The Wimshurst influence machine was a popular machine at the end of the 19th century to generate high voltages.
From it's development ~1883 it superseded other devices such as the "Holtz" and "Voss" machines. It was one of the first ways to generate high voltage to more or less conveniently take Röntgen pictures around the turn of the century. For example, this 1909 book on radiography: Radiography and the "X" rays in practice and theory with constructional and manipulatory details by S.R. Bottone has an interesting chapter on Wimshurst machines, how to hook them up to a Crookes tube and how to take X-ray pictures. My little Wimshurst machine should in theory be able to do the job, but it will take a very long time to get 10 good flashes. And the tiny crank is not ergonomic. And I don't have a Crookes tube.

The Wimshurst machine got superseded around 1924 by more practical generators like the Marx generator which is still used today in laser printers and CRT television (Although those are getting obsolete too).
And for extreme high voltages, it got replaced around 1929 by Van de Graaff generators which were used for example for the early particle accelerators


This instructable will show how I built a small Wimshurst influence machine with two CDs, pieces of scrap cardboard and some tin foil. These are instructions for materials and tools that I had lying around, just to provide ideas for other people. Of course it would be better not to use cardboard and to make the device much larger.

The instructable consists of the following steps:

Step 1) First, the workings of a Wimshurst machine will be explained.
Step 2) The materials and tools are shown.
Step 3) CDs are cleared.
Step 4) Metal strips will be made from aluminium foil AND aluminium tape and glued onto the CDs.
Step 5) Wheels are made and glued to the disks.
Step 6) The axles are mounted in a support structure.
Step 7) A socket is made that will hold the mechanism.
Step 8) A base is made on which the Leyden jars and the mechanism will be mounted.
Step 9) Two Leyden jars are made.
Step 10) The neutralizer rods are made.
Step 11) A crank is made.
Step 12) The sides of the socket are closed up.
Step 13) The base is adapted so that everything can be mounted without them shifting around.
Step 14) The electrodes are constructed from wire and aluminium foil.
Step 15) Debugging
Step 16)The results.

A very interesting website containing all sorts of builds of all sorts of electrostatic machines is the following:


If you have any interest in this subject, it is really worth checking out.

There is also an other instructable: http://www.instructables.com/id/Whimshurst-Generat...
The build process isn't really documented, but there is a list of materials. If you look at that, you can most likely find the equivalent in my machine with some documentation on its function and how it relates to other parts.

Step 1: How a Wimshurst influence machine works

As this is an electrostatic influence machine it evidently uses electrostatic influence or induction to generate static electricity.

This electrostatic induction is nothing more than the effect of a charge onto nearby objects without a physical contact. For example, a positive charge will attract a negative charge and repel a positive charge. Therefore, in a conductor, charges will be redistributed as to make the electrostatic potential constant throughout this conductor.
The classic example is an electroscope in the vicinity of (but not in contact with) a charged object.
This is a video of the youtuber RimstarOrg which gives a very good explanation on electroscopes. (he also made a CD wimshurst machine, but mine is esthetically a bit more elegant and requires far less tools)

Most electrostatic machines use inductance to produce a net charge in an object. The simplest version is an electrophorus.
If for example a positive charge is brought near a conductor, it can be seen that this conductor is polarized. (simply said, this positive charge moves all the (negative) electrons a bit towards it. And of course charge x vector is a dipole moment.)

Fig. 1 Conductor in vicinity of charge

One can now ground the end of this conductor which will remove the positive charge located there

Fig. 2 One end is grounded

If one then removes the connection to the ground and the inducing charge, one can see that there is a net negative charge left in the conductor.

Fig. 3 A net charge remains

This is a video of such an electrophorus in action. Check out the channel of this youtuber Thomas Kim. He has all sorts of interesting electrostatic machines made from PET bottles and CDs, he doesn't provide much information, they are probably intended as demonstrations. He also has a CD wimshurst machine. (but mine produces bigger sparks. I did get the Idea of using aluminium tape for the second pair of disks from him.)

A Wimshurst machine and all other electrostatic influence machines are nothing more than elegant, mechanized versions of a sort of double electrophorus.

A Wimshurst machine consists out of two parallel, counter rotating discs with metal strips. The strips pass under so called 'neutralizer' rod which do the separating out of the charges on the strips and the strips also pass under combs which harvest the accumulated charge on the strips.

