%5BTesla%5D Instructables - Build a 15000rpm Tesla Turbine Using Hard Drive

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Build a 15,000 rpm Tesla Turbine using hard drive plattersby sbtroy on May 25, 2006

Table of Contents

intro: Build a 15,000 rpm Tesla Turbine using hard drive platters .......................................................................... 2

step 1: Make ventilation holes in the platters ......................................................................................... 3

step 2: Make or reuse spacers ................................................................................................... 3

step 3: Make the shaft ......................................................................................................... 4

step 4: Make collars ........................................................................................................... 4

step 5: Rotor assembly ........................................................................................................ 5

step 6: Make the chamber ...................................................................................................... 5

step 7: Make the side panels (stators) ............................................................................................. 6

step 8: Assemble everything .................................................................................................... 7

step 9: Complete turbine and movie ............................................................................................... 8

File Downloads ............................................................................................................. 9

Related Instructables ........................................................................................................... 10

Advertisements ............................................................................................................... 10

Customized Instructable T-shirts ................................................................................................ 10

Comments ................................................................................................................... 10


intro: Build a 15,000 rpm Tesla Turbine using hard drive plattersHere's a project that uses some of those dead hard drives you've got lying around.

In the Tesla Turbine, air, steam, oil, or any other fluid is injected at the edge of a series of smooth parallel disks. The fluid spirals inwards and is exhausted throughventilation ports near the center of the disks.

A regular blade turbine operates by transferring kinetic energy from the moving fluid to the turbine fan blades. In the Tesla Turbine, the kinetic energy t ransfer to theedges of the thin platters is very small. Instead, it uses the boundary layer effect, i.e. adhesion between the moving fluid and the rigid disk. This is the same effect thatcauses drag on airplanes.

To build a turbine like this, you need some dead hard drives, some stock material (aluminum, acrylic), a milling machine with a rotary table, and a lathe with a 4 jawchuck.

Wikipedia has a good review article (http: //en.wikipedia.org/wiki/Tesla_turbine), as well as articles aboutNikola Tesla (http://en.wikipedia.org/wiki/Nikola_Tesla),the boundary layer effect (http://en.wikipedia.org/wiki/Boundary_layer),and Reynolds number (http://en.wikipedia.org/wiki/Reynolds_number)(which determines if the fluid flow is laminar or turbulent).

I run my turbine on compressed air (40 psi), and it easily reaches speeds of 10-15,000 rpm. While the speed is high, the torque is low, and it can be stopped with yourbare hand.

I have more details on my webpage (http://staff.washington.edu/sbtroy/turbine/turbine.html).

UPDATE (27.MAY.2006):

I have a video on my webpage now. I t's a 22 MB DivX .avi file. I couldn't get the link to work properly, so go to my webpage above and scroll to the bottom.

NOTE: As of 25.October.2006 I lost my student webpage. I have moved everything to http://staff.washington.edu/sbtroy/

Image Notes1. After spiraling inwards, the fluid passes through these vent holes.2. The fluid of choice is injected through these ports. By adjusting the relativepressure between them, you control the rate and direction of rotation. I only haveone port on my design so it can only spin in one direction.


step 1:Make ventilation holes in the plattersStep 1 should probably be to disassemble some hard drives but I assume that if you read Make, you've already figured out how to un- Make a hard drive.

The easiest way to make vent holes in the hard drive platters is with a milling machine and a rotary table. Center and clamp a stack of several platters to the rotary tableand then you can cut any radially symmetric pattern fairly easily. Just be sure that you use aluminium platters because ceramic platters will shatter when you drill intothem.

I made two sets of platters; one with a radial array of holes, and one with radial arcs. The platter with radial arcs in the picture was on the top of the stack and took themost damage. The platters beneath it have very l ittle tear-out and look much better.

Image Notes1. The platters beneath this top one didn't have this tear-out.

step 2:Make or reuse spacersThe ideal spacing between the platters depends on several variables including the f luid viscosity, velocity, and temperature. You could go through the calculations(http://en.wikipedia.org/wiki/Navier-Stokes_equations) and make a set of spacers, or be lazy and just reuse the spacers from the disassembled hard drives.

I was lazy and reused the spacers that were originally in between the platters. The advantage to this is that they'll have the same inside diameter as the platters. They'reabout .050" thick where the ideal spacing is closer to .012" but the increased distance doesn't make that big a difference in this case.


step 3:Make the shaftThis is just a piece of aluminum stock turned on a lathe. The center diameter is about .98" (which is the inside diameter of the platters) and about 1.77" long (so it will fit ina piece of 2" thick acrylic).

