Model Generator Test Rig. Experiments on Home Made Power.




Introduction: Model Generator Test Rig. Experiments on Home Made Power.

About: no longer active.....

Project: To build a simple model generator to help me get my head round the idea of electricity generation.


Not so much of a how to but more a demonstration of materials that may give others ideas for their own projects.

This little model is made from

Tesco's best plastic chopping boards, it is very easy to cut drill and you can use self tapping screws The plastic has good self lubricating properties and allows axles to run smoothly with out the need for lubrication or bearings.  Its one downside is that it has to be screwed together as noting seams to stick this stuff.

6mm and 8mm Aluminum rod from B&Q about £4 a per 1mtr length

coils from scavenged microwave oven fans. These where used because I happened to have them at the time and this saved me from winding my own coils.

Tools used

Table saw

Pillar drill

Hole saws

self tapping screw nuts bolts etc.

Fun little project that is simple enough to build the plastic is easy to work and allows this to progress rapidly.

Note. the plastic shavings get everywhere so be warned best to hover up as you go along.

Thanks for looking.

Step 1: Its Like Building Your Own Lego Set

My idea was to make a set of parts that could be easily changed around into various different configurations.

I stated out by sawing 1 chopping board into strips on the table saw

1 piece 100mm wide form the base

the rest I cut into 50mm and 40mm strips these would be used for uprights etc.

The base was marked out and drilled with a uniform series of holes that would allow this little rig to easily to be altered at any time.

I used the hole saws in the pillar drill to make any of the circular parts.

I glue a paper template to the chopping board with spray mount. This had all the holes marked on and as long as i had the center drill of the hole saw on the right mark all the other holes would be spot on.

the center drill of the hole saw was something like 5mm so allowed me to drill the holes out to be either a sliding fit drilled 8.5mm or a tight push fit of 7.5mm for attaching to the axles.

A friend described this process as reminding him of playing with sickle bricks as it was is so easy to chop and change things as you tinker you invention to life.

Step 2: The Rotor and Magnets

 I had bought 36 10mm x 10mm round bar magnets for experimentation purposes.

I planed to use 12 groups of 3 in the rotor.

I had to laminate 3 disks together to be able to take a group of 3 magnets and seeing how this stuff don't stick I used 6mm alu bar as dowels to hold the disks together.

The center hole was drilled out to 7.5mm and was i nice tight fit, it started slipping a bit due to the pull of the magnets but this was easy to solve by using a pair of pliers  to make key the end of the alu bar which helps grip it tight.

The holes for the magnets are made to be a tight push fit. they are mounted so that they are alternately N S N S

Step 3: The Coils.

I scavenged the magnetron from a few broken microwaves at my local recycling depot. i pulled the fans out of them too as they looked like they had some fun potential.

I found 3 matching coils in the fan motors but one turned out to have a short in it

It attach them i drilled a 2.5mm hole through the laminated core and used the stems of pop rivets to nail them then to the plastic disk and the nails when ten clinched over, crude but effective.

By shear luck the coils are actually in phase with each other by default

I do plan to wind some proper coils to suit this little rig to see what it really can do. this will be a job for the winter months when I'm stuck indoors.  I will eventually do this and will post any details of the outcome.

Step 4: Bridge Rectifier, Simpler Than It Sounds.

This is the main reason why i built this test rig was to get my head round the bridge rectifier.

I dropped physics at high school in flavor of art. so my knowledge of electronics is a bit basic.

A friend gave me the diodes need to make this one, I first drilled the 4 holes in the plastic and bent the legs of the resister so the fitted in the formation and the leg where soldered together to form the contact for the wires.

Step 5: Bridge Retifier

This pic shows the back of the bridge rectifier and how the legs of the diodes where soldered together.

Step 6: Wireing

I scavenged the wire from an old computer power supply unit.

i wrapped the wire round the blade of a screw driver to give it the coiled look, this helps keep the wires tidy and gives a more pleasing finish

I used dog clips on the wire coming out of the bridge rectifier colour coded to positive and negative.

Step 7: The Crank Handle, Keeping It Simple.

A 4mm bolt and a the barrel of a cheap biro. The biro is wrapped in a small piece of vinal tape as they tend to crack if you even look at them crooked.

