Do-it-yourself electric scooter: photo of step-by-step assembly. How to make an electric scooter with your own hands tools and step-by-step instructions How to make an electric scooter yourself

By swapping out my car for a homemade electric scooter for trips to the store, I not only save money, but I also get a lot of pleasure from such “journeys”.

Right size

He planned to assemble a small scooter so that they would be allowed to pass on the subway and on the train: the frame was made in the form of an arc, as close as possible to the front wheel and enveloping it. The leg support was placed on the axle of the rear wheel, which further reduced the dimensions of the structure. I picked up the front wheel of a larger diameter - for driving over bumps and pits, and brought the smaller rear wheel as close as possible to the front one so that the scooter takes up little space in public transport.

Convenient frame

As a frame, I used a fragment of the rim of a metal barrel for 200 liters. (see photo, p. 1). using electric welding, I fixed it with one end to the bushing of the bicycle frame, which includes the fork, and attached a platform for the feet (2) and brackets for attaching the rear wheel (3) to the lower part of the rim strengthening the structure (4)

electric motor

I purchased a wheel motor (5) with a power of 350 W and a voltage of 36 V of a suitable size. I installed it on the fork at the attachment point with the help of lock washers (6). I welded a platform (7) to the fork, on which I installed a box (8) for the batteries and the wheel control unit. To set the scooter in motion, it took three 12 V and 7 A batteries connected in series. The charge of such batteries is enough for 15 km. over rough terrain, and on a flat road - a little more.

I charge the batteries with a car charger. The power switch is located on the steering wheel.

Important!
When mounting the motor-wheel in the place of its attachment to the fork, additional holes should be drilled for fixing washers. This will prevent the wheel from spinning.

A powerful battery... And an impressive cost. Yes, there are economy options, but is it possible to spend even less? And if so, how to make an electric scooter with your own hands?

Where to begin?

Decide on the basis on which you will make your iron horse. There are three good, tried and tested options:

• From a screwdriver. Drills and screwdrivers are convenient in that the battery is very easily pulled out of them for recharging. In addition, most models have several speeds, which is also quite a lot;
• From hoverboard. Very good in terms of battery connection and control, but quite expensive;
• Out of the engine cooling radiator. Perhaps the most difficult option from the point of view of implementation, but the motor is quite powerful and almost free (you can find a suitable engine at any auto parsing).

If you do not have much experience with such tasks, we recommend making an electric scooter with your own hands from a screwdriver.

Broadcast

Have you chosen an engine? Now it is important to decide how you will transfer torque from it to the wheels. The following transfer options are available:

• Chain;
• Friction nozzle;
• two gears;
• Hard transmission.

Again: if there is not much experience, put the chain. The option is controversial, because the chain can fly off and, but in implementation it will be the easiest way.

wheels

Which wheel will drive: rear or front? If you choose the rear, it will be easier with the installation, if the front, the scooter will be better controlled. We advise you to still get confused with connecting the front wheel, it's worth it. The wheels themselves can be taken the most ordinary, with plastic discs. Garden cart wheels work well.

Frame

The frame is made from ordinary steel pipes. Profiled steel with a thickness of 2.5 millimeters will be quite enough for a do-it-yourself electric scooter to withstand a load of up to 100 kilograms.

IMPORTANT: If you are making an electric scooter not completely from scratch, but on the basis of a conventional - not motorized - scooter, you will not have any issues with the frame and wheels. Just choose from durable and stable models: very elegant ones may not be ready for serious loads.

Battery

Do not take heavy lead batteries! You most likely won't be able to tuck them neatly under the deck and the battery will just break the whole balance of your scooter. If you do it on the basis of a screwdriver, there are no questions - use your own battery - if not, look at for electric helicopters, the same drills and similar equipment.

Also you will need

• wires;
• Button or toggle switch;
• Plastic box for battery;
• Fasteners (as a rule, these are bolts and nuts).

It is not necessary to use welding or similar technically complex fastening methods.

How to make an electric scooter with your own hands?

