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!
Step 1: Materials and Tools
MATERIALS LIST: (Total Cost about $10.)
1.) 10 (or more) recycled CD's (no labels & no cracks)
2.) CD Spindle with Cover (recycled)
3.) Orbit WaterMaster Extension Nozzle Model 91129 ( Home Depot, $5.95, or try a $1.80 Nozzle from Holland GreenHouse products.)
4.) 1-1/2 inch of plastic straw or tube to fit small end of Nozzle above
5.) Garden Hose Shut-off Valve ($3.50)
6.) 2 feet or more of 3/4 inch PVC plastic pipe ($.50?)
7.) ABS to PVC cement
8.) PVC Pipe Primer
9.) Methylene Chloride (Plastics Shop), for welding polycarbonate CD Discs to each other.
10.) Hot-glue sticks...less than a half dozen
Dremel Tool (optional)
Notes: 1.) More than 10 CD's may be used for taller CD spindles.
2.) If you can't find the "Orbit Watermaster Nozzle", you could use any plastic or brass water nozzle, such as the Holland GreenHouse brand Plastic or Brass Power Nozzle. Or simply use a combination of pipe fittings down to a 1/8 inch nozzle, and adapt with hot-glue to the CD Cover.
Step 2: Design an Inlet Nozzle for the CD Turbine
This is where the rocket scientist in you comes out...what size, shape and angle inlet nozzle should the CD Turbine have? There will be many theories, but the facts are... WHATEVER WORKS!
I have tried several different types and materials...they all worked. There's room for experimentation here. You just need to taper down to about a 1/8 inch hole into the side of the CD case with pipe fittings, or plastic pipe, then hot-glue it all in. ( Pictures in following step.)
I used an Orbit WaterMaster Extension Nozzle Model 91129 from Home Depot for the Tesla CD Turbine II nozzle. The Orbit Nozzle has an advantage of being able to use a long 3/4 inch PVC or ABS pipe with the included fittings. One fitting is a tapered nozzle, and was originally used for burrowing under concrete sidewalks with water pressure. The other fitting connects easily to the garden-hose Shut-off Valve. A 2' piece(or longer) of PVC connects the two Orbit fittings.
Note: Brass fittings and copper pipe could be used for more of a steampunk look.(future instructable!)
A Later Note: My newer instructable makes the nozzle install process much easier!
Step 3: Fit the CD Turbine Nozzle
Ok let's get started by fitting the Nozzle and its Extender Tube to the CD Case.
Cut the smaller nozzle end of the Orbit Watermaster Nozzle at an approximate angle according to the pictures, so that it sits closer to the CD Case when gluing. Start the hot-gluing by putting a dab on the side of the CD Case and sticking on the Nozzle right away. Keep hot-gluing around the Nozzle, letting things cool a bit as you go, but keep the Nozzle lined up as far as angle and direction, similar to pictures. Leave the area directly in front of the Nozzle free of glue, so that you can cut out the Case to fit an extender tube from the Nozzle into the Case. (See pics.)
A Later Note: My newer instructable makes this nozzle install process much easier!
Step 4: Join a Tube From the Nozzle Into the Case
We need to be able to connect the small hole in the Nozzle into the inside of the Case. Cut a small (1-1/2 inch long) piece tubing that fits the inside of the Nozzle. Cut two slots about 1 inch long into the case in front of the Nozzle. Make them about 1/4 inch apart. (see Pics) Cut at each end of the slots to form a rectangular hole. This hole will accept the extension tube and allow it to go inside the case. Insert extension tube into both Nozzle and CD Case and hot-glue into place. Cut the tube flush with the inside of the Case when the glue is cooled. You should get something like what the pictures below show.
A Later Note: My newer instructable makes the nozzle install process much easier!
Step 5: Finish Nozzle and Attach PVC Pipe
Continue building up hot-glue until the Nozzle and Nozzle Extension are well secured to the CD Case. There should be no glue on the inside of the Case. The Nozzle Extension should have been cut flush with the inside of the Case, giving an oblong shape to the nozzle jet opening. The Nozzle should be well supported by the build-up of glue on the Case by now. Allow the glue to cool.
Now it's time to attach the 2 foot piece of 3/4 inch PVC pipe. Sand each end of the pipe to clean it, then use the PVC primer to prep. Add PVC-to-ABS cement to each fitting and pipe end, and twist together to connect. Let the cement set for an hour minimum. Here's an instructable for more info on cementing PVC.
Attach the Garden Hose Shut-Off fitting to the fitting on the end of the PVC pipe.
The Nozzle and CD Case Cover mods are done!
Step 6: Prepare the CD Spindle.
Drill holes in the CD Spindle as shown. Clean out the holes of shavings. De-burr and polish spindle post with 400 sandpaper or cleaning pad. If desired, install a half-inch barbed garden-hose fitting on the bottom outlet of the Spindle post. This allows a garden hose to be connected to the outlet. This works especially well if the CD Spindle Cover is hot-glued or duct-taped to the bottom lip of the Spindle tray for leak-free operation.
