A 3D – To – 2D Converter To Make Plots From STLs.

December 13, 2020 by Jenny List 13 Comments

We’ve become used to finding models on websites such as Thingiverse and downloading them to print. After all, whose hackerspace doesn’t have a pile of novelty prints? How about printing them on paper? For the plotter enthusiast that can be particularly annoying. Never fear, [Trammell Hudson] is here with an online 3D to 2D converter just for plotters. [Trammell’s] creation makes a vector image suitable for a plotter while eliminating spurious behind-the-scenes lines.

Plotter drawings are the pen-and-paper equivalent of a vector CRT display, in which the graphics are printed as continuous strokes. Rendering a 3D model as a wireframe for a plotter requires the removal of any pen strokes that comes from the 3D space behind the surface in view. Loading various models into the web page seemed to do a pretty good job of this, though the ubiquitous Benchy 3d printer test model lived up to its billing as a torture test in taking several minutes to render.

As anyone who has followed the #PlotterTwitter social media hashtag will know, there is a considerable community of pen plotter enthusiasts who are pushing the boundaries of what their machines can do. [Trammell] has posted his plotter producing some of the work created with this tool, and we can see that it’s likely to work better with lower-poly models.

We’ve featured a lot of plotters over the years as they seem to be a popular project. If you’d like one then they can be made from the most available parts, including those scavenged from scrap DVD drives, or printers.

Rotary Plotter Draws On Bottles

November 11, 2020 by Lewin Day 10 Comments

A pen plotter is often the first experience many ambitious makers have of the world of Computer Numerical Control, or CNC. While they typically operate on flat stock, with the right build, they can be designed to draw on curved surfaces, too – as [tuenhidiy] demonstrates with this rotary bottle plotter.

The plotter uses shafts salvaged from an old printer to act as the rollers for the bottle to be drawn upon, turned by a pair of stepper motors. X and Z axes are created out of two CD drive mechanisms – a popular way to build two linear axes on the cheap. The hardware is controlled by GRBL, running on an Arduino Uno kitted out with a CNC shield to handle the necessary I/O.

The build is somewhat limited to by the short range of its X axis, which prevents the plotter from easily drawing on a full-size bottle label or can. However, this could easily be fixed with some upgrades and extra steppers if so desired. As a home build, it’s a great way to learn about the CNC techniques required to work with curved surfaces effectively. Video after the break.

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Watch A Fast Sand Plotter Plow Patterns At Speed

September 22, 2020 by Donald Papp 21 Comments

[Mark]’s sand table wisely has a glass top.

Most of us have probably seen a video of a sand drawing table at work, in which a steel ball — magnetically-coupled to a gantry under a layer of sand — lazily draws geometric patterns with utter precision and zen-like calmness. That’s all well and good, but [Mark Rehorst] thinks it can also be interesting to crank up the speed and watch the ball plow through sand just as physics intended. There’s a deeper reason [Mark] is working at this, however. Faster drawing leads to less crisp results, but by how much, exactly? To answer this, [Mark] simply ran his table (which is named The Spice Must Flow) at both fast and slow speeds and documented the results.

These two images show the difference between running the table at 100 mm/s versus 500 mm/s. The slower speed is noticeably crisper, but on the other hand the faster speed completed the pattern in about a fifth of the time. [Mark] says that as the ball aggressively accelerates to reach target speeds, more sand is thrown around over existing lines, which leads to a loss of detail.

Crisper detail, or a faster draw? Which is “better” depends on many things, but it’s pretty clear that [Mark]’s cat finds the fast version more exciting. You can see [Mark]’s table at high speed and the cat’s reaction in the video, embedded below.

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Cyberplotter Uses Multiple Tools To Great Success

September 17, 2020 by Lewin Day 14 Comments

The CNC bug is a familiar ailment in these parts. Often, patients present with persistent obsession with computer controlled machinery, most commonly after initial contact with gateway hardware such as 3D printers or basic plotters. Once diagnosed, there is no cure – simply the desire to build, and build again. [Adam Haile] knows this all too well, and built the Cyberplotter in service to the affliction.

The Cyberplotter is the culmination of [Adam]’s CNC wishlist – a two-axis build with a seriously large build area, and the capability to mount a whole bunch of different tools for different jobs. With a work area of up to 800mm x 750mm depending on what’s mounted, it can produce some seriously big output. With a Smoothieboard 5X running the show, [Adam] does all kinds of neat hacks to make the system play with different gadgets on the business end. There’s a laser for engraving, and a top-notch pen plotter featuring a high-quality linear rail for precise movement. But the fun doesn’t stop there – [Adam] goes so far as mounting a Z-axis, camera, and even a Sharpie-based airbrush which we’d never even contemplated before.