The thinner sections on each end are turned to fit the ball bearings I pulled from a box of scrap.

step 4:Make collarsThe collars are made from more aluminum stock are wider versions of the platter spacers. The inside diameter is also .98" but they're about .3" thick to hold a #10-32 setscrew.


step 5:Rotor assemblyCenter the platters, spacers, and collars on the shaft and tighten the set screws to hold everything together. I used 11 platters, and 10 spacers. Try to l ine up all of theventilation ports. If there isn't enough tension between the two collars, the platters can rotate around the shaft instead of with it.

step 6:Make the chamberThis is a 4.75" x 4.75" x 2" piece of acrylic that was bored out on a lathe using a 4 jaw chuck. The intake hole is taped for a 1/4" pipe fitting and all of the other holes are1/4 - 20.

I used acrylic because it's what I had around and because it's going to be used for lecture demonstrations. You can use metal or even wood. However, if you plan to usesteam instead of compressed air, wood might expand too much.


Image Notes1. Air flows in through this port causing the rotor to spin clockwise.

step 7:Make the side panels (stators)The side panels are 4.75" x 4.75" x 0.47" acrylic with untaped .25" holes to screw to the main chamber. The center hole is 0.6" and the counterbore is 0.28" deep.

The two 0.6" holes (one on each side) are the ONLY exhaust ports. The air spirals inwards across the face of the platters, through the ventilation ports, around the airspaces in the bearings (2nd picture), and finally out through these two holes.

However, more exhaust holes in the side panels might improve efficiency.


step 8:Assemble everything


step 9:Complete turbine and movieI couldn't get the link to the movie to work so go to my webpage (http://staff.washington.edu/sbtroy/turbine/turbine.html) and scroll down to the very bottom.

Please post (or email me) any questions or comments and I'll do my best to answer them.

Thanks for reading,Steven


Image Notes1. 1/4 - 20 socket head cap screws with plastic thumb screw knobs.

File Downloads

Turbine_CAD.dwg (70 KB)[NOTE: When saving, if you see .tmp as the file ext, rename it to 'Turbine_CAD.dwg']

Turbine_CAD.pdf (22 KB)[NOTE: When saving, if you see .tmp as the file ext, rename it to 'Turbine_CAD.pdf']


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Comments

50 comments Add Comment view all 161 comments

Steam Head says: Oct 27, 2008. 9:10 PM REPLY

How would steam be as a motive power? That would give the turbine some extra "grunt" I would think. Fantastic Instructable.

IceCadavers says: Oct 26, 2008. 3:01 PM REPLY

I might have missed something here, but I don't think I've seen any suggestion of using this type of turbine in a Stirling engine? That's essentially the conceptIamdenteddisk was referring to, an engine that uses the heating and cooling of fluid (and thereby expansion and contraction of said fluid) as anextremelyefficient source of mechanical energy. The difference is that Stirling engines move a piston, not a turbine... anybody more educated in these things know ifthis could be more or less efficient than a piston?

iamdenteddisk says: Sep 8, 2008. 9:57 PM REPLY

hi luke luck and all you tesla turbine viewer's I wanted to post an idea I had about the turbine being used in a free energy project I would love to build one butcant afford it or a copyright of my idea but here it goes.. are you familiar with the hand boiler or love meter? ifso we need to try piping one of them in largescale to the turbine A worthy experiment Im sure someone who has a prebuilt turbine can do. I attach a picture of the boiler and P.S the colored liquid ismethanol or comercial grade alchohol available as dry gas at the auto parts Im all about free energy and a thermal fuelless engine sound like a winner tome..iamdenteddisk@yahoo

Suarve says: Sep 24, 2008. 10:19 AM REPLY

iamdenteddisk - I can see where you're going with this - check this out

http://www.youtube.com/watch?v=aQmfRNzLNQs

I think this is the type of thing you are on about? by using the cooling properties of even just a slow moving body of water you should be able to get themethanol shooting around the tesla turbine...


iamdenteddisk says: Sep 8, 2008. 10:19 PM REPLY

se both my first and second post, if the methanol boiler eperiment is a success then my next offering would be to connect this dc motor via a sleeve andsetscrews and you have a high voltage dc genorator or add the charge controler to have a thermal electricity genorator add some black paint a parabolicmirror and insulate here and there you got a marketable and patentable product for the masses ...P.S im a physics guru and would love to colaborate on thisproj if any takers!iamdentededisk@yahoo

wjbombo says: Apr 14, 2007. 9:47 PM REPLY

Could you combine this with a magnetic alternator as an input to create electricity?

