Building an Electric Scooter

Unfortunately, there aren't as many pictures of this project as there are for other projects - Fortunately, it's an easy project.

This is an electric scooter made from a kids push scooter, two batteries, and a fan motor from a Ford Taurus.

Here is the motor getting a flat spot machined in the shaft:

















The next item to accomplish is a way to control the motor - Preferably from the handle bar controls - What I did was modify a brake handle to accept a Normally Open push button switch. I epoxied the switch in the brake handle bar grip so that when the handle was gripped, the switch would turn on. That way if there was a fall it acted like a dead-man switch and turned off when released


You can see the wire from the end of the push button switch has been insulated by shrink insulation.

This approach works well other than the return spring is a little weak.


Now on to the motor controls - I decided to use an IRF1010N FET. These babies can handle 85 watts of power. Not too shabby. I mounted the FET on the back of a PC power supply heat sink along with a Schottky diode to prevent problems if reverse wiring happened.

The diode package contains two diodes back-to-back and was wired so use both in parallel thereby doubling the reverse current protection (PIV) - Now, I didn't actually try the theory and I don't have a lot of experence with shottky diods and don't actually know if my theroy is correct, but I put one on anyway - Maybe some day I will see if it actually works ;-)

Here is a picture of the FET and schottky diode mounted on the heat sink.

This assembly was mounted to the back of a plastic project box in which a cut-out was made for the components so they were inside the box.

Here is a picture of the box mounted in front of the rear wheel. - The foot board had a kick panel on the back which was drilled for wire ties which went around the box and through the heat sink to hold the box to the back of the foot board.



Here is the complete schematic. Rather than 1 big battery, I used two six volt batteries - It makes it easier to arrange the batteries for mounting.

Also, the switch is only a single pole - The schematic package I have doesn't have a single pole part and I'm too lazy to build one ;-)







The next thing to be built was a way to hold the batteries out of the way and securly on the frame of the scooter. I really wanted to put them on the bottom of the frame but was afraid of damage so I put them on the top of the frame and put the foot board on top of them.

This was helpful for my son who was a little shorter at the time.

Here is a picture of the battery box which was made from 1/4 inch angle iron and welded in a shape that fit the batteries. These could be then bolted to the frame of the scooter.


You can see the battery pack on top of the battery charger. To the right is the motor and just below the motor is the semi-curved mounting plate that was welded to the kick-stand that was inverted and bolted back to the frame.

With an additional spring so that a roller could be attached to the motor for correct gearing.

Below is a picture of the roller that was made by Formaster Tools in the Weber Industrial park in Ogden, Utah.




Notice the knurling done to provide additional grip on the tire.

This roller worked great - One unexpected phenomenon was that the roller got pretty hot when it was in action.

Here is another picture of the motor mounted to the kick stand and mounted to the frame.




Notice the screw holes with the lock screws for locking to the shaft






Here is a shot of the motor and holder welded to the kick stand.






You can see the opposite side of the kick stand also has the mounting plate for the motor - In case one wants to ride the thing backwards. -

Actually this setup was for two motors that would be on either side of the roller but proved unnecessary.

Also notice the hose clamp holding the motor to the mounting plate.


Top view of the motor and the drive roller.






















Wide shot of the completed scooter

This is what the scooter looks like in action


Pretty cool kids toy however; I didn't like the height of the battery pack, yes it was convenient but...


So, I built a holder out of cordura(r) fabric and moved the batteries between the structural piece of the frame and the down-tube.

It puts the foot board at the correct height and makes riding easier.











Here are some of the scooters that my friend has built - Similar in design. Notice the red one we call "the red Limo" has a counter shaft gear reduction system. It uses a motor from an electric lawn mower.









And one more...