the bulk of requests - among the variety of models offered, you can choose exactly the one that will fully meet your requirements. published

Currently, the bicycle is one of the most popular and popular modes of transportation. By cycling, you can get to your destination practically for free, while at the same time training a specific muscle group, thereby keeping your body in excellent healthy condition. The main advantage of such a move is the lack of impact on environmental pollution.

Cycling long distances can be somewhat tiring for the cyclist. To facilitate its operation, a bicycle electric motor was invented. The first models of such equipment began to be produced in 1998.

The first testers of this product were residents of mountainous areas due to frequent heavy climbs, which completely discouraged them from using bicycles. The bicycle electric motor was also immediately appreciated by elderly people who were not in the best physical shape.

Using a bicycle with useful equipment installed on it allows the cyclist not to put any effort into the riding process. In some cases, this miracle device allows you to move the bicycle independently, absolutely without any external effort, by charging the batteries and the electric motor.

Bicycle electric motor and its design

Refinement of electric motor models to their perfect form took place over a long period of time by more than one specialist, who developed several types of them:

1. Outboard motor.
2. Integrated motor configuration:

• with direct drive;
• gearbox

Each of the described types of engines has its own technological features, advantages and disadvantages during their operation. Typically, their selection is made in accordance with the wishes of the bicycle owner, taking into account its design features.

Electric motor for bicycles: main types

There are several types of motors designed for installation on a bicycle:

1. Motor - wheel.

Belongs to the category of the most common. It is used when converting an ordinary road bicycle. The engine is mounted on the axle of the front or rear wheel, and in some cases on both wheels. The appearance of the converted bicycle remains virtually unchanged.

Wheel motors come in different capacities, mostly from 150 to 2000 W. They can be made in three versions, each of which requires its own battery:

After installing the motor-wheel system on a bicycle, it becomes capable of accelerating its speed to seventy kilometers per hour. At the same time, without charging the battery, it can travel fifty kilometers. When moving towards a hill, the indicators of these criteria decrease.

2. Outboard engine.

This type of engine can be installed on any type of bicycle.

The equipment is attached to the carriage or down tube of the bicycle, and becomes an independent unit. A special casing must be installed on the motor together with the chain drive. The engine is powered by a battery, which is attached to the supporting platform.

The power consumption and speed of the bicycle are regulated by an electronic controller, controlled by a handle located on the handlebar. After the installation process is completed, the weight of the bike increases significantly. Its speed can now reach one hundred and twenty kilometers per hour.

3. Friction gear engine.

This engine is based on a special friction-type mechanism, which operates on the principle of transmitting the torque of an electric motor to the tire of a bicycle wheel. The main advantage of installing such an engine is the ability to mount it without first disassembling the bicycle. The disadvantages are:

• reduced wheel life;
• low efficiency;
• the need to constantly monitor tire pressure;
• difficulties of use on wet roads.

How to make a bicycle motor from scrap materials

The popularity of using electric motors is growing every day. Currently, they can be purchased ready-made or in individual parts for the purpose of independently performing the assembly process.

In order to assemble an electric motor on your own, you need to prepare the component elements in advance:

• controller;
• batteries;
• battery charger;
• engine.

The function of a device with electronic functions is performed by a controller, with the help of which the electric motor is controlled. The controller is responsible for supplying current from the battery to the engine.

The improved engine has an indicator that performs the following functions:

• provides information about the battery charge level;
• notifies about the speed of the bicycle;
• informs about the level of force pressed on the vehicle pedal.

The controller element sends signals to the indicator in question.

The electric motor also has a convenient property related to the ability to charge the battery under the following conditions:

• in case of a complete stop of the bicycle;
• when moving at a constant speed;
• when performing smooth braking.

Various batteries are used for electric motors:

• nickel metal hydride;
• lithium-ion.

When making an electric motor yourself, the battery can be attached in several ways:

• in a specially designated container;
• directly on the frame;
• in the frame compartments.

Motorcycle kits and special engines

The purchased motorcycle kits already contain all the necessary fastenings, which are universal for most bicycle models.

Many well-known manufacturers began to produce bicycle motors with power up to four horsepower. Installing such equipment will allow you to operate a bicycle without the need to pedal, allowing you to ride only using the electric motor.

Friction transmission

The principle of friction transmission is the transmission of torque between two rotating round disks, one of which is driven, and the second is driven.

The movement is carried out due to the friction force on the working surface.

The disadvantage of such a device is the high probability of slipping due to insufficient friction between the connected elements.

Classic chain or belt drive

The meaning of a belt or chain drive is the ability to transmit motion between two shafts located at a sufficient distance from each other.

Pulleys are put on each of the shafts, onto which belts or chains are attached. Normal movement is ensured only when the pulley connection elements are tense.

The simplest solution is a wheel motor

The wheel-motor system can be made independently. Installation is carried out using a wheel with a diameter of twenty to twenty-eight inches.

The operating principle of this device is to create torque in the rotor element due to the formation of a rotating magnetic field on the stator, which is stationary and interacts with the rotor magnets.

Electric motor - reviews from cyclists

I installed a wheel motor on my road bike. The appearance of my war horse has remained virtually unchanged, and I now have enormous opportunities in terms of travel. Plus, the battery is charged during slight braking or when driving at a constant speed. Very satisfied. Great opportunities opened up for me.

Grade:

Kirilov Evgeniy, Perm city