Instructables
Picture of Build an Amazing Tesla CD Turbine
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Build a real working turbine from recycled CD's!

This Tesla CD Turbine is based on the Tesla turbine, which was invented by Nikola Tesla in the early 1900's.

Tesla's pumps and motors were unique in that they only used discs, and took advantage of the boundary layer effect. His smallest designs were over 100 horsepower.

This Instructable is an introduction to my recently developed Tesla CD Turbine, which is made from CD's, CD spindle, pipe fittings and glue. This easy beginners version runs on garden hose pressure and is fun for demonstration or experimentation purposes. This same CD Turbine can also be powerful, versatile, useful and dangerous when used with compressed air pressure.

The basic model Tesla CD Turbine shows how the boundary layer idea works to deliver power. The CD Turbine has unique design features such as no moving shaft, no bearings, no seals and uses recycled CD's. It is so frictionless that it can go over 500 rpm just by blowing into it hard!

The advanced model has many cool features, such as the use of neodymium magnets to separate the CD's with the correct gap and a Magnetic Coupler to attach implements, and much more.

My next CD Turbine Instructable shows how to make a Magnetic Disc Pack and Magnetic Coupler for more advanced CD Turbine experimentation. I will develop magnetically-coupled implements that will range from the practical (Generator, SaladSpinner, etc.) to the bizarre ( Skilsaw Blade , Punch Bowl Stirrer, etc).

However, please be forewarned that this turbine on air pressure is not really a kid's toy or particularly safe to operate.
On water pressure it is safe from explosion, maxing out at about 1000 rpm.

The turbine can be run on either water and air pressure without modification. Although this simple turbine can be safely run at one or two thousand rpm on water hose pressure, it can turn tens of thousands of rpm on air pressure.

I must warn you running this turbine on air pressure could be enough to explode the CD's in the turbine and cause injury. To prevent this, regulate the air supply to lower the psi and use a digital tachometer like this one.

If this unit is run on air pressure, precautions must be taken such as protective gear (heavy leather gloves, face shield, helmet, leather jacket & pants, cup(?), etc.), as well as being behind a protective barrier. If the CD Turbine comes apart at 25,000 rpm, sharp CD parts will be impelled literally at the speed of a gun. You are forewarned!

I will be discussing ways to avoid any possible unpleasantness as we go along in these Instructables, but for now...let's have some FUN!
 
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beboms1235 months ago

Hi, can you tell me how to connect the turbine to produce electricity? My email is beboms123@gmail.com. Thank you.

Samalex675 months ago

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powersourcez9 months ago
Mr.Fix i am new to instructables and because of my investigatory project in physics,this particular experiment caught my eye,but i want to power this by compressed air so my question is can you suggest other cheap sources of compressed air?also can i use a bike pump?advance thx for the answers :D
mrfixitrick (author)  powersourcez9 months ago
I have powered my CD Tesla Turbines with everything from my breath ,to compressed air and water combinations. Compressed CO2 can be used...carefully. An air compressor is safest and reliable. Use up to 90 psi...carefully! The bike pump will work for a good demo. The nozzle size going in to the turbine is important, and the more friction-free the discs are, the faster it will go.

A couple of times, I "borrowed" compressed air from a gas station into my 5-gallon tank. I then ran the turbine at home (briefly), with the "free energy" !
badmoonryzn11 months ago
Why do you have so many disks when the water only hits a few of them? I do not understand what you are doing I guess. What are you using as a bearing for the disk pack that rides on the spindle? It looks pretty cool and tesla is one smart cookie, so he had something going on. Since there are no blades does the turbine just rely on friction against the disks? I know lots of questions. I think you did a great job on using a disk case and disks. What a great idea. Thanks for the video.
regards'
Den
mrfixitrick (author)  badmoonryzn11 months ago
Hi Den, Hehe, yes lots of questions! ;)

Many discs work well in my case, because when fluid exits the nozzle and hits the discs, it spreads immediately into about a 45 degree angle and covers most of the discs in the spray pattern. Besides, the sheer momentum of the fluid vortex helps pull the other discs at the ends along.

There are usually no bearings in my turbines, as the discs use hydrodynamic bearing principle and are free-floating above about 2000 rpm. The central spindle helps keep the discs centred at the beginning.

