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”
When a large bandsaw broke down due to a cast iron part snapping in two, [Amr] took the opportunity to record the entire process of designing and creating a solid steel replacement for the broken part using a (non-CNC) mill and lathe.
For those of us unfamiliar with the process a machinist would go through to accomplish such a thing, the video is extremely educational; it can be sobering both to see how much design work happens before anything gets powered up, and just how much time and work goes into cutting and shaping some steel into what at first glance looks like a relatively uncomplicated part.
Continue reading “Fixing a Broken Bandsaw with a Custom Steel Part”
[This Old Tony] teaches us how to make springs on a lathein this video done in the style of How It’s Made. Mixed in with snark, in his usual style, is a lot of useful information.
The Machinery’s Handbook certainly has all the information one would need to design the basic spring shapes, but it’s not always necessary. [Tony] points out that cheating is entirely acceptable. For example, if you need a spring that’s close to the dimensions of a standard spring, simply copy over the values from the standard spring. He explains all the terminology needed to decrypt the pages in your engineering tome of choice.
He shows the basics of winding a spring on a mandrel (or that round metal thing, if you want to use the industry term). First wind the inactive coils, then set your lathe to the desired spring pitch. Engage it as if threading, then disengage and wind the final inactive coils. A quick trip to the sander squares the ends of a standard coil spring. However, the tools can also be used to make torsion springs, or even exotic combination springs.
For a good… educational laugh, watch the whole video after the break.
Continue reading “Making Springs At Home”
At first glance, [Frank Howarth]’s turned bamboo Death Star seems like a straight woodworking project. No Arduino controlled lights, no Raspberry Pi for audio clips of an X-wing attack or escaping TIE fighter. In other words: where’s the hack?
It’s a freaking bamboo Death Star!
If that’s not enough for you, check out the pattern on the surface of the finished model. That’s not painted on – those are the layers of the laminated bamboo lumber used to create the rings [Frank] used to form the structure. After lots of turning, sanding and polishing, the characteristic vascular bundles of the bamboo create light and dark panels for a convincing effect of the Death Star’s surface detail. And although we like the natural finish, we can imagine a darker stain might have really made the details pop and made for an effect closer to the original.
Still not hackish enough? Then feast your eyes on [Frank]’s shop. It’s a cavernous space with high ceilings, tons of natural light, and seemingly every woodworking machine known to man. While the lathe and tablesaw do a lot of the work for this build, the drool-worthy CNC router sees important duty in the creation of the multiple jigs needed for the build, and for making the cutout for the superlaser, in what must have been a tense moment.
Bamboo is an incredible material, whether for fun builds like this or for more structural uses, like a bamboo bike. All this bamboo goodness puts us in the mood to call on [Gerrit Coetzee] for a new installment on his “Materials You Should Know” series.
Continue reading “That’s No Moon – That’s a Bamboo Death Star”
Mini Sumo seems like one of those hobbies that starts out innocently enough, and ends up with a special room in the house dedicated to it. One day you’re excitedly opening up your first Basic Stamp kit, and the next you’re milling out mini molds on a mini lathe to make mini extra sticky tires.
[Dave] started out trying to find a part from the local big box store that was just a little bigger than the wheel he wanted to rubberize. He set the wheel inside a plumbing cap and poured the urethane in. It worked, but it required a lot of time with a sharp knife to carve away the excess rubber.
In the meantime he acquired a Sherline Mini Mill and Lathe. With the new tools available to him, he made a new mold out of a bit of purple UHMW and some acrylic. This one produced much nicer results. Using a syringe he squeezed resin into the mold through a hole in the acrylic. Much less cleanup was needed.
He later applied these methods to smaller, wider wheels as his mini sumo addiction took a stronger hold on his life.
Look up ‘concrete lathe’ and you’ll quickly find yourself reading the works of [David Gingery]. His series of books on building a machine shop from scrap begin with a charcoal foundry, and quickly move to creating a metal lathe out of concrete. Before [Gingery]’s lathe, around the time of World War I, many factories created gigantic machine tools out of concrete. It’s an old idea, but you’ll be hard pressed to find anyone with a shop featuring concrete machine tools. Cheap lathes are plentiful on Craigslist, after all.
Building a metal lathe from concrete is more of a challenge. This challenge was recently taken up by [Curt Filipowski] in a five part YouTube series that resulted in a real, working lathe made out of concrete, scrap, and a lot of bolts.
The concrete lathe begins with a form, and for this [Curt] cut out all the parts on a CNC router. Creating the form isn’t quite as simple as you would think – the concrete form included several bolts that would alow [Curt] to bolt bearings, ways made out of gas pipe, and angle iron. This form was filled with concrete in [Curt]’s kitchen, and after a nice long cure, the lathe was moved up to the upstairs shop. That’s a five hundred pound block moved up a flight of stairs by a single person.
The rest of the build deals with the cast concrete carriage which rides along the polished gas pipe ways, a tool post holder milled out of a block of aluminum, and finally making some chips. While it’s not the most practical lathe – the carriage moves along the ways by turning a wheel underneath the tailstock – it does demonstrate a concrete lathe is possible.
Continue reading “Casting A Lathe Out Of Concrete”
When the RepRap project was founded in 2005, it promised something spectacular: a machine that could build copies of itself. RepRaps were supposed to be somewhere between a grey goo and a device that could lift billions of people out of poverty by giving them self-sufficiency and the tools to make their lives better.
While the RepRap project was hugely successful in creating an open source ecosystem around 3D printers, a decade of development hasn’t produced a machine that can truly build itself. Either way, it’s usually easier and cheaper to buy a 3D printer than to build your own.
[castvee8]’s entry into the 2016 Hackaday Prize does just what the RepRap project promised ten years ago. It’s all about building machines with the ability to reproduce, creating an ecosystem of machines to build household goods. The best part? You can 3D print most of the machines. It’s the RepRap project, but for mills, lathes, microscopes, and routers. It’s an entire shop produced entirely in a 3D printer.
The idea of creating a machine shop from the most basic building materials has been around for a while. At the turn of the last century, concrete lathes and mills bootstrapped industrial economies. Decades later, [David J. Gingery] created a series of books on building a machine shop starting with a charcoal foundry. The idea of building a shop using scrap and the most minimal tools is very old, but this idea hasn’t been updated to the era where anyone can buy a 3D printer for a few hundred dollars.
So far, [castvee8] has a few homemade machine tools on the workbench, including a lathe, a tiny mill easily capable of fabricating a few circuit boards, and a little drill press. They’re all machines that can be used to make other useful items, and all allow anyone to create the devices they need.