The best choice would be to watch a video on YouTube before starting work. Look specifically for the assembly of the scooter based on the engine you have chosen and with the gear you have chosen - there are videos for almost all existing options.

And, in any case, you will need some experience in working with your hands. Ideal if you have already worked with electrics and metal. If there is no experience, we strongly recommend finding an assembly partner or at least a consultant - a person who can look at your idea and project, give their comments on it.

If you do everything carefully, a do-it-yourself electric scooter will cost only 5-7 thousand rubles, which means you can save a lot. Good luck with the build!

In this article I will tell you how to make a powerful engine for a scooter or a children's electric car with high efficiency and a simple controller for it at home.

The first thing that will shock you is that there will be no iron in this engine. No need to cut the stator or rotor plates on laser equipment, assemble into packages and adjust the entire structure to micron accuracy. This usually prevents ordinary people from building engines themselves. You will be surprised how simple the design is and you will not believe the characteristics obtained from it.

Usually, when you search on YouTube, for example, “do-it-yourself electric motor”, you see a coil and a magnet and it rotates and everyone knows that yes it works, but the efficiency there is negligible and cannot create normal traction. But, everyone is mistaken, in fact, using the right coil and magnet, you can make a powerful engine with high efficiency.

How it all started. Once, while looking through patents for engines, I noticed an engine made of a coil inside which a long magnetic rod mounted on a shaft rotated, this design did not become widespread due to low efficiency due to weak magnets that were at that time and a little wrong design. Looking ahead, I’ll tell you what the ideal design of the engine should be - a spherical magnet fixed on the axis with poles perpendicular to the axis around it is a round coil of square section (the axis passes through it, so it can be divided into 2 parts and placed closer to the axis) - that’s all - the design is ready, it remains to fix everything in the case and you get a two-stroke engine. True, I have not yet been able to find such a magnet for sale, but if everyone starts making such engines, they will soon appear.

Now on sale there are magnets - cylinders diametrically magnetized with a hole along the axis, they are almost perfect (there is no better for now), they are generally not cheap, but still cheaper than finished engines by 2-5 times, the largest inside the coil with current (15A 100-200 turns) cannot be turned by hand already (for the magnet, not for the axis, but for the axis and with pliers, do not turn). My first fear was when I started such an engine on a scooter - it was whether it would accidentally break the toothed belt at the start. That is, you understand that these are no longer those toy engines with a coil and a magnet that you see on YouTube.

Now about the efficiency, everything turned out to be very simple and predictable, when the cylinder (sphere) magnet is turned with its poles to the turns of the coil, then the force of the magnetic field acts on the magnet tangentially, that is, perpendicular to the radius, creating the maximum torque, and when it is turned by the poles along the axis of the coil, then the torque is zero, which means that in this position, if a current is applied to the coil, it will go into heating all 100% and the rotation efficiency = 0%, and when it is turned by the poles to the coil, then the efficiency is maximum and depends on the steady current at a certain load. For example, if at this point, with a supply voltage of 10V, a current of 1A is established, then the total resistance (active + reactive) = 10 Ohm, and if the resistance of the winding itself is 1 Ohm, then the efficiency at that point is 90% (and, accordingly, if the winding resistance is 0.1 Ohm then the efficiency is 99%. Conclusion - the winding should be with as little resistance as possible and it must be powered at those points where the efficiency is maximum; they definitely cannot be powered when the magnet is rotated along the axis or almost along the axis, since this is 90-100% loss (heating). And you can make sure of this if you assemble a simple driver on 2 keys (diagram at the end of the article) and apply control from a microcircuit from almost any cooler with 4 outputs (a cooler control controller with a built-in hall sensor and 2 outputs that are usually connected directly to the windings). Efficiency will be at the level of 55% (maximum 72.2% minus resistance losses depends on the load on the motor). You probably already understood how to increase the efficiency, reduce the feeding angle from 180 degrees to 90 - 45 - 30 - 15, the less the efficiency is closer to 100%, but the thrust decreases. Where is a reasonable limit, it turns out at 180 angle we consume 100 watts, we give 50-70 watts to the load, if we reduce the angle to 90, then we consume 50 watts and we give it to the load 37 - 44 - (maximum 89.97% - losses) efficiency is higher but the output power lower at the same supply voltage, 120 degrees (it will be similar to a 3-phase theoretical maximum of 86% - resistance losses). Need an engine with high uniform thrust and 95% efficiency? It's easy - take 6 magnets on one axis with a coil or magnet angle offset of 30 degrees, we get a 6-phase 12-stroke engine (similar to a 12-cylinder internal combustion engine) with an efficiency of up to 97.2% which can also be reprogrammed to any other phase angle and sacrificing efficiency to increase thrust by another 2 -3 times if needed.