Tesla said that his turbine did not rely on friction, but on adhesion and viscosity of the fluid on the discs instead.

Read the Tesla patents and this wiki description to get more of an understanding of this amazing idea from Tesla… http://en.wikipedia.org/wiki/Tesla_turbine
Zem5 years ago
Is it just me, or in the second picture is there an Alternator connected to it?
mrfixitrick (author)  Zem5 years ago
Well it's about time someone noticed! Hehe Yes, that is correct. I adapted a magnetic coupler to an automotive 12 volt alternator, and got it to rotate by magnetic coupling with the turbine. With faucet water pressure at only about 30 psi, the set-up was not effective. I could not get more than 50-100 rpm out of the turbine/alternator, and so could not get more than a few millivolts out of it. I think it would generate power if it had 60 - 80 psi water pressure to work with.
how would you set that up?
mrfixitrick (author)  seamaas4 years ago
To set up the alternator I simply attached a magnetic coupler to the alternator shaft, then used a coffee can as an adapter to fit the turbine. The magnetic coupler was made with 6 of 1/2 inch neos as drive magnets sandwiched between two CD's. The drive magnets of the turbine repel the magnets of the coupler, and they move as one unit. I did not have enough faucet water pressure to make theTesla Tturbine Alternator go very fast, and only got a few millivolts out of it. With adequate pressure of 70 to 100 psi or more, it would likely generate good power...until the turbine case splits open, that is!!
If your getting a few milivolts out of it, it is working, but you havent connected it right. i have recently been using alternaators on gas lawnmower engines, and i know the alternator should produce useful power at 100rpm. there is a third wire coming out of the alternator (not the power output). that wire must be connected to +12v to work. the alternator has no permanent magnets in it. intead, it has an electromagnet that rotates in the alternator windings. this electromagnet is powered by the +12v third wire, so if there is no 12v, there is no magnetig feild, and only a few milivolts are made. (the reason for the electro mag intead of permanent is that the internal regulator can restrict power to the electro mag at high rpms to make it weaker at faster speeds, and thereby regulate the alternating voltage produced. then an internal rectifieer converts it to regulated DC) so try it again, and i bet you'll get something. then the electro magnet comes online, it will resist more, so i doubt it will keep 100rpm, but you might get useable voltage! I hope ive helped. i try to do justice to my name, furtherthantesla.
mrfixitrick (author)  FurtherThanTesla4 years ago
Thanks for the instructive comment!

As a mechanic, I've been around alternators for 40 years. Your comments are right on. I applied power to the field wire as you suggested.

The main problem of not generating power was getting the shaft to spin fast enough. The rotating/rolling resistance of the alternator took up most of the energy output of the turbine, while running it at the relatively low pressure of 30 psi or so.
So rpm's are very limited unless pressure can be increased significantly.
Do you think this would work?
Put a nice heavy fly wheel on the alternator, on the pulley for the belt. Connect the Tesla turbine, get it under some water pressure, spin the fly wheel with your hand... I wonder if then the fly wheel and by extension alternator will stay in motion? It seems to keep that fly wheel in motion, should be a lot easier than to fight the resistance of the alternator without it. The standard solution for this though, is to build a more robust alternator, that produces usable voltage at a lower RPM. .Neodymium magnets are relatively cheap considering how much they can be worth in a alternator configuration. It's a couple hundred dollars or so of magnets and less than a hundred dollars of magnet wire, to put together an alternator that works well at low RPM.
mrfixitrick (author)  rocyahsoul2 years ago
Thanks for the question!

The main problem is that you can only get so much power out of faucet water pressure. It may be in the range of one to ten watts. Most alternators will require that much power just to overcome the resistance of the bearings, seals and fan. Then there is the force of the magnetics and back EMF to be overcome in order to actually generate power.

A flywheel can store excess power, or help with the "notching" effect of magnets on coils of wire, but a flywheel will not make the alternator create more power. or keep it spinning. when there is not enough energy supplied continuously.

