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Small Wimshurst generator from cardboard and CDs

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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From it's development ~1883 it superseded other devices such as the "Holtz" and "Voss" machines.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The Wimshurst machine got superseded around 1924 by more practical generators like the Marx generator which is still used today in laser printers and CRT television (Although those are getting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

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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:

http://www.coe.ufrj.br/~acmq/electrostatic.html

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.

 
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jcomtois24 days ago

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.

Sparticles (author)  jcomtois24 days ago

Thanks!
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.

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.
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.

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.
Or even by using a circular PCB into which the pattern is etched. (although that may be more expensive)

agis6826 days ago

excellent for school project. Thanks

Sparticles (author)  agis6826 days ago

You're welcome.

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).

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.

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.

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.

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.

can you please tell me how does it work or what is a wimsurst

Sparticles (author)  miniscientist26 days ago

Oh, I thought I explained everything quite good in the intro and step 1.
I also gave plenty of links to various other pages with explanations and examples.
All I can say is what I have already written down. A Wimshurst machine is just a machine that generates high voltages (static electricity).
I'll just refer to wikipedia: (to which I also linked in my text)

http://en.wikipedia.org/wiki/Wimshurst_machine

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! :-)
Sparticles (author)  FirstExpressions27 days ago

Hello, thanks for your input.
I have tested it out, taken a picture and added it to step 3. (I gave you credit for the Idea of course)
It is indeed a far more easier and elegant method than my acid method.
The rainbow layer is just a non-conductive coating I presume. I had it too with my acid method.

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?

http://www.instructables.com/id/Clean-and-Simple-Electroplating/

Sparticles (author)  gravityisweak28 days ago

First of all, congratulations with winning the vintage contest!

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.
I have no experience whatsoever with such equipment. But I will inform with people who do.

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)

Thanks so much! I was honestly shocked to have won!

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.
Sparticles (author)  gravityisweak27 days ago

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.

astromatz27 days ago

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).

Sparticles (author)  astromatz27 days ago

Thank you!
Those are indeed interesting projects they provide.
I am actually very impressed by their steam engine. A cardboard steam engine, who would have thought.

This is the first in depth tutorial i have ever found on creating a Wimbhust machine. Wonderful 'Able. You have my vote.

Sparticles (author)  RocketPenguin27 days ago

Thank you, I appreciate it!

binarybug28 days ago

Very nice instructable. I like that you build it from normal household stuff! Makes me want to build one too :)

Any idea what voltage is reached? (suppose that depends on the width of the spark gap)

Sparticles (author)  binarybug28 days ago

Thank you.
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

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.

Sparticles (author)  gravityisweak28 days ago

Excellent Idea.
In the intro (at the bottom) I refer to an instructable of a person who has built a big one out of wood. :

http://www.instructables.com/id/Whimshurst-Generat...

Also, no need to make a Victorian Steampunk makeover, they already are as Victorian as can be:

http://www.museumofvictorianscience.co.uk/images/m...

rimar200029 days ago

Very interesting and detailed instructable, thanks for sharing it.

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.

One thing that struck me was that the aluminum sectors were painted, not solid aluminum.

Sparticles (author)  rimar200029 days ago

Thank you,

Yes, I have seen your reaction on Badjer1 his instructable.
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.
I think paint is used because it can be applied very fast with a template with holes placed over the disk.
But I like to limit myself to the challenge of using everyday common materials.

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!!

Sparticles (author)  argha halder29 days ago

Thank you!
Well, the same applies for me.

comsa4229 days ago

Absolutely amazing!!! I wish I had time to build one of these!

Sparticles (author)  comsa4229 days ago

Thank you!
I have just seen your cardboard cryptex on your page. You definitely have the skills. It's just cutting out a bunch of circles.
The thinking part of the materials and the design took more time than the actual build.

Kiteman29 days ago

Awesome job.

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?

Sparticles (author)  Kiteman29 days ago

Ah, but next to the button to upload a video fragment, there was written: "Coming soon!". 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)

But I remembered that you could just upload it as a file.
So, it is uploaded in the last step. The crack is basicly as loud as the volume of your computer, there is not much "sound reference" in the footage.

Ah, if you just paste a YouTube link into the text, the editor automatically embeds it for you!

*whistle* This a very detailed explanation of a very cool project. Thanks for sharing!

Sparticles (author)  MsSweetSatisfaction29 days ago

Very glad to hear that!
Thank you!