The sketch below shows the design of the motor and the placement of the hall sensors (in the example, the hall sensors are separated from the middle of the coil at an angle of 45 degrees, which gives a 90 degree winding feeding angle when the magnet poles are as close as possible to the coil turns)

My single-phase two-stroke engine with a feed angle of 110 degrees gave an efficiency of 87% at a speed of 13 km / h with a load of 92 kg on a flat road, while the windings sealed in a closed wooden case heated up to 41 degrees for an hour of continuous driving with an average engine consumption of 88 watts. Two windings of 125 turns in parallel with wire 0.83 mm in diameter, magnet 65 in diameter, 30 height, internal 18 mm link. In the amount of copper 260 grams based on 260 watts. My weight is 85kg (8kg scooter with motor and battery, lighter only in carbon), food 10x Samsung INR18650-25R = 87Wh (42V maximum with center tap, 2.5Ah) I have enough full charge for ~ 15 km on a flat road.

Initially, 1 hall sensor was used (but I already knew that this was a big loss since I had made such engines before), so the engine at idle consumed 42 W (1 A for each half of the battery, total 2 * 21 or 1 * 42) and in 2 minutes it heated up to 50 degrees (this is without load), the installation of 2 hall sensors reduced the no-load current by 10 times! and it was 100 mA (4.2 W) and it stopped warming up. At the maximum load (driving uphill), the current reached 6 amperes (> 250 W) and the winding warmed up so that it was impossible to drive for more than a couple of minutes, and after installing 2 hall sensors and supplying power to the windings only at the right moments, according to the figure above, it completely solved the problem of overheating (significantly increased efficiency) and the current when driving on the same hill fell by 2 times (130 W)

And so the magnets with the coils are packed in the case, the shaft (the M6 ​​100mm bolt on which the magnet is fixed with nuts with a side, clamping for the wheels, through the washer and the rubber gasket) is fixed in non-magnetic steel bearings (this is ideal, but I used ordinary cheap steel but force the magnetic field is such that they spin with difficulty, so it’s better to put a stainless steel right away) and most importantly, how to start it now. I used the simplest option - one coil and one magnet - the cheapest option and it fits perfectly for a scooter, of course, since we only power a 90 - 120 degree sector per cycle, the sectors remain unfilled with thrust and such an engine will start with a push, but this is not a fan and the engine for the scooter, pushed off, turned on the engine and drove off, everything is simple. If you need an autostart, then at least you need to do a 2-phase 4-stroke, I put this one in a children's car.

Controller

I associate the phrase "pwm regulation" with losses, you need to power it with direct current to avoid switching losses on the keys and not to heat the diodes in the keys, in general, the controller can operate with an efficiency of 97% or more if you forget about PWM, and it is better to regulate the speed with the supply voltage (for example, in my scooter it is fixed at 13 - 18 km / h, depending on the weight of the rider). Powering the winding with two cycles is possible either with a bridge, but then the losses are always on 2 keys or a half-bridge powered with a tap from the midpoint, this option is chosen because it reduces the losses on the keys by 2 times (the coil is always turned on only through 1 key). Another advantage of such a half-bridge is that when the coil is turned off, the back emf merges through 1 diode into the opposite arm and the losses on the diodes are also 2 times less, that is, more energy will return to the capacitor / battery as well from the recovery from rolling down the hill. As a result, we get a half-bridge + half-bridge driver + control circuit.

