The Chicken and Broccoli PT-3 was an inspiration to a "kitchen table engineer" like myself. Thanks for presenting things like that along side the more "advanced" efforts which also are no less inspiring, but a little beyond my abilities and resources at the moment. Maybe I will get it together enough to submit my own kitchen-table turbine and eventually work up to something more substantial.

Anyway... I just wanted to let you know that your site is doing what you might have intended it to do.. inform and inspire other people to explore other energy possibilities and in doing so, slowly change the course we're on at the moment.

"For good adhesion, it is important that the adhesive can readily flow out on the surface. The degree, or freeness, of the flow often determines the intensity of adhesion. Degree of flow depends on the difference between the surface energy of the material and the surface energy of the adhesive. Pressure-sensitive adhesives tend to flow out on materials having a high surface energy -- for instance, metals, glass and plastics such as acrylic, polycarbonate and nylon. Pressure-sensitive adhesives tend not to flow out as easily on low surface-energy materials such as polyethylene, polypropylene and Teflon."

Project 1. My goal is to drive linear pneumatic actuators with steam. For aesthetic, but mainly efficiency reasons, it was my hope to avoid the rotational stage altogether. But pushing steam down longish feed pipes will result in quick condensation and loss of power. So I thought to use the steam to compress air as a way of storing and transferring power. This led me to imagine a small efficient in-out turbine, with steam in and compressed air out. Research on microturbines led me to your site. I imagine that one could build a pair of in-line tesla turbines (or a double

turbine unit) to do this job very efficiently. Do you know of any examples of turbines (built or in process) doing this sort of thing?

Project2. This idea is somewhat less developed. Use two small turbines with gear heads to independently power two wheels of a wheelchair-sized vehicle. This is mechanically more complex, I guess. Given the momentum of the turbine, one would have to include, at least, a conventional clutch and reversing gear, after the reduction stage. This would suggest a more

conventional automobile drive train with differential, which in turn leads me to ask which of the small automobile/go kart projects is/are showing promising results. My interest here is economy/efficiency, not performance.

I did start a few years ago on a case and discs. I stupidly only stamped the centers and not the diameters. I now have 200+ plates that have to be machined still. I never could find the information for disc number and spacing for the compressor and turbine. I had planned on using x3 for the compressor x1 for the turbine and x2 for the exhauster. Around 24 discs for the turbine 10" dia. I thought of using 3 burner cans so I could vary the output/economy. I built from cheap steel sheet but did price Inconel, $1,000 would be enough for the turbine. With water cooling would it be worth it?

If you lived in South America you know this terrible loop of poverty-destruction. We are proposing a permanent culture, or permaculture. This is a practice that works to enrich the biomass, conserving at the same time the wild life. In this practice we need to eliminate or reduce at minimum all external energetic input. Now appears the importance of free energy.

We admire your service and we hope that this the light in the bottom of the hole. We are waiting your positive answer: it is possible to build an effective, rapid, low low-cost Tesla turbine? (Because Tesla turbines are not our target, we focus on sustainability.) Best wishes -- Leo

On the subject of cases, I have laying around two Briggs and Straton 3 HP lawn mower motors (horizontal crank), and one disembodied Toro 2-cycle weed eater motor that refuses to start.

One, Has anyone considered the use of an arc as apposed to the straight edges on the star washer? The turbo shaft uses a boundary layer effect to drag the disk pack and shaft along with the flow of the "fluid". So the use of an arc shaped star washer would seem to work to in your favor because one, the edge the "fluid" strikes would have a slight increase in surface area. Two, the leading edge would cause a less turbulent flow.

Questions:

1. What is the intended use of this Turbine Engine?
2. What is the estimated budget of the build?
3. I live in Houston, TX and snowmobile engines are hard to come by. Is there a suitable engine housing from a lawn mower or a 4-wheeler?
4. I have very little access to machine shop equipment, would any of your members be interested in making some of the parts for me?

Use Tesla’s original work to determine your requirements. He used around 32 disks at 10" diameter for 110 hp at 18,000 rpm using steam as a working fluid. Since horsepower changes in direct proportion to the surface area, half the number of disks will yield half the horsepower.

Another consequence of this is that it could allow for a lower operating speed and perhaps remove the need for a torque converter.