An excellent explanation of the workings of a Wimshurst machine can be found here:


It is however French, if you know some French, it definitely is worth a read (as it also gives instructions on how to use a Wimshurst machine for electrostatic painting).

The machine I have built is the mirror image of the one explained in that link, so I will give a brief, parallel English explanation.
One can see in the main pictures of this step, that there are 6 different zones on the discs. (and since everything is symmetric, those same 6 zones appear on the other side of the discs)

zone 1
Even before the discs start spinning, there will be some static charge on the metal strips. Because just touching or handling the disks is enough to charge them a minuscule amount. This charge will amplify itself as the discs are spinning.
For example, the schematic starts in zone 1 with a net negative charge on the back disk strips. The field of this charge induces some polarization of the second disk. In much the same way as Fig. 2

zone 2
As a front metal strip passes under the front brush of a neutralizer rod, some negative charge gets repelled trough the rod to a strip on the opposite of the disk.
This is similar to Fig. 2 where the "ground" is replaced by an other piece of conductor.

zone 3
When the contact with the brush of the neutralizer rod is lost, a net positive charge remains on the strip. (If you subtract a negative charge, you're left with a positive charge) Similar to Fig. 3
So, the back disc still has the net negative charge and the (upper) front disk strips now have a positive charge.
Secondly, the front disk strips on the other (bottom) side now have a net negative charge.

zone 4
Remember that the back disk also turns, but in the opposite direction. In zone 4, the back disk gets in contact with the back neutralizer rod. And the negative charge on the back is produced in exactly the same way as in zone 2.
The positive charge repels the positive charge (or attracts negative charge since it's mainly negative charges that move) on the other side of the disk.

zone 5
Similarly, zone 5 is the opposite of zone 1 wherein the net positive charge on the front disk polarizes the back disk. As the back disc moves towards zone 4.

zone 6
Here, the strips of the back disc and the front disc with the same charge pass under a comb-like structure.
As both strips on both disks have the same charge, they repel each other. Secondly the comb acts like a Faraday cage so the charges on the strips desperately want to escape outwards toward the comb. And this is what happens.
The comb does not need a physical contact with the strips as it has conducting points and electric fields towards points are always very strong, so there the air will break down a bit and the resulting ions provide a path for the charge on the strips to escape towards the low potential of the combs. When running a Wimhurst machine, this is visible with a small purple line from one of the points to the disks.
The charge on the combs immediately gets diverted towards Leyden jars where the charge/voltage will build up till there is a spark. (preferrably in a spark gap, or across the strips of the disk) Or, if there are much sharp edges, it will go away in coronas or ionic winds.

Wikipedia has an interesting animated gif that shows everything said previously
in an animation, but it is a bit complicated to deduce how everything works from it and the compact explanation with it.

In theory, the metal strips are not really necessary and this should be possible with only some charge on the surfaces of the disk. A Wimshurst machine without metal strips on the disks is called a Bonetti Machine. But one needs a static electricity generator (for example an ordinary Wimshurst machine) just to start this generator.

