[Integza] built a Tesla turbine and wanted to know how fast it was spinning. However, he didn’t have a tachometer, and didn’t want to buy one. After a false start of trying to analyze the audio to measure the speed, he decided to use a tried-and-true method. Let the wheel break an infrared (IR) optointerruptor and count the spokes of the wheel as they go by. If you know the spacing between the spokes, you can compute the speed. There was only one problem: it didn’t work.
Turns out, PLA is at least somewhat transparent to IR. Knowing that it was a simple matter to fix some tape to the wheel that would block IR and that made things work much better. If you missed the video where he built the turbine, you might want to watch it first.
Continue reading “PLA Foils Homemade Tachometer”
A corollary to Godwin’s Law ought to be that any Hackaday post that mentions Nikola Tesla will have a long and colorful comment thread. We hope this one does too, but with any luck it’ll concentrate on the engineering behind this tiny custom-built Telsa turbine.
For those not familiar with Mr. Tesla’s favorite invention, the turbine is a super-efficient design that has no blades, relying instead on smooth, closely spaced discs that get dragged along by the friction of a moving fluid. [johnnyq90]’s micro version of the turbine is a very accomplished feat of machining. Although at first the build appears a bit janky, as it progresses we see some real craftsmanship – if you ever doubt that soda can aluminum can be turned, watch the video below. The precision 25mm rotor goes into a CNC machined aluminum housing; the way the turned cover snaps onto the housing is oddly satisfying. It looks like the only off-the-shelf parts are the rotor bearings; everything else is scratch-made. The second video ends with a test spool-up that sounds pretty good. We can’t wait for part 3 to find out how fast this turbine can turn.
Size matters, and in this case, small is pretty darn impressive. For a larger treatment of a Tesla turbine, see this one made of old hard drive platters.
Continue reading “Micro Tesla Turbine is an Engineering Tour de Force”
You probably weren’t expecting a project based on [Nikola Tesla’s] work to show up during the Engine Hacks theme. Most people know of him because of his pioneering work with high voltage equipment. Never the less, [Tesla] designed a device that later became known as the Tesla Turbine. Tesla turbines are made out of a series of thin disks attached to a central rotor. Air or steam is injected into the closed turbine housing at the outer edge of the disks. It swirls around through the turbine blades and eventually exits near the rotor. This type of turbine can achieve very high rotational speeds but doesn’t have a lot of torque, which limits their usefulness. Check out this instructable that shows you how to build your own Tesla turbine out of hard drive platters.
We have featured a Tesla turbine in the past on Hackaday. In this previous post, [Rick] shows us how to carve a pumpkin with a skill saw blade that is powered by one of these turbines.
[Ani Niow] built this steam powered vibrator. It has a milled stainless steel shell with a brass motor structure. The motor is a Tesla turbine made from a stack of Dremel diamond cutoff wheels. This drives an off-center weight to create the vibration. She tested it using a pressure cooker as the steam source. It worked, but became so hot it had to be held using welding gloves. It works just as well with compressed air though. You can see the device at the Femina Potens Art Gallery in San Francisco or later this month at Maker Faire.
[via Laughing Squid]
UPDATE: [Ani] responds in the comments.
[Rick] has been building Tesla turbines in various ways and posting his projects to youtube. For those who are unfamiliar, a tesla turbine is a fanless turbine that uses a smooth central disk spun by friction from a gas or fluid. Since the turbine itself has no protrusions, it is extremely stable. There are lots of other benefits, which can be explored on the Wikipedia page. [Rick], as you can see from the video above has found several uses for them, from Halloween props, to generators for lights, to an automated shake flashlight shaker, you can even watch him rev one up to destruction. Though most of these are at relatively low speeds, he has shown that he can make one from CD spindles that is stable enough to reach 10,000 RPM. [Rick] admits that all they really do is spin fast and make cool noises, but they do that pretty well.
Update: Moments after this was published, we found an instructable by [Rick] on how to build a blender using a tesla turbine.