Build an Amazing Tesla CD Turbine

Step 11 Cool CD Turbine Movies

Here's a few of my latest SinkScience videos. I've been having lots of fun, and learning, with the faucet-powered Tesla CD Turbine.

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!

Comments

[Zem]

Is it just me, or in the second picture is there an Alternator connected to it?

[mrfixitrick]

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.

[Rottom]

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]

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.

[Rottom]

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]

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.

[Rottom]

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]

Be careful...The Tesla Turbine is a deceptively simple device that will give a lifetime of experimenting and learning to those who get addicted!

[seamaas]

how would you set that up?

[mrfixitrick]

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!!

[FurtherThanTesla]

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]

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.

[FurtherThanTesla]

and also, would a modified gasoline engine (like a small mower engine) be able to handel those kind of forces?

[FurtherThanTesla]

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.

[lperkins]

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.

[FurtherThanTesla]

i just love messing with auto alternators :3

[Zem]

=D.

Excellent I was wondering if that was possible.

Ah, well I hope you find a more successful setup!

[tomcasull]

I was wondering, if you run it through a gearing device could you reduce the the friction loss and increase the RPM of the alternator?

[mrfixitrick]

I believe that will only work with more water pressure to the turbine.

[matthew gowan]

In theory this could be made into a desk model by capping the top housing and driving the magnetic coupler through a small d.c. motor.