About as simple as it gets.

Step 8: The Outcome - Pure Raw Power, Well Maybe.

1.21giga watts!.....  well not quite. poor Marty must remain stuck in 1955 (forever avoiding his own mother... ahem)

The little rig produces up to about 20 volts if you crank it like mad.

Unfortunately its at micro amp level, just enough to light a led bulb.

Lets put it this way it works, and can help me demonstrate the production of electricity to those who make the mistake of asking me ;-)

Some day I will wind some small test coils that would suit this rig and see what it is truly capable of.

Well I hope you like my little show and tell, I hope that it gives some of you diy builders ideas for you own mini generators.

Thanks for looking.



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    18 Discussions

    i was just kicking it around in my head. and it dawned on me that this system built in the hubs of say a car. would be a nice way to charge a elecrtic car or bike.

    1 reply

    Are you certain that you didn't receive a kick to the head? ;)

    This was just and experiment, I learned a bit, not much but enough, i would almost need a refresher course.

    You are thinking of regenerative braking, where an extremely well designed and engineered motor can recapture a small percentage of the energy already used to power the vehicle up to speed but only in the few occasion where you have you brakes applied.

    For it to be practical you would need road with a steep enough gradient and several miles long that you vehicle would have enough momentum to keep it coasting while to keep the brake applied,  when you would reach the bottom of the hill the energy you gathered even if it was enough to fill the batteries to their max capacity those complicated laws of physics are most likely gonna work out that your vehicle will not have the energy to re climb the hill under its own power without the aid of additional energy input.

    Complicated aint it.

    Great start.
    Maybe this will be of help to you, a little project I made some time ago.

    1 reply

    I found your page back when I did this project. I would have used some of your stuff as the basis for what I did. I did try winding my own coils but they did not prove useful with the magnets I had at the time. the mini generator actually started out as a solenoid engine, it worked but just barely and it evolved into what I eventually posted.

    I doubt that I will build an alternator now direct drive motors are available, the LG direct drive motors are starting to show up in recycling plants now and they are ready to go. I had one only the guy I got it from took it back and destroyed it

    My VAWT did not stand up to extreme winter weather conditions and will need to be rebuilt. I'm not rushing things as my health is not the best at the moment and is keeping me from working at the larger projects.

    i was thinking of trying a Mini Lenz turbine (Well smaller than last time and built to a better standard) as a summer project I want to get to grips with the power making and storage side of things and would like to have a fully charged battery by the end of the season. I got the tools and materials, I just need the good weather to kick in and allow me to get things of the ground.

    Those magnets need to be real close to the ends of the coils.

    I take it you didn't pay any attention to what I wrote in step 1, this is model a mere toy and was built out of what I had at hand to test out a new pillar drill and band saw.

    You have simply wasted your time telling me stuff that I already know.

    Why would build my own stator etc when LG direct drive washing machine motors are starting to appear in recycling centers, I hand cranked one to just over 96 volts unloaded and under load was powerful enough to blow a 20W 12v bulb in seconds.

    Good evening everyone, this is an excellent instructable, despite being made out of cost effective materials and recycled parts this has a very professional look to it, I would imagine the main cost was the magnets, have you thought of using the coils from the wall socket chargers, this will give you the choice of fine and heavier windings to give you different voltages potentials on your generator rig, old dyson or any vacuum cleaner motor will have a good set of bearings and a steel shaft, all you have to do is remove the commutator windings , the outer motor windings will give you decent lengths of copper wire and the brushes can come in very handy for other projects, flat acrylic sheet can be found in scrapped flat screen computer monitors and smaller flat screen televisions and can be glued tapped or drilled, keep up the good work , hope these tips help, regards Doc Cox

    Hey all, Thanks for all the comments, the rig was never meant to be a power producer but a learning tool it was built just to work not be functional.

    This is an old project i have not continued work on as it has served its purpose as a learning tool.

    This little rig was built for a following reasons.
    1 to get an engineers eye view of electrical generation.
    2. to relearn old engineering skills that I had lost over the 20 years since i worked as one.
    3. to learn to work with new materials as my engineering life was 100% steel work.
    4. to learn new electronics knowledge and  skills.