<p>Greetings.</p><p>That's a great project idea and I chose this schematic because it is the most compact and well-thought frame for the discs I have found on the net. </p><p>However, I used 5mm PVC foam board instead of cardboard and it was definitely a decent material choice. I also changed the way combs are attached to the frame that makes them independent from layden jars and designed my own version of the combs themselves that proved to be very reliable and easy to make.</p><p>Pulleys are made of the same PVC discs attached to an electric drill and sanded to a desired shape.</p><p>I also made vector images for all the parts needed for this project so that I just printed them on A4 sheet, stuck them to PVC board with double-layered duct tape and used a jigsaw to cut them out. </p><p>In the attachment first 3 images is my result machine, 4th image is how I made the combs, 5th image is an easy way of making a sphere(ping-pong ball with sticky aluminum foil). </p><p>And finally the archive with all schematics I used:</p><p>https://dl.dropboxusercontent.com/u/25635148/Handmade/Wirmshurst/Schemes.zip</p>
<p>wow, this is such a great porject, I am in middle school and I wanted to make a wimshurst machine for my science project, then this came along! so Sparticles u da best, this is the only place that provides a simple, cheap, easy, and neat looking results for this kind of machine. I'm not the real science expert, at all, but I think I may know why having one large ball and one smaller one provides a larger spark. After researching, the ball shape prevents such a great electric field around the spark gap, and because the sizes are different, the electric field is distorted even more than if the balls were the same size. This allows the charge to build up more than it usually would before it sparks? Or, because the machine needs an imbalance to start charging up at first, the different sizes allow greater charge differences to exist? Im not entirely sure, but it almost makes sense to me. Thanks for reading this though.</p>
<p>Hello, good luck with your science project.<br><br>You're correct about the balls preventing a strong field. But the difference in size between the two terminal balls is because electric breakdown happens differently at the positive and negative terminal. The air breaks down easier at the negative terminal (because electrons are small and mobile) than the positive terminal (positive ions are big and slow compared to electrons).<br><br>So, to have bigger sparks, the negative terminall usually has a bigger ball.<br><br>The only thing a wimshurst machine does is amplify an initial imbalance. But that imbalance is random. (for example you are charged a bit and you induce a small imbalance yourself) So you don't know in advance which terminal will be positive and which will be negative. So I just placed the balls on the terminals randomly.<br><br><br>Now I think of it, you could totally choose which terminal will be negative! (or positive)<br>Before you start the Wimshurst machine, rub a balloon on something and let it touch the terminal you want to be negative. (this will set the initial imbalance that will be amplified)<br><br>Good luck, have fun!</p>
<p>Lol, I just realized that I spelt project wrong. Thank you so much for your involvement to my previous reply, it's really exciting to see that such a great instructor cares about what I have to say. Thank you because now I understand how the different size of balls can affect the spark size. Now I have even more research for my science project!</p>
<p>and also, I created a instructables account because I wanted to reply to this project. I named myself wizard of lightning because I like wizards (they are cool because they can use force of elements kind of) and lightning because I love static electricity. It's the coolest form of energy to me. Nothing more exiting than having the power to summon lightning on a bag of popcorn. *yummm*</p>
<p>Thanks for your great comments.<br>It looks great! <br>My cardboard version has broken down and I've made vector image template of most of the parts for a laser cutter. (although I'm planning on changing my design as I want my template to be independent of the thickness and more easy to assemble (preferably without glue))<br>Someone suggested making a kit version some comments down, although this project has been in limbo for a while. Your nice comment has resparked my interest in continuing with it. Thanks!</p><p>There is a fablab with a lasercutter in the neighbourhood, I'm planning on checking it out this week.<br></p>
<p>A few more things I've forgotten to mention that may help someone:</p><p>- I tried erasing CD's with duct tape but failed miserably because only the paint layer used to stick to duct tape and metal instead stayed on the disk. If I tried to repeat the procedure to remove the metal, the tape tended to tear and leave nasty sticky spots on the disk. Instead I went to a local store that sells blank CD-R/CD-RW and asked them to sell me transparent CD spacers that look a lot like actual CD's but without coating. You can one of these on the left side of the attached picture. They are not usually for sale because these are actually unusable spacers, not actual CD's, but I convinced the shopkeeper to sell 5 of these for like $0.5 which's pretty awesome.</p><p>- The author said that air humidity is important for this machine to work properly. Well important it is! Because when it was raining outside and humidity was about 90-100%, the machine refused to start at all. When humidity was about 80% it barely gave any spark(just 2-3mm). And when humidity dropped to 60% the sparks went to 12-16mm. Interesting, but you cannot tell any difference in air condition - 100% and 60% humidity feels pretty much the same to me.</p><p></p>
