Turning A Rotary Tool Into A CNC

November 16, 2018 by Brian Benchoff 32 Comments

Now that 3D printers are everywhere, electronics are cheap, and open source software is extremely capable, just about anyone can build a CNC machine. That’s exactly what [Nikodem] did by turning a Dremel tool into an extremely capable CNC machine that’s able to cut MDF and acrylic and can engrave aluminum.

The electronics for the build are just an Arduino Uno, a motor driver sheld running GRBL, a relay for the Dremel, a few motor drivers, and a big ‘ol 30 A power supply. The build uses NEMA 17 motors, two on the Y-axis and one each on the X and Z. The CNC has a fantastically strong frame despite the 3D printed parts. It is constructed out of aluminum extrusion, with the carriages riding on some nice straight rods.

As for how well this CNC machine works, it’s pretty good. With the Gcode to cut an 80mm diameter circle out of MDF, this machine managed to cut a circle that was 80.02 mm in diameter. That’s pretty good, and getting into the territory that the error is probably in the cheap set of calipers, not the finished part itself. It’s an awesome build, and [Nikodem] has everything documented in his four-part video series. You can check the end of that out below.

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Scratch Built Toe Clamps Keep Your Work In Place

November 5, 2018 by Donald Papp 15 Comments

[Kevin] owns a benchtop CNC mill that has proven itself to be a capable tool, but after becoming familiar with some of its shortcomings, he has made a few modifications. In order to more efficiently hold and access workpieces on his custom fixturing table, he designed and made his own toe clamps and they look beautiful.

The usual way to secure a piece of stock to a fixturing table is to use top-down clamps, which hold the workpiece from the top and screw down into the table. However, this method limits how much of the stock can be accessed by the cutting tool, because the clamps are in the way. The most common way around this is to mount a vise to the table and clamp the workpiece in that. This leaves the top surface completely accessible. Unfortunately, [Kevin]’s benchtop Roland MDX-450 has a limited work area and he simply couldn’t spare the room. His solution was toe clamps, which screw down to the table and have little tabs that move inwards and downward. The tabs do the work of clamping and securing a piece of stock while maintaining a very low profile themselves.

The clamp bases are machined from stainless steel and the heads are brass, and the interface between the two is a set screw. Inserting a hex wrench and turning the screw moves the head forward or back, allowing a workpiece to be clamped from the sides with minimal interference. His design was done in Fusion 360 and is shared online.

Another option for when simple clamps won’t do the job is a trick from [NYC CNC], which is to use an unexpected harmony of blue painter’s tape and superglue which yields great results in the right circumstances.

Use Nodes To Code Loads Of G-code For 3D CNC Carving

October 17, 2018 by Brian Boucheron 9 Comments

Most CNC workflows start with a 3D model, which is then passed to CAM software to be converted into the G-code language that CNC machines love and understand. G-code, however, is simple enough that rudimentary coding skills are all you need to start writing your very own programmatic CNC tool paths. Any language that can output plain text is fully capable of enabling you to directly control powerful motors and rapidly spinning blades.

[siemenc] shows us how to use Grasshopper – a visual node-based programming system for Rhino 3D – to output G-code that makes some interesting patterns and shapes in wood when fed to a ShopBot. Though the Rhino software is a bit expensive and thus is not too widely available, [siemenc] walks through some background, theory, and procedures that could be useful and inspirational no matter what software or programming language you’re using to create your bespoke G-code.

For links to code and related blog posts, plus more lovely pictures of intricately carved plywood, check out [siemenc]’s personal site as well.

[via Bantam Tools]

DIY Wire Bender Gets Wires All Bent Into Shape

October 14, 2018 by Steven Dufresne 31 Comments

It’s been a while since we’ve shown a DIY wire bending machine, and [How To Mechatronics] has come up with an elegant design with easy construction through the use of 3D-printed parts which handle most of the inherent complexity. This one also has a Z-axis so that you can produce 3D wire shapes. And as with all wire bending machines, it’s fun to watch it in action, which you can do in the video below along with seeing the step-by-step construction.

One nice feature is that he’s included a limit switch for automatically positioning the Z-axis when you first turn it on. It also uses a single 12 volt supply for all the motors, and the Arduino that acts as the brains. The 5 volts for the one servo motor is converted from 12 using an LM7805 voltage regulator. He’s also done a nice job packaging the Arduino, stepper motor driver boards, and the discrete components all onto a single custom surface mount PCB.

The bender isn’t without some issues though, such as that there’s no automatic method for giving it bending instructions. You can write code for the steps into an Arduino sketch, which is really just a lot of copy and paste, and he’s also provided a manual mode. In manual mode, you give it simple commands from a serial terminal. However, it would be only one step more to get those same commands from a file, or perhaps even convert from G-code or some other format.

Another issue is that the wire straightener puts too much tension on the wire, preventing the feeder from being able to pull the wire along. One solution is to feed it pre-straightened wire, not too much to ask for since it’s really the bending we’re after. But fixing this problem outright could be as simple as changing two parts. For the feeder, the wire is pulled between copper pipe and a flat steel bearing, and we can’t help wondering whether perhaps replacing them with a knurled cylinder and a grooved one would work as the people at [PENSA] did with their DIWire which we wrote about back in 2012. Sadly, the blog entries we linked to no longer work but a search shows that their instructable is still up if you want to check out their feeder parts.