Using an alternator could work well with higher pressure, say 100-150 psi would be nice, at a good flow of 5 to 20 gallons per minute, and by using a maximum number of discs in the turbine. Otherwise, with my turbine setups, one is limited to a small alternator or generator design by using coils of wire to extract the few watts of power from the rotating magnets.
Okay, cool. i firgure that if you built the turbine and attached the alternator in the first place, you plobly know what you are doing :)

Actually, if your a mechanic, i have an unrelated question. I made pans for an engine a while ago that runs on both diesel and gas using (compressive detonation). I want to make a prototype, but i need to know how much PSI will be generated at TDC right after the plug has fired with the throttle open fully. do youk know within a hundred PSI what that might be? :/ Thank you.
I have a 1948 John Deere Model G that has what they called the "all fuel engine." It will run on anything from gasoline to lamp oil, and I've heard of people who made them run on Vaseline and paraffin with a few modifications. The base part of the design is that the intake and exhaust manifolds are one piece to pre-heat the fuel. It's a two-cylinder engine. They're about six inches in diameter with a stroke of just under a foot. All things considered it's fairly efficient once you get it up to temperature. You could probably look up the design for use as a reference. With modern, computer-controlled ignition and mixture, one could probably squeeze quite a bit more out of it.
and also, would a modified gasoline engine (like a small mower engine) be able to handel those kind of forces?
i just love messing with auto alternators :3
would it not be presumable that if you added a small engine torque converter that it would up the rpms that are being produces
mrfixitrick (author)  Rottom3 years ago
The automotive alternator takes all the turbine power available just to get it moving. Trying to increase the rpm with gearing, without additional pressure from the water supply, is futile. It would be like trying to move your car in 5th gear at an idle.

Additional water pressure will increase the turbine power and rpm's sufficiently to drive the alternator properly.
ok point taken, but could you not design an engagement mechanism for after the turbine was up to speed that way it does not bog the turbine under instant pressure.
mrfixitrick (author)  Rottom3 years ago
The Tesla turbine has a flat torque curve compared to an auto engine that generally has increased torque with higher rpm. If the turbine bogs at low rpm, it will bog at high rpm too. (same torque) The horsepower is greater at higher rpm, but not the torque.

The engagement mechanism you mention might be useful if the turbine was tuned for maximum torque at a specific higher rpm, but usually there would be no advantage (other than flywheel effect) to "spinning up" the turbine first.
seems i need to build one of these to do some testing for myself to see if there is maybe even a gearing system for possibility of more speed with less load... aether way love the challenge.
mrfixitrick (author)  Rottom3 years ago
Be careful...The Tesla Turbine is a deceptively simple device that will give a lifetime of experimenting and learning to those who get addicted!
Zem mrfixitrick5 years ago
=D.

Excellent I was wondering if that was possible.

Ah, well I hope you find a more successful setup!
juanjomf2 years ago
Hey the cd will not drilled?. can you give me a picture to my mail as the magnets are and how you separate the cd? Thanks and forgive my English, juanjomf97@gmail.com
keegan2 years ago
wow, you managed to get it running at 500rpm just by blowing hard? i just built one and it hardly goes at 100rpm by blowing... also, i understand there is supposed to be a gap between the discs - how do you do that? anyway thanks for the clear instructions and pictures!
elmotactics3 years ago
I have no idea as to the feasibility of something like this, but would it be possible to make this into a sort of wind turbine, and then use the magnet discs as a generator? I know that in general small-scale wind turbines have a lot of trouble overcoming the magnetism of the permanent magnets unless there is a powerful wind, so this seems like it would be a lot easier. I was thinking something like having a large, flared intake to maximize air pressure, and then a tail boom to make sure it orients itself with the wind .
I'm been experimenting with wind turbines for about a year now and built a few HAWTS and VAWTS each one improving on the last. I'll do an intructable soon, have been a bit slack.

Funneling just doesn't work with wind turbines, its relates back to the equation that only 59% of wind energy of a given swept area can be harnessed. This is largely due to airs high viscosity, it bounces around and creates turbulence within a funnel, a small amount of funneling will improve performance slightly but large funnels actually make turbines less efficient, as they create drag and turbulence rather than allowing a clean stream of air onto the turbine. The amount of compression you could get with funneling would be minimal at best.