    I do know it has potential to be a nice micro generator if I make a custom coils for it. I will come back to when the summer projects get put away.

    Lets just say that the interest from this post has put it back into the running for a this winters project.

    All the best,


    Looking at the pictures for this I couldn't shake the feeling something wasn't quite right... I think the coils are meant to be arranged "axially" to the magnets (ie. so the hole in the middle of the coil points at the magnet, rather than parallel to the rotor). Check out step 2 of this Instructable for an example of a wind turbine generator built that way.

    That could be why your gen isn't performing!  Other than that, I think generators with high numbers of turns producing high voltages at low current tend to need faster movement, so large diameter or very high RPM. If I remember correctly low-RPM generators tend to have low numbers of turns and put out high current at lower voltages, but also tend to have very tight spacing between the magnets and the coils.  For an experimental design like this you might be better off with some sort of simple gearing to increase the speed, especially if you are cranking it by hand so can't go much above 100RPM.

    On an unrelated note, I notice you appear to be in the UK (pounds and Tesco give it away) and building VAWTs.  Are you connected with renewable energy in any capacity, or is it just a hobby?

    1 reply

    Hey there, I'm from Northern Ireland. I'm working on this stuff just to keep myself sane, I suffer from Fibromyalgia and had to eventually give up full time work, this keeps me active on the good days, the brain is still active even if the body is slowing down. This was never designed to produce power, was throw together as a project to break in the pillar drill I had just bought. I know the coils are completely wrong, I may come back to it later in the year when I'm not as active outside. I posted it so it may inspire others to mess around with the idea of micro generators. Andy.

    Thats is really nice, the one I use looks nothing like that. Next step would be free energy but when you work with the materials for real, it looks like a idea that is far, far, far away... -thicker coils produce more amps but low volts, thinner coils produce more volts but less amps... (its not fair isnt it???)

    1 reply

    It looks a bit like a motorbike system (a bit), - how much power have you got our of it?


    1 reply

    about 20-24vlts if you you bust you self cranking it. I have a video if i can find somewhere to post it to. The coils are of 240v 50herts monopole motors the wire is fine as silk, way to many turn and very fine wire so gives respectable volts but just no poke at all in the amps department. As the late great Fred Dibnah used it say its just for de-monster-ation purposes, I have 6 3/4" by 3/82 rounds that I tried, the rotor was a fail as the wholes where to loose and nothing sticks to it even tech7 failed to make it more a loose push fit. I tried the 6 large magnets and the voltage went down to about 2 volts and failed to light the led. I know that a set of matching coils would do the trick and should produce a neat little micro generator as that plastic is totally weatherproof. I had looked into getting offcuts of a thicker cutting board 3/4" from a manufacturer but the guy i needed to see was on holidays. Must look into that again . Andy

    Hey, so what if you don't get a full T-watt out of this little thing. It was nicely executed and it can be the base for several devices if you choose to keep fooling with it. Btw, I thought that bridge rectifiers were made using diodes, not resistors. There's also another 'ible about making a generator that shows some good information about winding your own coils and fixing them to a plate. I think your cutting board idea would be perfect for that. It would be an excellent excuse to buy a small plunge router... Keep writing.

    1 reply

    Cheers, Thanks for the correction. Shows how little I know about electronics :-). genuinely great full for the correction. This rig started out as a jig for winding and testing coils, and I have an attachment that turns it into a solenoid motor but that just ate battery power and I never figured the timing out. Ill maybe go back to that idea some day to try and improve it as it was a fun little thing. I'm in the process of pimping up a lot of my power tools mainly wood lathe addons but one is for a Rota zip mod to be use with a 2 axis vice, I will be sure to post these as they happen.

    Very good idea. One makes a device and tries it, but almost always hasn't idea of its real performance...

    1 reply

    Thanks, Indeed, its very easy to do the maths and end up with what on paper looks like the savior of the modern world but when you build it in the real world it does not perform so good. I rather glad that I don't know the maths or never read the science books to start with so I'm not bound by what some educated people believe to be the limits of materials or ideas. This was just a fun project to educate myself and I hope it shows others how easy it is to build something small.