3D-Printed Turbine Rotary Tool Tops 40,000 RPM

For your high speed, low torque needs, few things beat a rotary tool like a Dremel. The electric motor has its limits, though, they generally peak out at 35,000 rpm or so. Plus there’s the dust and the chips to deal with from whatever you’re Dremeling, so why not kill two birds with one stone and build a turbine-driven rotary tool attachment for your shop vac?

Another serious shortcoming of the electric Dremels that is addressed by [johnnyq90]’s 3D-printed turbine is the lack of that dentist’s office whine. His tool provides enough of that sound to trigger an attack of odontophobia as it tops out at 43,000 rpm. The turbine’s stator and rotors are 3D-printed, as is the body, inlet scoop, and adapter for the vacuum line. A shaft from an old rotary tool is reused, but a new one could be turned pretty easily. The video below shows the finished tool in action; there’ll no doubt be objections in the comments to ingesting dust, chips, and incandescent bits of metal, but our feeling is that the turbine will hold up to these challenges pretty well. Until it doesn’t, that is.

We like [johnnyq90]’s design style, which you may recall from his micro Tesla turbine or nitro-powered rotary tool. He sure likes things that spin fast.

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Home Built PCB Mill Reportedly Doesn’t Suck

It’s 2017, and getting a PCB professionally made is cheaper and easier than ever. However, unless you’re lucky enough to be in Shenzhen, you might find it difficult to get them quickly, due to the vagaries of international shipping. Whether you want to iterate quickly on designs, or just have the convenience of speed, it can be useful to be able to make your own PCBs at home. [Timo Birnschein] had just such a desire and set about building a PCB mill that doesn’t suck.

It might sound obvious, but it bears thinking about — if you know you’re incapable of building a good PCB mill in a reasonable period of time, you might save yourself a lot of pain and lost weekends by just ordering PCBs elsewhere. [Timo] was fairly confident however that the build would be able to churn out some usable boards, however, and got to work.

The build is meant to be accessible to the average hacker who wants one. The laser cut & 3D printed parts are readily available these days thanks to online services that can manufacture for those who don’t have the machines at home. [Timo] uses a rotary multitool for a spindle, a common choice for a budget CNC build.

With the hardware complete, [Timo] has spent time working on optimising the software side of things. Through careful optimisation of the G-Code, [Timo] has been able to improve performance and reduce stress on the tooling. It’s not enough to just build a good mill — you’ve got to have your G-Code squared away as well.

Overall, the results speak for themselves. The boards don’t suck; the mill can do traces down to 8 mil, and even drill the holes. We’d love to have one on the workbench when busting out some quick prototypes. For another take on the home-built PCB mill, why not check out this snap-together version?

Nitro Powered Rotary Tool

We really don’t know if the world needs it but we’re sure glad [johnnyq90] took the time to build one. We’re talking about a nitro powered rotary tool. Based on a Kyosho GX-12 nitro engine, commonly used in R/C cars, [johnnyq90] machines almost all other parts in his shop to make a really cool ‘Nitro-Dremel’. But success didn’t come at the first try.

The first prototype was made using a COX 049 engine but the lack of proper lubrication cause damage to the crankshaft. Because of this setback, [johnnyq90] swaps it out with a O.S Max 10 Aero engine he had lying around in the shop. That didn’t work out so well as the engine was quite hard to start. On the third try he finally decided to use the 2.1 cc Kyosho GX-12 engine to power up his 20.000 rpm tool. As noisy as one would expect and, from the videos it seems quite powerful too as it easily pierces through an aluminium block, cuts steel like a breeze, and breezes through other less demanding feats.

But [johnnyq90] is no stranger to nitro engines nor to Hackaday. In the past he built, among other things, a nitro powered cordless drill and showed impressive feats of machining in a micro version of a Tesla turbine. We wonder what’s next…. a nitro powered tattoo gun perhaps?