<p>superb </p>
<p>Love this </p>
<p>This is awesome</p>
<p>I like this </p>
<p>Outstanding one </p>
<p>This is nice</p>
<p>Can this thing shock something other than the other electrode?</p>
<p>Sure, it is just static electricity. </p>
<p>can you please tell me how does it work or what is a wimsurst</p>
<p>Oh, I thought I explained everything quite good in the intro and step 1.<br>I also gave plenty of links to various other pages with explanations and examples.<br>All I can say is what I have already written down. A Wimshurst machine is just a machine that generates high voltages (static electricity). <br>I'll just refer to wikipedia: (to which I also linked in my text) </p><p>http://en.wikipedia.org/wiki/Wimshurst_machine</p>
<p>Excellent Instructable! it's always nice to see an interesting project that does not take specialty tools or materials. One possible improvement (untested, so be skeptical): if the material you are removing from the CD is already metal, why not just etch/pattern it rather than removing it and replacing it with conductive tape or paint? The material for writeable CD's is not metal so I don't think it's conductive; but music CD's are aluminized and might work. The metal is under the painted label side, so if you left the paint in place it would help protect the very thin metal layer from the brushes.</p>
<p>Thanks!<br>Well, I have read that the reflective layer is usually Silver or Gold spin coated with a lacquer (also for CD-Rs). I tried clearing the CD's by etching it away completely because I thought the layer was aluminium. (I know it's easy to make telescope mirrors with aluminium, so it was a guess, a wrong guess). And that didn't work very well.<br><br>In theory it could work. If you have a way to clear the lacquer that doesn't affect the polycarbonate of the disk itself. And use a better etching fluid than 28% HCL.<br>But then you should remove some of the lacquer on the remaining metal strips since the brushes should get physical contact with the conductive part. (especially when starting up the device). But that metal layer, even with the lacquer is quite fragile. And would be eroded off pretty fast.<br><br>Something easier would be to print the pattern of the strips with some conductive paint. But that would require some more exotic materials which I wanted to avoid.<br>Or even by using a circular PCB into which the pattern is etched. (although that may be more expensive)</p>
<p>excellent for school project. Thanks</p>
<p>You're welcome.</p>
<p>I would love a video of you making one, even if you must do 4 segments. This is so very very cool, or hot, (as in hot sparks).</p><p>Consider painting or spraying on several layers of shellack or water based varathane (out door type is best), they will stiffen all the card stock.</p><p>Also If you laminate card stock parts use exterior grade wood glue then after cutting us the lacquer. The yellow wood glues will make everything much stiffer. The use of glues and varathanes allows you to sand the parts a but making for less sharp edges. The glues and varathanes also will also stop it from absorbing water s easily, Especially if you coat the open edges. </p><p>If you are going to laminate card stock glue a piece of non rip envelope (tyveck). either in the middle or on the outer edges. It is non conductive and strong and water proof. It is actually sprayed plastic fibers. </p><p>I used all the above in building things when my kids were small. Cool boxes, electromagnetic cranes (no motors), science stuff. As well as a few storage bins for myself. Hope it inspires or helps.</p>
Nice job and very admirable that you put together a working wimshurst machine out of such simple materials! I would like to add something which may help regarding the removal of metal foil from the DVD discs. I have found that all you need to do is apply common duct tape to the disc and then remove the tape... the foil comes right off with the tape without harming the plastic. There was no sticky residue left behind. Note that although the disc became perfectly transparent, there was a rainbow 'sheen' on the disc after the removal of the foil... barely present... but still visible. My multimeter is old and finally quit working, so I could not use as an ohm meter to check for any remaining conductivity... so you would need to do this. If it proves to be an insulator (as I suspect it will) then will have a very easy and non-destructive way to remove the foil from DVD discs! I hope you find this useful! :-)
<p>Hello, thanks for your input. <br>I have tested it out, taken a picture and added it to step 3. (I gave you credit for the Idea of course)<br>It is indeed a far more easier and elegant method than my acid method.<br>The rainbow layer is just a non-conductive coating I presume. I had it too with my acid method. <br></p>
<p>After reading through this again and thinking about it for a while, I realized how easy it would be to create a kit for this if you owned a laser cutter. You have already provided a parts list which you hand cut from paper. If templates were provided, all the pieces could be laser cut from wood or plastic (even the foil tape) and simply pieced together. Sadly I don't have access to a laser cutter, so its just food for thought at this point. Also, I had a thought about your electrodes. Do you think it would be possible to electroplate a ping pong ball for a nice clean spherical shape? Something like this?</p><p>http://www.instructables.com/id/Clean-and-Simple-Electroplating/</p>