Control scheme

The use of one hall sensor does not make it possible to control the angle at which the winding is powered, therefore, you need at least 2 sensors located in such a way as to get the windings turned on in the desired range, the easiest way is to make an angle of 90 degrees (for this you need to space the sensors 45 degrees from the turns of the coil in both side) then a pair of sensors is enough for 4 cycles (we use only 2 of them for single-phase). Each sensor returns 2 positions that mean whether it sees the north or south pole, so when both see the north one, turn on one key, when both see the south second, when using microcircuits from the cooler, it is implemented by logic 2or-not, power is supplied to the inputs of two logic elements through the resistances at the outputs at the same time 0, the cooler microcircuits switch the inputs of the logic elements to zero, when both inputs are at zero at output 1, 1 key is turned on, and also when both inputs are at zero on the second logic element, another key is turned on. Everything is simple. Keep in mind when choosing a cooler driver chip (hall sensor) that they are available with and without stop protection, for a support engine like mine on a scooter it is better to use it with protection, it will only start at the start of the ride, but for an engine that should start itself, you need to choose without protection and do it if necessary in another way (overcurrent protection for example).

I didn’t have logic chips, so I replaced them with transistors. Mosfet driver connection diagram according to the datasheet.

Engine Debugging

I want to note important points that will save the controller details from accidental burning. The fact is that the back emf from the coil is a very insidious thing, it can burn all the electronics and the driver and microcircuits with the hall sensor. To prevent such situations, it is imperative to have capacitors at the power input into which the back emf from the coil merges (through protective diodes in mosfets) in case of accidental disconnection of the battery, at least 1000 uF 50V with low esr. Also, to prevent high voltage surges from entering the driver output through the reverse capacitance of the mosfet, a 13-15V zener diode must be in the gate-source circuit (which is lower than the allowable gate voltage of 20V but higher than the control voltage from the 12V driver).

When you first turn on the winding, it is better to connect it through a resistance that limits the maximum current (10-50 Ohms), by turning the hall sensors we achieve rotation in the right direction. Also by moving the sensors, you can find positions where idle consumption will be minimal and engine operation is quiet. It is not necessary to greatly reduce the feeding angle (< 90 град) для двухтактного двигателя, хоть потребление будет и ниже на холостом но создать достаточную тягу будет сложнее так как в меньшие промежутки времени придется вложить больше мощности а это дополнительные потери на контролере и батарее.

Price

• bolt (shaft), nuts and washers (fixing the magnet and bearings), non-magnetic screws (stainless steel, for twisting the housing)< 2$
• body (beam 1.5m x 80 x 20) = $ 1.3
• gears and belt = $8
• magnet = 50$
• boards and all details< 10$
• 10x Samsung INR18650-25R = 38$

In total, the electrification of the scooter cost ~ $ 110

Advantages and disadvantages

Pros:

• the engine rotates without any resistance, which does not interfere with the ride on the scooter as usual when the power is off
• light weight
• high efficiency

Minuses:

• you can not install such an engine near magnetic materials (it will lead to sticking of the rotor, the use of iron bolts in the body is also unacceptable, only stainless steel or glue)
• cannot be installed very close to massive conductive materials (eddy current braking, it is ideal to use a frame made of plastic, wood, carbon then you can put it anywhere)
• come up with and write in the comments (low speed does not roll, you can increase the voltage, I am satisfied with the speed for driving on footpaths)

Big photo

Pressing the belt for more grip on the cogwheel

First switching on (with 1 more hall sensor and reduced supply voltage 2x8V) maximum speed 3-5 km/h

Adjusting the position of the sensors (we ride, measure consumption, re-glue the hall sensor, look for the best option) in the photo is the best

The front part is made of mountain, a hand brake is also installed here. As for the rear, it uses a smaller diameter wheel from a children's bike. The author got the bikes almost for free. To create a powerful frame that will not sag under the weight of a person, a thick-walled metal pipe is used. The scooter is assembled quite quickly and simply. It is enough to have some initial skills in working with the tool.