In the 20 minute video after the break, we enjoy watching the construction of the ‘Nitro-Dremel’, as well as other parts from two previously failed prototypes:

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The Mother Of All Paper Cuts

A Dremel is a fantastically handy tool to have around the workbench, but there is one glaring and obvious downside: you will always run out of cut-off discs. if you’re trying to break into a fancy snap-fit enclosure that has been inexplicably glued together, you’ll invariably need to run down to the hardware store to shell out some cash for a tiny tube of cut-off disks.

[KB9RLW] has the answer to this problem. He’s cutting wood and plastic with paper discs spinning at 35,000 RPM.

The paper used for this application is just a piece of junk mail or heavy, probably glossy card stock. After poking a hole in this piece of paper, tracing a circle with a homemade compass, and cutting out the cutting disk with a pair of scissors, this cut-off disc is easily mounted in the standard Dremel mandrel.

The test cut [KB9RLW] shows us is on a plastic wall wart that’s a glued together, snap-fit mess. The paper cut-off wheel makes short work of this nigh-impenetrable brick of plastic, revealing the electronic goodies inside. This cut-off wheel will also cut through small bits of wood, like a bit of molding.

After cutting halfway through the wooden molding, the paper disc quickly disintegrates — this is the same behavior we last year when this trick was being used on a table saw. But any home should get more than enough junk mail for a steady supply of paper Dremel cut-off discs. While this new attachment for your fancy rotary tool won’t last very long, it is a very expedient way to get into bits of electronics without paying Dremel several cents for a cut-off disc.

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3D Printer Transforms to CNC

Superficially, it is easy to think about converting a 3D printer into a CNC machine. After all, they both do essentially the same thing. They move a tool around in three dimensions. Reducing this to practice, however, is a problem. A CNC tool probably weighs more than a typical hotend. In addition, cutting into solid material generates a lot of torque.

[Thomas Sanladerer] knew all this, but wanted to try a conversion anyway. He had a few printers to pick from, and he chose a very sturdy MendelMax 3. He wasn’t sure he’d wind up with a practical machine, but he wanted to do it for the educational value, at least. The result, as you can see in the video below, exceeded his expectations.

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DIY Rotary Tool

[Shashank] has a modest tool collection but is missing a rotary tool. He needed one for a project he was working on but didn’t think that it would get much use after the current project was completed. So instead of buying a rotary tool, he decided to make one to get the job done.

The project started out with a 40mm PVC pipe that would serve a the main body of the tool. Two MDF disks were cut to fit inside the pipe. One was used for mounting an RC vehicle brushless motor and the other was bored out to accept a pair of bearings. The bearings supported a modified pin vise that acts as the chuck for securing rotary tool bits. A 20-amp ESC and a servo tester control the motor’s speed and can get the motor up to 18,000 rpm.

Although this worked for a while, [Shashank] admits it did fall apart after about 20 hours of use. The MDF bearing mounts crumbled, thought to be a result of vibration due to mis-assignment between the motor and pin vise. He suggests using aluminum for the bearing mounts and a flexible coupling to connect the motor to the pin vise. If you’re interested in making your own rotary tool but don’t have any spare motors kicking around,  this 3D printed vacuum-powered rotary tool may be for you.

DIY Super Accessory For Your Dremel

Little jobs require little tools and you can’t get much more littler than a Dremel. For his tiny tasks, [sdudley] has built a Dremel-powered base station that features a table saw, drum sander and router table. Overall, it is about one cubic foot in size and is almost entirely made from ‘1 by’ dimensional lumber. The Dremel power plant was actually used to make the base, specifically slowly removing material at the clamping points that hold the rotary tool secure to the base. The Dremel is held in an upright position and pokes out through the center of the table for both the drum sander and router configurations. To use this as a table saw, the Dremel is mounted almost horizontally on the base. A Mini Saw attachment has to be purchased for the table saw configuration but it does a great job at holding a vertically spinning saw blade.

After the break there’s a nice video of this tool’s use and assembly (it’s even worth watching just for the musical accompaniment that takes you on a wild ride through several genres of music). For those who want to make one for themselves, [sdudley] has made his part templates and assembly guide available in PDF format on his Instructables page. If you’re looking for something a little larger, check out this circular saw converted to a table saw.

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