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Building a DIY Pen Plotter
- Torkel 3y agoPost about pen plotter without video. Hmm, I feel cheated. Random video of old school pen plotter in action: https://www.youtube.com/watch?v=3Cd3GsZlOBg https://www.youtube.com/watch?v=3Cd3GsZlOBg My father still fondly talks about how the crispness of a true pen plot was never really matched by modern printers. Edit: he has them on a second page: https://szymonkaliski.com/projects/diy-pen-plotter https://szymonkaliski.com/projects/diy-pen-plotter Not as fast as the 1983 version though :)
- deleted 3y ago[deleted]
- CobrastanJorji 3y agoThey make a weird kids STEM toy that's a surprisingly well thought out pen plotter: https://www.youtube.com/watch?v=kSFW5ok3ROc&start=128 https://www.youtube.com/watch?v=kSFW5ok3ROc&start=128 The big arms are attached to the egg thing with two magnets, so a kid shoving their hand into the moving parts is very safe; it just falls apart. And you can see the clever arrangement of the three moving parts (axis 1, axis 2, and lift/drop pen).
- blacksmith_tb 3y agoI have a Watercolorbot[1] which is like the world's most inexact plotter. But it's a lot of fun to watch it pick up paint on the brush and try to paint a gcode version of your design (also funny to see the patterns the slicer algo uses to try and fill blocks of color). Software was always a little fiddly, but still a fun idea. 1: https://watercolorbot.com/ https://watercolorbot.com/
- deepspace 3y ago> crispness of a true pen plot was never really matched by modern printers I don't know about that. Pen plots can, at a push, achieve the equivalent of about 250dpi. Back in the early 90s, I wrote software for the first inkjet “plotter” (a wide format printer that used HP inkjet cartridges, and rasterized HP-GL commands on the fly). Even back then, we could get 600dpi resolution, and today's printers can do up to 2400 dpi.
- dekhn 3y agoThe point is generally no matter how high your DPI, if you're drawing a line using a series of points, compared to drawing a line via a vector process, the vector process will almost always look nicer (for some definition of nicer).
- Torkel 3y agoYeah… but I think what he misses is that it’s a line drawn by a pen. It has a certain analog appeal to it? Vinyl is worse in every way to lossless digital. As is an analog film camera. Or a mechanical watch for keeping time. Still though.
- mkl 3y agoMy mid-1990s Graphtec plotter has a precision of .01mm, or 2540dpi. I don't have any pens for it fine enough for that to matter though, and have yet to build a generic pen-holder (it grabs the pen with magnets...).
- deepspace 3y ago> I don't have any pens for it fine enough for that to matter though Yes, that is the issue. The finest pen you could likely get would be 0.1mm (and even that would be hard to find and expensive). That is what I based the 250 dpi on.
- zellyn 3y agoWhat is the final resulting accuracy?
- deleted 3y ago[deleted]
- Animats 3y agoMore useful is one of his references on how to build a CNC router.[1] This one covers all the usual mistakes one can make building a CNC router. (He skips the real n00b mistake - trying to use a Dremel tool in a CNC router. That never works. Dremel tools slow down or stall under load, and the CNC controller doesn't detect that, so it keeps pushing a stalled tool around.) [1] https://mattferraro.dev/posts/cnc-router https://mattferraro.dev/posts/cnc-router
- syntaxing 3y agoTo be fair, most hobby CNC tools were opened looped until more tools came out that were BLDC + zero cross detection for speed control. That being said, stalling your tool more or less means you’re just blindly cutting a part. Calculating the correct feed rate is absolutely essential for any router/milling operation.
- dheera 3y agoInstead of open loop calculations, why not just actually measure the current (or motor RPM) and do a feedback loop?
- syntaxing 3y agoMixture of motor technology, cost, and application. Take a dremel for instance, adding all these features cost money and most dremel users won’t care for it. Also certain motor technology makes it impossible to control in a meaningful fashion. If you stuck an encoder on a dremel, you’ll still have a lot difficulty maintaining the set RPM.