Step 7: Assemble the CD Disc Pack
The CD Disc Pack is the rotating part that is made of CD's. It spins inside the CD Case. There are several options for CD Disc Packs.
The easiest thing to do, is...nothing! That is, just stack the CD's on the spindle post without gluing or using magnets...about 10 CD's in this case. You can use more CD's if the CD Spindle is taller.
Disc Packs can also be built by simply gluing together discs with a few drops of Methyl Chloride (available at a plastics shop). Methyl Chloride is the solvent glue for CD Disc polycarbonate-type plastic. Put the glue on the raised ring, which you can feel near the centre of the CD, to bond each CD to the next. The glue sets fast. Try to keep the Discs centered on the Spindle as they are glued together. A couple of wraps of paper around the Spindle to take up clearance before gluing the discs might help keep the Disc Pack aligned best.
Let the glue set-up and get ready to assemble and test your Tesla CD Turbine!
Install the recently modified CD Case (with Cover and Nozzle) onto the CD Spindle and Disc Pack. Make sure the Disc Pack spins freely on the Spindle and in the CD Case. Hook up the water pressure supply, adjust the water pressure with the Shut-Off Valve, and the CD's should start to go around!
The speed of the CD Disc Pack is dependant on the water pressure, controlled by the garden hose shut-off valve. It should be able to go over 1200 rpm on garden-hose water pressure.
Welcome to the wonderful world of the Tesla CD Turbine!
Step 8: Assemble the CD Turbine
Assemble your preferred CD Disc Pack on the CD Spindle, twist on the Spindle Cover and attach a garden hose to the Shut-off Valve (make sure it's closed first). Gradually adjust the pressure to make the turbine discs rotate. Water will spray out of the bottom part of the CD Cover between Spindle Cover and Spindle. It gets a little messy, so be prepared.
You can avoid most of the water spray mess by carefully sealing the Spindle Cover to the Spindle with hot-glue. If you need to change the disc pack inside, it can be done by peeling back the cooled hot-glue, then later re-gluing the cover back on.
Step 9: Fun Things to Do With the Basic Tesla CD Turbine
Well now that you built it, what can you do with this basic version of the Tesla CD Turbine?
1.) Put on your favourite old (scratched?) CD on top for the world to see. Call it the Worlds First Turbine-Powered CD Player!
2.) Paint on a Hypno-Disc and watch it intently for a few hours...
3.) Attach a water pressure gage and find out how water pressure affects speed of the discs. Get a digital laser Tach and make a graph of pressure vs RPM. Use the CD Turbine as a lawn sprinkler at the same time.
4.) Try altering the Nozzle to get better speed. Is it better with smaller or larger diameter nozzle? Flat or round outlet? What angle? E-mail me when you find out!
5.) OK, maybe you find all of the above too boring.
Well then, think of the awesome possibilities when I tell you how to get power out of this same CD Turbine, with a Magnetic Disc Pack and Magnetic Coupler.
Check out new videos in the new SinkScience series showing the CD Turbine in action, running at the kitchen sinkl on water faucet pressure...First movie below, check for latest at my YouTube/MrfixitRick
Also, check out pics of the awesome new model below; the Steampunk Parlour Room Tabletop version of the CD Turbine.
Also, see a wild CD Turbine-powered Skilsaw in my next Instructable!
Step 10: How Fast Can It Go? ...and a Safety Reminder.
Everyone wants to know how fast it will go...that's natural in our fast-moving world. But keep something in mind...to set speed records with this tiny, but powerful, device requires a special test zone, preferably not in a populated area!
CD's will explode when over-revved. This includes any RPM over 20,000 rpm. It is unlikely that more than a couple thousand rpm will be achieved by ordinary water pressure. (1400 rpm was max with my last test on water pressure).
But, again, I must stress that this innocent-looking machine becomes a screaming demon when powered by high air pressure. The CD Turbine, with 120 psi straight air pressure, will easily exceed 20,000 rpm and will violently explode the CD's in the Disc Pack. Not maybe...it will for sure. Don't use air pressure unless you are completely aware of this!
I use an air pressure regulator, digital tachometer, and a bullet-proof enclosure for high-rpm air pressure testing. And all the usual self-protection gear for dealing with sharp shrapnel.
So, be careful, wear protection and have fun!
Oh, by the way, the CD Turbine, with the plain Disc Pack has gone 14,500 rpm on half-throttle compressed air, smooth and safe!, and 11,000 rpm for the Magnetic Disc Pack. So far, so good!
I'll show more secrets in the next Instructable of the amazing Tesla CD Turbine.
UPDATE: see my latest instructable for lots more CD turbine fun, with the new Kitchen Sink Model.
Step 11: Cool CD Turbine Movies
The first video is an overview of the basic faucet-powered CD Turbine and levitating Magnetic Coupler.
The second movie is of some unusual movement of a rotating ball magnet influenced by the turbine.
The third movie is the creation of a beautiful vortex by the magnetic coupler. Enjoy!