It’s not [Adam]’s first build, and past experience shines through here – armed with prior knowledge, the build does many things well without compromising on outright capability. You may find [Adam]’s name familiar – we’ve featured his Engravinator on these pages before. Video after the break.

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Art Piece Builds Up Images With Dots On Thread

August 1, 2020 by Dan Maloney 7 Comments

Hackers being as a rule practical people, we sometimes get a little guff when we run a story on an art installation, on the grounds of not being sufficiently hacky. We understand that, but sometimes the way an artist weaves technology into their pieces is just too cool to pass us, as with this thread-printing art piece entitled On Framing Textile Ambiguities.

We’ll leave criticism of the artistic statement that [Nathalie Gebert]’s installation makes to others more qualified, and instead concentrate on its technical aspects. The piece has four frames made mainly from brass rods. Three of the frames have vertical rods that are connected to stepper motors and around which is wrapped a single thread. The thread weaves back and forth over the rods on one frame, forming a flat surface that constantly changes as the rods rotate, before heading off to do the same on the others. The fourth frame has a platen that the thread passes over with a pen positioned right above it. As the thread pauses in its endless loop, the pen clicks down onto it, making a dot of color. The dots then wend their way through the frame, occasionally making patterns that are just shy of recognizable before morphing into something new. The video below shows it better than it can be easily described.

Love it or hate it, you’ve got to admit that it has some interesting potential as a display. And it sort of reminds us of this thread-art polar robot, although this one has the advantage of being far simpler.

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Plot And Visualise Brain Data In An Artwork

June 15, 2020 by Jenny List 1 Comment

One of the most interesting streams through which we receive new projects to write about here at Hackaday comes from the intersection between technologists and artists. Those artists who straddle both disciplines bring creativity that those of us without their backgrounds can only dream of. The artist [Rosa Francesca] produced a piece called Cinematica, in which she monitored her brain waves with an EEG and from them produced on-paper visualizations with a pen plotter.

The hardware in use is an Interaxon Muse EEG headband read through the Muse Monitor app, and some code to drive an Evil Mad Scientist AxiDraw V3 plotter via its serial port. The write-up goes in some depth into the different types of brain waves, explaining her choice of monitoring gamma and theta waves for her source data. The result is a series of repeating shapes that vary with the brain waves of the wearer, creating drawings that are both pleasing and unique.

If you’re interested by the Muse headset used in this artwork, you might find a teardown we covered a few years ago to be of interest. And if you’re tempted by the plotter, you can always try making your own.

Thanks, @tanurai for the tip!

Conduit, Birdhouse, And Skateboard Become Giant Pen Plotter

May 23, 2020 by Elliot Williams 3 Comments

If you think you need fancy parts to build a giant robot drawing machine, think again! [Cory Collins] shows you how he built his Big-Ass Wall Plotter v.2 out of stuff around the house or the hardware store, including electrical conduit, gang boxes, scrap wood, and skateboard bearings, alongside the necessary stepper motors, drivers, and timing belt. (You should consider having this trio of parts on hand as well, in our opinion.) With a span of 48″ (1.2 m) on a side, you probably don’t have paper that’s this big.

And while the construction is definitely rough-and-ready, there are a ton of details that turn this pile of parts into a beautifully working machine in short order. For instance, making the rails out of electrical conduit has a few advantages. Of course it’s cheap and strong, but the availability of off-the-shelf flanges makes assembly and disassembly easy. It also hangs neatly on the wall courtesy of some rubber cuphooks.

Note also the use of zip-tie belt tensioners: a simple and effective solution that we heartily endorse. [Corey] makes good use of custom 3D printed parts where they matter, like the compliant pen holder and linear mechanism for the z-axis, but most of the mechanical accuracy is courtesy of wooden shims and metal strapping.

[Corey] uses the machine to make patterns for his paper sculptures that are worth a look in their own right, and you can see the machine in action, sped up significantly, in the video below. This is the perfect project if you have a DIY eggbot that’s out of commission post-Easter: it reuses all the same parts, just on a vastly different scale. Heck, [Corey] even uses the same Inkscape Gcodetools extension as we did in that project. Now you know what we’re up to this weekend.

Can’t get enough pen plotters? Check out this one that lets you write whatever you want!

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