- dekhn 3y agothat doesn't give you step-level accuracy. Some systems do this- for example Prusa MK3 and newer don't have physical endstops, instead they monitor current. And FluidNC supports this but clearly points out you shouldn't use it for step-level accuracy.
- numpad0 3y ago
- thot_experiment 3y agoThat is one EXTREMELY overbuilt plotter, you love to see it.
- rtkwe 3y agoVery over built. A lot of the times you just see two beams that advance their respective axis because there's so little force applied by a pen.
- CobrastanJorji 3y agoFor a properly extremely overbuilt plotter, you could do what I've done: tape a pen to a 3D printer. It's a bit like building a back massager by putting a cell phone on vibrate and texting it continuously, but it's also a dang good plotter once you figure out a set of G-Code instructions that don't destroy the pen by accident. I've been thinking of taking advantage of the ability to raise the pen really high to do something crazy like use a quill and an inkwell, but I use a bed slinger printer, so figuring out an inkwell that doesn't splosh ink around everywhere or floats just over the bed is probably more work than the idea is worth.
- thot_experiment 3y agoI have a custom built plotter that paints in watercolor, I don't have a lot of good media depicting it yet, but if you're local to the Bay Area I'll have a booth at Maker Faire showing it off!
- ignite2 3y agoI'll look for you!
- CobrastanJorji 3y agoThat is really, really cool! I'm not but I look forwards to hearing more about it in the future. Really curious about how you move the brush. Pointillism? Filling polygonal regions with lines? Some sort of interesting "imitate real brushwork" algorithm? Do you do color change by swishing the brush in water? Ooo, does it mix colors? Because that'd be super fun if probably impractical.
- okamiueru 3y agoIt makes me so happy to read summaries of project like this. Thanks for sharing! I did almost the exact exercise a couple of years ago, except hand soldering the controller board together with an ESP32. It was an Core XY design with timing belts, also completely over-engineered. It suffered from hysteresis from too many plastic 3d printed parts (I only had belts, steppers, linear rails, and ball bearings). Would love to do it again some day, but properly. Definitely going for a pre-built CNC controller board, as that was a pain. P̶e̶r̶h̶a̶p̶s̶ ̶a̶ ̶M̶a̶c̶h̶3̶ ̶o̶r̶ ̶M̶a̶c̶h̶4̶ ̶b̶o̶a̶r̶d̶ Probably just make a PCB version, unless anyone know of a general ESP32 based 3-axis GRBL board with SD card?
- wdfx 3y agoGrbl on esp seems to be not really a thing. You can however go the Arduino nano and el-cheapo CNC board + drivers for less than $20 or so. You can usually also plug in an Hc-05/hc-06 Bluetooth module if you want it wireless. Beware that some of the cheapest CNC boards may have some dodgy wiring on the MS lines https://youtu.be/U839EbPw-A8?si=0SvVgZL0tX3j4P4K https://youtu.be/U839EbPw-A8?si=0SvVgZL0tX3j4P4K I've just completed a project using these parts https://doug.lon.dev/2023/09/19/astro-camera-mount.html https://doug.lon.dev/2023/09/19/astro-camera-mount.html
- deleted 3y ago[deleted]
- hugs 3y ago"Grbl on esp seems to be not really a thing." Grbl on ESP32 absolutely is a thing. I've been using it to drive my robots for years. https://github.com/bdring/FluidNC https://github.com/bdring/FluidNC
- wdfx 3y agoOh that's interesting, I didn't seem to find that when I was researching my project. Definitely worth a look.
