Dinabike

Electric Bike with energy generator.
This project was developed by students from 12^th of a vocational Course of Computer Maintenance at EPFelgueiras (Portugal), as part of PAP project under my orientation. The goal was to build an electric bike under European legal rools but with a good performance and autonomy that could be used daily in a frequent up and downhill area, not realy appellative for bikes uses. Half year after, dinabike as over 2600 Km (1600 Miles) with no problems at all, except for regular maintenance: brakes, tires and a few tunings.

Step 1 Stator Windings

After a logic option for a electric bike convertion kit with 250W brushless motor, rear gear and 36V 10Ah Ion-Lithium power, left to profit downhill to produce energy to improve the autonomy of the bike. After some wrong options and consequent changes we've come to this solution. We decided to Build a new axis for the front wheel, wich was able to support, inner rays, magnets and the stator. 
 We began by  the stator building a gadget to do the copper winding. 
 For a correct placement of the coils we designed and cut with a computerized milling cutter a polyester mold as shown in the picture.

Comments

[inblack]

Quais sao os custos de construção deste projecto?

The costs of the project?

[ElectroFrank]

When you say, "spheres", do you mean ball bearing races ?

[matiasbela]

Looks very nice and clean !

Is it abble to provide power to a brushless motor ? ( charging a battery ) and if so, do you know how much time is it needed to pedal ?

[ajtorres]

Para além de se tratar de um projecto PAP de 4 alunos de uma escola profissional, que sempre têm alguns Euros para estes projectos, Já devem ter reparado que foi colocada publicidade nas decorações da bike que também serviu para tapar os fios. Todos ajudaram e a obra fez-se. Sem ajudas seriam precisos 1000 Euros e muitos dias de trabalhos.
Agora em Inglês senão ainda somos castigados.

With none publicity and if it wasn't a School project, you will need about 1000 € and a lot of days of work.

[ajtorres]

No. I would like to have used bearing races, it would be much easy, but not. It's really, in each side, we have 2 pars of 9 steel spheres, that we put together, one by one.

[ajtorres]

As you may know in Europe we use the PAS system. That means you have to pedal for motor to work. If you stop pedal the motor stops too. It's much healthy I think. So, if we always have to pedal the goal was to extend the time (ou space) during which the motor can assist you.

[Corny76]

Aluminium is better in atmosphere conditions, it is rust resistant material.

[dsantacruz]

hi im colombian, i am interesting to build this great machine, i want to have more information about how to make the alternator and how put it in the well of the bike. could you write to my mail: [e-mail]
thanks!

[BrianHuntley]

So "loose bearings" as opposed to "cartridge bearings"?

[ilpug]

Very well done. 5 stars man.

[Mannyf]

Not to put a damper on your product, which I think is a great idea, but
I read in this morning Atlantic City Press, That some Towns within the State of N J, consider Electric Bikes a Motor Vehicle. And as such must be register, Insured and be operate by a Licsensed Driver.

The city is Ocean City N J.

[gotwind]

Did I read that you are using alluminium for the rotor discs?
You would get considerably better performance using mild steel to focus the magnetic flux path. Nice idea though, well done.

[blipvert]

Yes! Steel has 100X the magnetic permeability of aluminum. Think about the magnetic circuit, how the field lines pass from the magnet through the coils and back to the magnet. Use steel to follows these field lines wherever possible, every little bit of magnetic field passing through steel instead of air or aluminum boosts your efficiency dramatically.

[ajtorres]

That's it. You are right. But if we used steel provably the bike not even moves. The idea was to reduce the tork even we use strong magnets.
Better idea would be to have 2 or 3 combinations of windings that could be used automatically in a progressive way, giving more magnetic force in a more speed conditions. At the beginning we have thought on that but in just a school year we have no time for more. They have not only the technical disciplines, but also the Math, Portuguese, English, and so on.

[Zaen]

I notice that you didn't use steel core windings, or steel backed plates to increase flux density between the rotor and stator. is there any particular reason that you did it this way?

Also, I was wondering if you did any analysis prior to building it? or was this more of a build and test approach?

In any case, excellent writeup and a very cool build!

[ajtorres]

The plates are originaly not in steel, by option. For all we knew from wind generators, if we used steel, we will have a great force to move de plates, knowing, that we'l have between 100 and 300 rpm. The option was too use stonger magnets instead of steel plates. In project we have thought on put steel plates, from old transformers in the middle of each coil but the space was very reduced.

[RammingSpeed]

Great article. Could use a parts list and sources for things like the batteries

[Ravundra Pardeshi]

Congratulations for a good instructable. Some how I missed following details if I want to replicate the generator.
1. Diameter of coil disc.
2. Dimensions of windings.
3. Number of turns and wire thickness.
I shall be very happy if you can give this info as well any other details required.

[ajtorres]

sorry but I left some technical details just to the interested ones.

1 - Diameter of coil disc is 18 cm
2 - Dimension of windings - The coils are rolled in 2 pars of screws. The closer par that stays nearest the center, 1,6 cm (red line in picture); The farthest par 3,2 cm (blue line). And in the axys between this 2 pars of screws we have 4 cm (Green line - I'll try to upload a image with this dimensions).
3 - Nr of turns an wire thickness - 80 turns of 0,5 mm glazed copper

[Ravundra Pardeshi]

Thanks for the quick reply.

[loki2012]

Nice instructable! Not sure about the mercury tilt switch, if I am identifying this part in the picture correctly. I like thayray's idea of a switch on the handlebars, perhaps squeeze a little to activate the generator, keep squeezing for the brakes ...

[siafulinux]

What a clever idea! Nice.

[yashiro]

I dont see how many turns per coil you have. Can you share that information with us?

[Flying_MashedPotatoes]

cool, a generator that generates "Dinabikes" style bikes :D

[thayray]

Seems like you could have rigged it so that the handle for the front brake serves as the on-switch and releasing it turns it off. That way you wouldn't lose your momentum unless you intend to slow down or stop.

[rhkramer]

Nice project, thanks!

To gotwind: Exactly how would you orient the magnets and the mild steel?

[Windy Miller]

Thank you for making this instructable so clear! I've been toying with this idea for some time and this just makes it all so easy. I cannot thank you enough and will hopefully post my success at a later date

Windy

[Mr. Rig It]

This is awesome!

[ARJOON]

how much power does generate at a speed of 20km/h

[ajtorres]

At 20 Km/h, it's about 160 rpm, and generates about 5 Watt power. But I always get more speed at downhill conditions, between 30 and 50 Km. Don't forget we have some loss of power on growing Voltage to 40 Volt.

[Wasagi]

Not only is your setup really good looking, it's genius!!!! Thank you!