wjbombo says: Apr 14, 2007. 9:57 PM REPLY

To be more clear, could this tesla turbine spin a platter of permanent magnets (like the windmill projecthttp://www.instructables.com/id/EDTMO3QLQIEP287OGM/ ) and extract the energy (some of which could power the air pump) ?How many watts is that air pump using in this experiment?

wjbombo says: Feb 29, 2008. 9:03 PM REPLY

Someone please show me where I asked for anything in violation of the law of conservation? I specifically asked what the energy usage was todetermine how efficient this electrical generator could be... given the setup I describe. If there is a very limited loss of energy and this is highlyefficient, isn't it worth considering looking into to determine if could be a better alternative to coal, oil and other old energy technologies currently inuse?So the original question remains unanswered... How many watts is that air pump using in this experiment?Peace.

allElectrick says: Sep 5, 2008. 9:01 AM REPLY

your 100% right

wow-amazing says: Jul 28, 2008. 7:57 PM REPLY

Tesla turbines and electric generators are very efficient. If you where to power an optimized turbine driving an optimized generator, you wouldonly lose about 15% of the original input energy. That wouldn't be a bad idea for a power plant.

Full Frontal Graphic says: Apr 1, 2008. 2:22 AM REPLY

I think they are objecting to:"extract the energy (some of which could power the air pump) "

because the air pump is providing the force that turns the turbine,the air pump, no matter how efficient, cannot run on the amount of energy this puts out if the only input power to the turbine comes from the airpump.

it would be similar to the perpetual motion machine where falling water turns a wheel that lifts the water...

or a generator that charges a battery that runs the generator

or using hydrogen power to crack water into hydrogen and oxygen

or a clock that uses a pendulum and fall ing weight to raise the fall ing weight one notch each time it falls one notch

or a photovoltaic panel powering a lamp that shines on the panel and creates electricity to power the lamp

or using steam power to to generate electricity and then using the electricity i t produces to run the electric heating coil that heats the boiler toproduce steam

or a city where streets are one way in alternating directions, and the streets are all downhill, so you can coast your bicycle downhill wherever yougo

or a fan powering a windmill that generates electricity to power the fan

...

sorry, I'm not being nasty, just providing a bunch of examples so you can pick one that's the most understandable.

all of those "violate" a principle of physics (specifically thermodyanmics) that is called "the Law of Conservation of Energy" . Nobody is accusing


you of anything criminal.

kscience says: Jun 29, 2008. 2:39 PM REPLY

Ah yes, the laws of physics. Elegant, repeatable. Not like the fools errands we live with daily"laws" produced in the congress and senate, orby executive order..... ;>)


"or using hydrogen power to crack water into hydrogen and oxygen" ... and using the resulting hydrogen to power the "hydrogen cracker"

cholo71796 says: Apr 24, 2008. 7:10 PM REPLY

Sir, I think you've misunderstood Wjbombo. The way I viewed his comments states that he is curious as to, if possible, go aboutharnessing the energy created by the turbine and using it to power some of the turbine. See, here he says "and extract the energy (someof which could power the air pump) ?"

darthdavid says: Apr 23, 2008. 4:44 PM REPLY

You're thinking of the Second Law of Thermodynamics, which states that over time the total entropy of a closed system can only increase.In basic terms, nothing is perfectly efficient so unless you have external input of energy to a system it will wind down or become moreentropic.

i make shooting things says: Feb 29, 2008. 6:59 PM REPLY

the law of conservation of energy states that energy can not be created or destroyed; when ever there is movement friction with air or other object iscreated this causes heat which "waist energy " or at least it cant efficiently be returned to the system. This is why perpetual motion is impossible.

harleyloaf says: Mar 6, 2008. 11:08 PM REPLY

Actually the law of conservation of energy states that energy can not be created or destroyed, it can only be changed from one form to another.e.g. friction turns kinetic energy into thermal energy.

James (pseudo-geek) says: May 7, 2007. 1:32 PM REPLY

sorry, but that idea doesnt work. you cant get more power out of something than you put in......... . unless its that one guys experement withalternating magnets....I'de have to go get the stuff out of my room to show you and I'm too lazy.

holomorph says: May 9, 2007. 6:13 PM REPLY

But you could run the turbine off steam rather than an air compressor.

James (pseudo-geek) says: May 9, 2007. 6:42 PM REPLY

I think you missunderstood his point. I think hes trying to make a prepetual motion machine.