<p>First of all, congratulations with winning the vintage contest!<br><br>That is actually an interesting Idea. They are all simple geometric shapes, so making a template of some sort with all the parts wouldn't be much work. <br>I have no experience whatsoever with such equipment. But I will inform with people who do.<br><br>Yes, electroplating ping pong balls should work. Although they are a bit big. But you would have to coat them with a conductive paint. (But then there isn't really a reason for electroplating anymore)</p>
Thanks so much! I was honestly shocked to have won!<br><br> I also don't have much experience with that equipment either, but having lots of instructables with parts I merely have to press download and send to the laser cutter would surely push me towards making the investment sooner rather than later. Good point about the conductive paint too. I think the electroplating would be mainly for extra points for coolness, lol. After seeing the part about removing the cd label part, I think there may be a need for an instructable on various ways to remove these labels.
<p>I've found out there is a fablab with various machines in my neighborhood. It could be a good opportunity for me to check it out.</p>
<p>Hi, great job creating a functioning Wimshurst machine from everyday household materials. To answer gravityisweak's question about a kit: AstroMedia has published a cardboard kit with PMMA diisks diameter 210 mm and sparks up to 50 mm long (see here: www.astromediashop.co.uk or www.astromedia.eu). </p>
<p>Thank you!<br>Those are indeed interesting projects they provide. <br>I am actually very impressed by their steam engine. A cardboard steam engine, who would have thought.</p>
<p>This is the first in depth tutorial i have ever found on creating a Wimbhust machine. Wonderful 'Able. You have my vote.</p>
<p>Thank you, I appreciate it!</p>
<p>Very nice instructable. I like that you build it from normal household stuff! Makes me want to build one too :)</p><p>Any idea what voltage is reached? (suppose that depends on the width of the spark gap)</p>
<p>Thank you.<br>Yes, without problems, you can reach a spark gap between 1 and 1.5 cm (so, 30 000 to 45 000 V) But on good dry days with clean disks, you can go with some effort a bit over 2 cm ~60 000 V</p>
<p>This looks fun! I like how you laid out the steps and made links to them in the intro. Also the generator has an old timey style, I might take a crack at making it from wood and giving it a victorian steampunk makeover.</p>
<p>Excellent Idea.<br>In the intro (at the bottom) I refer to an instructable of a person who has built a big one out of wood. : </p><p><a href="http://www.instructables.com/id/Whimshurst-Generator/#step0" rel="nofollow">http://www.instructables.com/id/Whimshurst-Generat...</a><br><br>Also, no need to make a Victorian Steampunk makeover, they already are as Victorian as can be: </p><p><a href="http://www.museumofvictorianscience.co.uk/images/main800.jpg" rel="nofollow">http://www.museumofvictorianscience.co.uk/images/m...</a><br></p>
<p>Very interesting and detailed instructable, thanks for sharing it. <br><br>Near 1958 I restored a Wimshurst machine from my secondary school. The worst part were the discs, they were a little curved. I put them at the sun a while between two pieces of glass, but the method was not very effective. The machine worked awesomely. </p><p>One thing that struck me was that the aluminum sectors were <strong>painted</strong>, not solid aluminum.</p>
<p>Thank you,</p><p>Yes, I have seen your reaction on Badjer1 his instructable. <br>And I have indeed read that aluminium/silver paint is used. But my bristles are a bit too sturdy and the paint would have been scraped off fast. <br>I think paint is used because it can be applied very fast with a template with holes placed over the disk.<br>But I like to limit myself to the challenge of using everyday common materials.<br></p>
<p>Wow !! An awesome project!! Specially I could not afford to cut down woods to build Wimshurst Machine,, but now I see I can use cardboard!! Awesome!! Thank you so much for sharing and keep up the good work!!</p>
<p>Thank you!<br>Well, the same applies for me.</p>
<p>Absolutely amazing!!! I wish I had time to build one of these!</p>
<p>Thank you!<br>I have just seen your cardboard cryptex on your page. You definitely have the skills. It's just cutting out a bunch of circles. <br>The thinking part of the materials and the design took more time than the actual build.</p>
<p>Awesome job.</p><p>I like the way you use gifs to show it working, but is there any chance of an actual video, so we can hear the crack of the spark?</p>
<p>Ah, but next to the button to upload a video fragment, there was written: &quot;Coming soon!&quot;. So I went for a gif since I didn't want to make a youtube account just for 10 seconds of footage. (I have more footage, but it is wobbly, noisy and I sneezed a lot)<br><br>But I remembered that you could just upload it as a file.<br>So, it is uploaded in the last step. The crack is basicly as loud as the volume of your computer, there is not much &quot;sound reference&quot; in the footage.</p>
<p>Ah, if you just paste a YouTube link into the text, the editor automatically embeds it for you!</p>
<p>*whistle* This a very detailed explanation of a very cool project. Thanks for sharing!</p>
<p>Very glad to hear that!<br>Thank you! <br></p>

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Bio: I work with optics.
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