- dekhn 3y ago
- batterylow 3y agoNice project! I was gifted a pen plotter [1] a while ago and have enjoyed it so far. I would love to build one that supports larger pieces. [1] https://shahinrostami.com/articles/my-pen-plotter-setup/ https://shahinrostami.com/articles/my-pen-plotter-setup/
- ignite2 3y agoIf you want the simplest plotter you can make: https://www.brachiograph.art/en/latest/ https://www.brachiograph.art/en/latest/
- wdfx 3y agoThat's really cool. I have a few of those servos laying around waiting for a project :)
- Lalabadie 3y agoThe Makelangelo is also charmingly simple: http://www.makelangelo.com/ http://www.makelangelo.com/
- wesleychen 3y agoIt has a not-so-charming price tag (490 CAD).
- jibbit 3y agothis is fab
- crtified 3y agoThe only thing that moves more impressively fast than the dancing pens in a high-quality pen plotter, is the human supervisor of said plotter, when some rare physical fault occurs, and the mechanism starts turning your big sheet of expensive paper into a random 3D pretzel at the speed of light. It very rarely happened! and certainly, most modern equipment would have inbuilt fail-safes, but trust me, when it happened, it wasn't subtle! One of those trash-style TV shows, based around 'When Plotters Go Bad', would be - as they say - "quite the lol". Other humorous old-fashioned plotter errors included those times when human error led to half the plot being drawn directly onto the plotter's vacuum bed (e.g. sent Landscape data, while the paper was loaded Portrait). Of little consequence except shame, that one.
- Hackbraten 3y agoRelated: Franz Kafka's In the Penal Colony. Probably the ur-example of the plotter-error trope.
- app4soft 3y agoHardened CNC frame template.[0] [0] https://github.com/JMG1/PlasticSliderCNC https://github.com/JMG1/PlasticSliderCNC
- buildsjets 3y agoFor a history of some of the earliest CAD/CAM and plotters, ref. "A Possible First Use of CAM/CAD" by Norman Sanders, Chapter 4. https://inria.hal.science/hal-01526813/document https://inria.hal.science/hal-01526813/document The gist of the paper is that computer aided manufacturing was developed FIRST, and computer aided design was an offshoot of that. When they had developed their prototype CAD system, the available pen plotters could not output drawings in a high enough resolution to be used for downstream manufacturing processes. "In short, at that time computers could master-mind the cutting of metal with great accuracy using three-dimensional milling machines. Ironically, however, they could not draw lines on paper accurately enough for design purposes; they could do the tough job but not the easy one. However, one day there came a blinding light from heaven. If you can cut in three dimensions, you can certainly scratch in two. Don’t do it on paper; do it on aluminium. It had the simplicity of the paper clip! Why hadn’t we thought of that before? We simply replaced the cutter head of the milling machine with a tiny diamond scribe (a sort of diamond pen) and drew lines on sheets of aluminium. Hey presto! The computer had drawn the world’s first accurate lines. This was done in 1961."
- ray__ 3y agoWhat are the best approaches for turning an image into a plottable vector graphic?
- loskutak 3y agoI made this some time ago: https://github.com/serycjon/vpype-flow-imager https://github.com/serycjon/vpype-flow-imager
- dktbs 3y agoThere are a lot of options for this but the two I really like are https://github.com/SonarSonic/DrawingBotV3 https://github.com/SonarSonic/DrawingBotV3 and https://mitxela.com/plotterfun/ https://mitxela.com/plotterfun/ Also, vpype (https://github.com/abey79/vpype https://github.com/abey79/vpype) isn't specifically a tool for vectorizing images, but its incredibly useful for preparing vector files for plotting.
- pcblues 3y agoDad was a polymath. He used pen plotters to map out his VLSI designs in the 1980s and taught VLSI at CIT in Melbourne. I remember as a kid watching the magic as the diagram unfolded on A3 paper. I also remember my grandmother bought a four colour plotter for her home pc (Oric Atmos I think). She put herself through business systems in the 70s at night school, too. Probably enough genes there to get me into software dev :) (Edit for Atom to Atmos - twas a long time ago)