The Fallen says: Dec 20, 2007. 11:37 PM REPLY

that's kinda impossible, but still cool to see how far people can get on those machines

craz meanman says: Feb 29, 2008. 2:50 PM REPLY

it is impossible. you can make things like perpetual motion machines but energy is always slipping away and into different forms...

James (pseudo-geek) says: Dec 21, 2007. 4:26 PM REPLY

agreed

Car Dude says: Mar 9, 2008. 2:39 PM REPLY

know what I've been thinking... a really good perpetual motion machine is, a hydrogen car, water in, water out. you know, with theelectrolysis process and all. the exhaust is steam. so it should work...

Dungeonbrownies says: Apr 2, 2008. 9:48 PM REPLY

lol, good one



yeah yeah it's just water...

but think how expensive water would become if we used that idea.

;-)

-Aj- says: May 10, 2008. 11:34 PM REPLY

only prob is theres a bundle of energy lost in the mean time.youd need to split the water into hho first. which requires energy. if done inside the car then solar or something. inwhich case whats the point of the hydrogen part at all?powering a car on hydrogen, hho or batteries is only an alternative storage medium as opposed to petroleum. if yourusing a coal power station to extract hydrogen or to charge the batteries then theres no point because the coal powerstation is still producing the greenhouse gases the car would. (although they are more efficient then a car, so take thatinto account)

splart says: Aug 26, 2008. 8:27 AM REPLY

Great project!!..................Now give us all a list of green recycle sustainabilty applications for this baby using ...say compressed air ...or whatever.This would make it all the worth more while.

b-train says: Apr 21, 2008. 9:24 PM REPLY

hi i am sorta confused with the idea of tesla turbines, i understand how and y they work but not y you wld want to build ur own mini tesla turbine, wat wld uuse it for? is it more of a novelty thing or do u guys power stuff fans n stuff from water hoses? thanks


It's mainly a novelty, but it would be and interesting project to turn into a high powered fan.

MY says: Jun 29, 2008. 11:34 AM REPLY

Tesla's bladeless turbine design is an excellent method of converting fluid momentum (water, steam, compressed air) into rotational force which candrive motors, generators, etc. If PROPERLY designed (both rotors and nozzle) it's efficiency rivals far more expensive designs such as the steam turbine. That's the beauty of the Tesla Turbine...the elegance of it's simplicity. For more info you might consider joining theTesla Engine Builders Assn.

bedeboop says: Jul 26, 2008. 3:23 PM REPLY

At the risk of offending...could I, at home, use this somehow???? I read about making the Tesla...just not sure why I would make one at home and if it has apractical use for home I would love to know.

tater_3001 says: Jul 16, 2008. 11:36 AM REPLY

if you were to add a connecting piece to connect the platters like a water wheel except in a spiral fashion down the spindle, would the platters move fasterand create more energy?

kscience says: May 1, 2008. 7:47 PM REPLY

This is a great proof of concept piece; however, in the Tesla Turbine book f rom Lindsay Publications I had, the one he built was 100 lbs, and 10 hp. Thediscs were some nickel silver alloy and were quite heavy. This was for a reason; it is important in a motor to have a flywheel, to gain some moment of inertia,a way to store the energy. HD disks are perfect for demos but no energy is stored in them over time, sadly. But you can run em on a desktop or feel theirgyroscopes in your hand. The guy holding the original turbine for the photo did not look happy about it...

a sort of "exponential horn" in reverse between the circular tubing input to a uniform slot covering all the discs in the stack would certainly up the efficiency aswell.

MY says: Jun 29, 2008. 11:50 AM REPLY

As others have already said, Tesla's claim was 10hp per pound, but to your point about the necessity of a flywheel - Tesla himself arrived at that sameconclusion as is evidenced in his last patent application. His submission to the British patent off ice clearly shows the addition of thicker outermost discs,tapered inward. The central star washer/hub and cross-plate rivets can be disregarded as they were clearly attempts to work around imprecisemanufacturing equipment and inadequate raw materials. Tesla was so far ahead of his time that most people are still not aware of his contributions. Hetotally spanked Thomas Edison on many issues (Tesla often derided Edison's brute force techniques as wasteful and unnecessary). In fact, Tesla wasan Edison employee until he couldn't stand the close mindedness any longer. I believe their falling out was over Tesla's idea that AC current was thewave of the future, while Edison and his team remained sold on DC. Look it up for yourself - it's fascinating reading.

tdbrady says: Jun 30, 2008. 10:15 AM REPLY

The "falling out" was caused when Edison refused to pay the $50,000 bonus he promised for a performance design improvement on one of Edison'sdesigns. Tesla promptly resigned when refused payment.


kscience says: Jun 30, 2008. 11:21 AM REPLY

Sigh; some things just don't change. George Westinghouse continued the tradition of ripping Tesla off as well, ignoring his ideas thatWestinghouse wanted to keep down, as his tooling was already making him rich with his existing machines......