A: The Tesla turbines we are building are turbo-shaft rather than jet engines. The project described in our Turbine Builders Club is designed for around 20-30 hp. Higher horsepower requires larger shafting, additional disk surface area, etc. Since you are starting work in a metal shop, they may have the lathes & mills necessary to turn the parts.

Also, since the project will take a while to build, your best strategy is to stick to conventional piston engine transportation while experimenting with turbines at lower horsepower ratings – then build your larger engines after gaining enough know-how.

Q: Hello, I have been watching this site for a few months now I am very interested in building a turbine generator. I may be jumping the gun here as it might be discussed in a later article, but in your last article you did not specify what type of material you are using for the shaft. I have a shaft from an old conveyer, but after giving it some thought. I have decided to have a local hydraulic shop turn down a shaft from the same stock they use in building hydraulic cylinders...

I am going to use a laser to cut the disks and again want to know what type of material you are going to use, also are you going to post .DXF or .DWG files at this site? I can have a .DXF file converted to G_code that the laser will recognize. Thanks in advance. -- Don (California)

A: Since we are dealing with relatively light loads, the shaft material isn’t extremely important provided you don’t go under the minimal 1.125" (for 30 mm bearings). Any carbon steel similar to 4140 will do. If you are using stainless, you will want a good 316 or 416 type for the shaft.

For the disks you want a material that will withstand at least 50,000 psi tensile strength. Again, 4140 carbon steel or 316/416 stainless will work - depending on how much heat and the type of gas you feed to it. Normally you use 316 stainless for disks.

At this time we don’t have plans to post CAD files – mainly because the technology is so flexible we would have too many versions of the basic design. Also since just about any case can be used with our approach, we couldn’t possibly cover all of the variables. When we get to specific parts such as disks, flanges, etc. you can contact me by email for DXF files.

A: At this time we don’t have plans for covering the 100 hp design on the Turbine Builders Club, although it may be a good follow on to the 2-cycle units we are now working with.

Since the retrofitting of turbines to piston-driven vehicles is so new and basically unproven, we don’t have much response yet in that program. We will however put your name on a list and try to match you to a shop in your area once the program catches on.

The real value of these simple first experiments is to take a look at aerodynamics principles of boundary layer, drag effects of the round washer spacers, and the lift/drag characteristics of wing sections – to see if there is a pathway to an improved combination of geometric shapes that work together more efficiently. There are thousands of combinations of shapes, angles of attack, spacings, etc. that may be tuned to specific gas pressures and disk rpm for best efficiency points.

What we are simply stating in these preliminary experiments is that winglet geometry tends to spin the disk pack from zero rpm to a figure 30% higher than an identical disk pack with round washers. In the next PTBC discussion we’ll go into some of the theoretical concepts that led us in this direction. Another factor that pointed us toward winglets was a test report from associates of ours describing boundary-layer water pumps.

Your points are well taken, and we plan to conduct additional tests at sustained air pressures and higher speeds as time & resources permit. Since all turbines increase efficiency with speed, it should be interesting to compare the two designs once they move upwards from the stall point (around 50% of rated speed).

Q: ...I am new to the Tesla turbine technology. Now that I found it I really want to embrace it quickly. I have a cogeneration project based around wood gasifier, on a small Goat dairy operation in central Wisconsin. I plan to be operational at least on an experimental basis by August. I think this turbine workshop might offer me just the opportunity to dabble with microturbines without the $20k price tag.

Can you direct me anywhere to get up to speed better? What kind of RPMs are we dealing with... And for the biggy, how tolerant of tars would this turbine be if powered by Wood gas? -- Scott (Wisconsin)

A: The best way to gain a basic understanding of Tesla turbine technology is to join an organization like TEBA (Tesla Engine Builders Association), and immediately back-order their newsletters #15-18. They also have an excellent membership manual and an optional book entitled "Tesla’s Engine". Keep checking back to our Phoenix Turbine Builders Club for monthly updates on how to go about assembling a turbine from junk engine blocks, off-the-shelf bearings, and easy to machine parts.

RPMs depend on the hot rotor diameter – about 18,000 rpms for a 10-inch rotor, and 10,000 rpms for an 18-inch rotor. Wood tar much be scrubbed from the gas before it can be used in any internal combustion engine, including Tesla turbines. An alternative is to use the wood gas to generate steam, then use the steam in a closed loop to drive the turbine.