I do however believe that using wind turbines to compress air via a piston or pump is completely feasible and would like to look into doing this myself.
mrfixitrick (author)  wildwabbit2 years ago
The TESNIC wind turbine uses Tesla disc technology. Have a look.
I have seen this video it is quite old and am yet to see this design running in anything other than a controled environment. I think the concept does work but it will only operate effectively in optimum conditions, ie: strong consistant winds.
Not a great deal of practical application, in most real world environments.

If I saw a video of this turbine out doors in a light to moderate breeze, I be more inclined to beleive it has potential. However no such video's exist. I'be made a coupe of lenz2 turbines, with a good degree of success, and recently came across the "canstien" or " c-rotor" which is a variation of the lens 2 design. I plan on building one of identical proportions to one of my. Lenz2's will post an instructable in the near future to compare the two designs.
You can see some of my turbines on my youtube channel wildwabbit74
mrfixitrick (author)  elmotactics3 years ago
There is a company that has recently patented a similar idea! Check out the Tesnic wind turbine here:
http://www.youtube.com/watch?v=Vyvf7iyi-wM
with all the different methods of generating electricity with Tesla's designs, the only thing a patent will do is ensure that mine can't appear to be the same as yours, even if it basically works the same, because the improved application is so obvious to those of us with a good imagination.
i was thinking of the same kind of wind tunnel using a 12V electric motor attached to the spindle to be a generator. here's hoping you figure it out. that's half the fun, isn't it?

:)
.
mexiquinn3 years ago
could you use a water balloon nozzle
mrfixitrick (author)  mexiquinn3 years ago
A water balloon nozzle will likely be too big. The CD Turbine nozzle inside diameter should be no more than about 1/8 inch hole size.
jsimonyan3 years ago
please tell me if im crazy, i want to build one of these cd case turbines but im not sure if my case is the right size, it will hold about 53 normal cds, i measured the removable part of the case to be 3.125 inches tall (3 and 1/8) so factoring in that cds are .053 inches tall(.053x with x being the number of cds) and i need magnets for each layer which are .03125(1/32 inches tall) making the equation .053x + .03125x < 3.125(the height of the cd case) so the number of cds i could fit in (counting magnets) is 37(i rounded down to 35). am i crazy? did i totally mess up the equation??? because i see you with 10 disc turbines and you seem to have the case full, please help, i dont want to buy 5x the amount of magnets i need, they are very expensive :P
mrfixitrick (author)  jsimonyan3 years ago
it helps to be a bit crazy to build one of these. And if you weren't before, you probably will be after!

Your calculations and formulae are good, but there are some hints and important points.

1.) The height of the disc pack is not as critical as it seems. You can use almost any number of discs you wish. From around 6 discs, up to 25 discs, is generally a good number to use.

Understand that if the inlet nozzle is relatively high in the case, the whole disc pack will rise to the top of the case when the turbine is running anyway.

2.) More discs do not necessarily mean more power. The inlet velocity/pressure of the fluid is most important, and the higher speed particles can only cover so many of the discs, depending on volume of fluid and shape of inlet nozzle. 

3.) If the turbine is used with water pressure, the top magnets are usually larger for better magnetic coupling. They stick out, (without a CD on top) to be closer to the top of the case. So you have to add their height to your equation.

4.) The magnets form a bearing surface at the inner top of the case, and skim along barely touching the case when it's running due to the fluid bearing effect. (note: if the turbine is used for compressed air pressure, then larger top magnets can't be used because the rpms are too high.)

5.) The centre post gets drilled for fluid exit. Keep the holes toward the top of the post exactly where the CD's will be rubbing when they rise up to the top under running pressure.

6.) The type of CD case is important, as some of them are virtually impossible to seal properly to be able to build up pressure internally. I use the older Memorex cases with a thick bottom so the hot-glue will hold better.

Good luck and let me know how it goes!

physicsproj3 years ago
Hey there, I just finished making a turbine for a physics project, and i wanted to thank you for the very helpful instructions! It would have taken me much longer, and been much more arduous without your help.
mrfixitrick (author)  physicsproj3 years ago
Thanks much for the positive feedback!

May you continue to ponder the mysteries of the Tesla Turbine for years to come!
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