And while the ruthless Edison did Animal Experiments to try to discredit Tesla, whose power runs our grids worldwide today? The most efficient one,which happens to be the easiest and cheapest to scale. Viva Tesla...!

wow-amazing says: Jun 4, 2008. 6:19 PM REPLY

That's strange, nine times out of ten, I've read that Tesla's turbine produced ten hp per pound, but you could be right. Also, the tesla turbine didn't need aflywheel because it was self starting and had significant torque at zero rpm's, so the only real requirement for the disks would be that they're strong. Icould be totally wrong, but that's from my experience.


Umm, if anything in physics allowed us 10hp per lb, or 7500 watts per pound, I imagine we'd be using it. Its amazing what is on the Internet that getsread, spread, and believed. There are books out on Tesla's turbine. They tell a truer history than suggesting 10hp/pound. Solid fuel rockets maybe.Google turbines to see that they are fast, not torquey. The STP indy turbine car needed a huge transmission....!

Finally, the Tesla turbine is a flywheel, really, isn't it? A distributed one, but it is a wheel that flies on its bearings. Big enough to store energy, if notmade of hard discs.


You'd think so, huh? Yeah, this is everywhere. Have you ever read a 60 year old book talking about the tesla? And yes, I know turbines aren'ttorquey, but relatively, the tesla is pretty torquey. BTW, tesla turbines can very easily be over 90% efficient because of the way the energy istransferred to the disks, and gasses moving at the velocity they are out of a jet engine have quite a bit of energy. To answer your last question,no, a tesla turbine isn't just a flywheel that stores energy. The amount of energy you could store in a flywheel is minimal and hardly usable. Alsoas a side note, you'd use hydrostatic transmission instead of a mechanical one to reduce the speed.

bwcbwc says: Jul 26, 2008. 2:12 PM REPLY

How would you scale up the model to increase the torque without increasing the weight too much? Presumably an air pressure increasewould be required to provide the additional energy, but would you get more torque per mass from larger-diameter disks (anyone have someold 12" laser video disc around?) or by adding mult iple channels of airflow and multiple pairs of disks along a shaft?


Powerful tesla turbines spin so fast that gearing them down to a reasonable speed produces incredible amounts of torque (for their sizeand weight).

kscience says: Jul 27, 2008. 9:47 PM REPLY

Its been years since I heard about the magnetic power transmission developed in the northwest; I suspect it was bought up by thiscompany-

http://www.dextermag.com/MagneGear-RMG.aspx

google keeps leading me to this site. Magnetic transfer is more efficient than friction laden gears, though, it seems. So do not neglecttrying this newer way of speed reduction/torque magnification....

kscience says: Jul 27, 2008. 9:24 PM REPLY

Thank you, wow-amazing. This is so true. There is also magnetic coupling, as is being manufactured in Port Townsend Washington,which is more efficient than gearing.

Still, Tesla made his turbines to run on highly viscous fluids, like Steam, not Air! If air is all you have, compressed and frigid, at leastinput it with a venturi to mix it with ambient temperature air to get some modicum of condensation...! Its still not as good as steam formotive transfer but its better than cold dry air......


I think part of the reason why tesla turbines are so genius is because of their versatility of compatible powering fluids. The teslaturbines' design could be optimized for use with all sorts of fluids, which made the turbine very efficient and powerful. BTW, themagnegear is a very good idea, and one that I have had recurring thoughts on as how to incorporate that with a tesla turbine.

rainCheck says: Jun 27, 2008. 4:24 AM REPLY

ANY spining disk is a flywheel



But often times can't store enough energy as to be practical, which kscience claimed.


Sort of like in old vacuum tube amps with old filter caps; they not only filter out the 120hz hum, they store the energy the amp needs todeliver power chords and hard stacatto notes. Old caps are analogous to an internal combustion engine whose big flywheel is now thesize of a glazed donut.

Having said that, the Turbine has most of its power in the Velocity term ofsquarede=mc; Traditional engines have it in the mass term,or the flwheel, crankshaft, etc. This is why I try to distinguish that torque is not a relevant term to use with turbines. Torque will beavailable with a radical reduction scheme to yield lower rpms, though.


e=mc2 may read better; the squared was in parentheses after the formula when I entered it........

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%5BTesla%5D Instructables - Build a 15000rpm Tesla Turbine Using Hard Drive