As for the applications, we can think of sculpting, fractal antennas, tracks for marble machines, and really anything which could use a wireframe for its structure. Ideas anyone?

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Tiny Plotter Is Made Of Strings And Cardboard

October 4, 2018 by Tom Nardi 14 Comments

If you’ve been hanging around Hackaday for any length of time, you’ve undoubtedly seen the work of [Niklas Roy]. A prolific maker of…everything, we’ve covered his projects for over a decade now. He’s one of an elite group of hackers who can say they’ve been around since Hackaday was still using black & white pictures. Yet sometimes projects fall through the cracks.

Thanks to a tip sent in from one of our beloved readers, we’re just now seeing this incredible cardboard plotter [Niklas] made for a workshop he ran at the University of Art and Design Offenbach several years ago. The fully manual machine is controlled with two rotary dials and a switch, and it even comes with a book that allows you to “program” it by dialing in specific sequences of numbers.

Not that it detracts from the project, but its worth mentioning that the “cardboard” [Niklas] used is what is known as Finnboard, a thin construction material made of wood pulp that looks similar to balsa sheets. The material is easy to work with and much stronger than what we’d traditionally think of as cardboard. Beyond the Finnboard, the plotter uses welding rods as axles and slide rails, with glue, tape, and string holding it all together.

The dials on the control panel correspond to the X and Y axes: turning the X axis dial moves the bed forward and backward, and the Y dial moves the pen left and right. The switch above the dial lowers and raises the pen so it comes into contact with the paper below. With coordination between these three inputs, the operator can either draw “freehand” or follow the sequences listed in the “Code Book” to recreate stored drawings and messages.

Believe it or not, this isn’t the first time we’ve seen somebody made a plotter out of cardboard. Though previous entries into this specific niche did use servos to move around.

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Faux Aircon Units, Made Entirely From 2D Cuts

September 28, 2018 by Donald Papp 9 Comments

2D design and part fabrication doesn’t limit one to a 2D finished product, and that’s well-demonstrated in these Faux Aircon Units [Martin Raynsford] created to help flesh out the cyberpunk-themed Null Sector at the recent 2018 Electromagnetic Field hacker camp in the UK. Null Sector is composed primarily of shipping containers and creative lighting and props, and these fake air conditioner units helped add to the utilitarian ambiance while also having the pleasant side effect of covering up the occasional shipping container logo. Adding to the effect was that the fan blades can spin freely in stray air currents; that plus a convincing rust effect made them a success.

Fan hubs, showing spots for fan blades to be glued. With the exception of embedded bearings, the entire hub (like the rest of the unit) is made from laser-cut MDF.

The units are made almost entirely from laser-cut MDF. The fan blades are cut from the waste pieces left over from the tri-pronged holes, and really showing off the “making 3D assemblies out of 2D materials” aspect are the fan hubs which are (with the exception of bearings) made from laser-cut pieces; a close-up of the hubs is shown here.

Capping off the project is some paint and the rusted appearance. How did [Martin] get such a convincing rust effect? By using real rust, as it turns out. Some cyanoacrylate glue force-cured with misted water for texture, followed by iron powder, then vinegar and hydrogen peroxide with a dash of salt provided the convincing effect. He was kind enough to document the fake rust process on his blog, complete with photos of each stage.

Null Sector showcased a range of creativity; it’s where this unusual headdress was spotted, a device that also showed off the benefits of careful assembly and design.

A Rotary Axis CNC Machine

September 24, 2018 by Brian Benchoff 20 Comments

There’s a certain class of parts that just can’t be made on a standard 3-axis mill, nor with a 3D printer or a lathe. These parts — weird screws, camshafts, strange gears, or simply a shaft with a keyway (or two) — can really only be made with a rotary axis on a CNC machine. Sure, you could buy a rotary axis for a Haas or Tormach for thousands of dollars, or you could build your own. That’s exactly what [Adam Zeloof] and [Matt Martone] did with their project at this year’s World Maker Faire in New York. It’s the Rotomill, a simple three-axis CNC machine, with a rotary axis, that just about anyone can build.

The design of the Rotomill uses a standard, off-the-shelf Makita rotary tool for the spindle, and uses leadscrews to move the X and Z axes around with NEMA 24 stepper motors. The A axis — the rotary bit — is driven through a worm gear, also powered by a NEMA 24. Right now this provides more than enough power to cut foam, plastic, and wood, and should be enough to cut aluminum. That last feat is as yet untested, but the design is open enough that a much more powerful spindle could be attached.

The software for this machine is a bit weird. For most CNC machines with a rotary axis, the A axis is treated as such — a rotary axis. For the Rotomill, [Adam] and [Matt] are generating G Code like it’s a normal Cartesian machine, only with one axis ‘wrapped’ around itself. This is all done through Autodesk HSM, and a properly configured Arduino running GRBL makes sense of all this arcane geometry.

It’s a great looking machine, and the guys behind it say it’s significantly less expensive than any other machine with a rotary axis. That’s to be expected, as it’s basically a five axis mill with two axes removed. Still, this entire project was built for about $2000, and some enterprising salvage and hacking could bring that price down a bit.