Materials and tools for the manufacture of a scooter:
- the front of a mountain adult bike;
- rear fork with a wheel from a children's bike;
- steel plates;
- screws;
- a piece of strong metal pipe to create a frame;
- spanners;
- welding machine;
- Bulgarian;
- drill;
- dye.

Scooter manufacturing process:

Step one. We disassemble bicycles
First you need to get the necessary elements to create a scooter. From a mountain bike you will need a front fork with a wheel, you also need to leave a handbrake. You need to take a grinder and cut off the frame from the front fork, as you can see in the photo. In addition, there is also another option, you can not cut off the lower part of the frame, but simply extend it with a piece of pipe if it is stiff enough to create a scooter.

As for the rear fork from a children's bike, it all depends on the design. If this is also a mountain bike, then the plug can simply be unscrewed. If ordinary, you will also have to work as a grinder.

Step two. We create a frame and weld the structure
To create a frame, you need to take a metal pipe and bend it so that it is approximately the same shape as in the photo. The pipe must be strong so that it does not bend under the weight of a person. One end of the pipe is welded to the front fork, and the author welds a metal plate to the other end. Further, the rear fork is already welded to this plate, so the design is more reliable, since the rear wheel has the greatest load.

Step three. We attach a board
To make it comfortable to stand on the scooter while riding, you need to fasten the board to its frame. For these purposes, first you need to weld 2-3 metal plates to the frame and drill holes in them. Well, then the board is simply screwed to the plates using screws with nuts or self-tapping screws. In the board, you will need to make a cut, as in the photo, so that the frame enters it.

Step four. Scooter painting
You can paint the scooter to your taste. The author used matte black spray paint for the frame. As for the board and rear wheel, a bright pink fluorescent paint was used here. It was this color that most of all went to the liking of the author's daughter.

That's all, now the scooter is ready for testing.

27.09.2018

When choosing a personal electric vehicle, it is not necessary to limit yourself to typical factory models. You can assemble an electric scooter yourself, with your own hands, as much as possible corresponding to the existing requests and needs. To do this, you need a regular scooter (base), a motor-wheel, a battery and a controller. You will also need controls for the alteration - brake levers, a throttle lever and a power switch. Bases of scooters, depending on the diameter of the wheels, are divided into the following types:

1. micro - up to 8";
2. mini - 8-10";
3. midi - 12-16";
4. maxi – from 20”.

In addition to the diameter of the wheels, their width may also vary. Scooters, Evos and similar models are also considered scooters, but outwardly and in terms of motor power they are more like electric scooters. The type of base affects the driving characteristics of the electric scooter.

Decide on wheel size

Before you make an electric scooter yourself, you need to decide on the features of its design. Of great importance are the size and type of wheels (they can be cast or inflatable), the presence of suspension, the size of the dropouts for mounting the motor wheel and the location of the battery. The optimal wheel diameter depends on the quality of the roads you are going to drive on. The “micro” option is only suitable for rolling on tiles and good asphalt. "Mini" - allows you to overcome small obstacles on the way. "Midi" allows you to confidently ride at a speed of 40 km / h and above, without fear of small potholes. "Maxi" is great for those who like to drive on rough terrain and problematic roads. The suspension partly smooths out the bumps. But there is a rule - the wheel is able to overcome an obstacle that does not exceed 1/2 of its diameter.

Choosing a place to install the battery

Li-ion battery can be placed in various parts of the scooter:

There are many nuances in the question of how to make an electric scooter for adults with your own hands. So, the size of the motor-wheel is selected depending on the width of the dropouts. Particular attention should be paid to the choice of the battery, because the weight, ease of control and range of the electric scooter on a single charge depend on it. Modern electric scooters are equipped with lithium batteries - assemblies of lithium-ion cells, LiPo or LiFePO4 batteries. Batteries made from Li-ion cells are lighter and cheaper, while LiFePO4 batteries last longer and are not afraid of frost.