Plotters and drawing robots are fun projects that let you create art with all the precision and perfection that computer numerical control can deliver. [TUENHIDIY] demonstrates that ably with the Multicolor DrawBot.
The build relies on a simple XY Cartesian design, using a pair of NEMA 17 stepper motors. It’s built in the typical CoreXY fashion, running GRBL firmware on an Arduino Uno.
Where [TUENHIDIY] gets creative is in the pen itself. Rather than using a simple ballpoint or marker, instead, a retractable multicolor pen is used instead. With the multicolor pen on board, [TUENHIDIY] notes the importance of limit switches in the design. These allow the the ‘bot to make multiple passes, each time in a different color, to build up a multicolor image. Without the limit switches in place, it would be impossible to line up each following pass.
We’d love to see the build taken even further with a servo-based system for switching colors automatically. As it is, though, [TUENHIDIY] has a capable plotter that can deliver tidy multicolor artworks.
One of the more curious applications of plotters of late are those used to send faux handwritten letters through the postal system. Video after the break.
Continue reading “Multicolor Drawbot Highlights Importance Of Limit Switches”
Fire up those 3D printers because if you’re like us, you’ll want your own PlottyBot. Still, have a pile of “thank you notes” to write from recent winter holiday gift exchanges? Hoping to hand letter invitations to a wedding or other significant event? Need some new art to adorn your lock-down shelter or shop? It sounds like [Ben] could help you with that.
Besides being a handsomely designed desktop DrawBot, this project from [Ben] looks to have some solid software to run it, a community of makers who have tested the waters, and very detailed build instructions. Those include everything from a BOM with links for ordering parts to animated GIF assembly for the trickier steps.
If you’d like to graduate from “handwritten” cards and letters to something poster-sized are customization tips for expanded X and Y dimensions. As we’ve included in other recent articles, one caveat to mention is the current scarcity of the Raspberry Pi Zeros that PlottyBots require. But if you have one on hand or think you’ll be able to source one by the time you’ve 3D printed all the parts, it might just be the perfect time to add another bot to your family. As a heads up, this project is self-hosted on a solar-powered server, so maybe take turns reading the complete build log.
A nice bonus if you need help drawing something suitably complex to require a robot’s help, [Ben] also created MandalGaba which looks like an awesome online tool for drawings like the ones shown above.
Elliot Williams and Mike Szczys wish Hackaday a happy fifteenth birthday! We also jump into a few vulns found (and fixed… ish) in the WiFi stack of ESP32/ESP8266 chips, try to get to the bottom of improved search for 3D printable CAD models, and drool over some really cool RC cars that add realism to head-to-head online racing. We look at the machining masterpiece that is a really huge SCARA arm drawbot, ask why Hydrogen cars haven’t been seeing the kind of sunlight that fully electric vehicles do, and give a big nod of approval to a guide on building your own custom USB cables.
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Direct download (60 MB or so.)
Continue reading “Hackaday Podcast 034: 15 Years Of Hackaday, ESP8266 Hacked, Hydrogen Seeps Into Cars, Giant Scara Drawbot, Really Remote RC Car Racing”
It’s not uncommon to find us doodling on paper as an aid to thinking, for recreation, or simply because we’re bored. But, this kind of manual labor is so last century. It’s 2019, and we should have robots to fill our notebooks with cross-hatched illustrations. Well, [Alex Weber] is way ahead of us on this account: the outstanding SCARA drawbot he created can be unleashed to draw all manner of things at his command.
The robot, named Mechpen, and pronounced “McPen”, is of a SCARA (Selective Compliance Assembly Robot Arm) design, with two parallel axes controlling the x-y movement of the arm. Robot design is always a series of trade-offs; in this case, [Alex] has sacrificed some accuracy to achieve a long reach. Two NEMA 23 stepper motors reside in the base, along with all the electronics. This makes the base a heavy 15 kg, which is good as it helps stabilize the arm during movement. The arm uses a mix of off-the-shelf and custom hardware, most of which is dotted with holes drilled to reduce the mass of the moving parts. Two 700 mm sections of the arm made from carbon fiber tubes give the drawbot a 140 cm reach — long enough to fill an A0 paper with its beautiful mechanical doodling.
The brains behind the arm are two-tiered. An Einsy RAMBo board, designed for 3D printers, controls the stepper motors. Above that, a Raspberry Pi runs Octoprint to control the ‘bot. This choice turned out to be very convenient for working around a mechanical issue: the elbow flexes too far in the Z-axis. The difference in pen height between the elbow at 90 vs 180 degrees was 20-25 mm; too much to fix with just a spring-loaded pen. The solution: use a bed-leveling algorithm designed for 3D printers. A VL6180X distance sensor measures the distance to the paper over a number of grid points, then the software moves the servo up and down accordingly while drawing to keep the pen on the paper.
Some custom-written software converts SVG graphic files to gcode suitable for printing, allows selection of different stroke and fill types, and separation of different colors into individual gcode files to be plotted with different pens.
Definitely check out the video of Mechpen in action, after the break.
Continue reading “Mechpen: SCARA Drawbot For The Big Picture”
There’s something about art. Cavemen drew on walls. People keep programming drawing robots. One we’ve seen recently is [Andy’s] Drawbot that uses WiFi and WebSockets to draw on just about any flat surface. What’s more, the Johnson County Library has a great write-up about how they built one and if you want a go at it, you’ll find their instructions very helpful. The video below is pretty inspirational, too.
What makes this build especially interesting is that it uses a drive system with two fixed points attached with suction cups. There are a variety of 3D printed parts — some just for the build and some are older parts repurposed.
Continue reading “Another Drawbot Uses A Pi And Web Sockets”
Badges come in all shapes and sizes, but a badge that draws on a stack of Post-It notes is definitely a new one. The design uses three of the smallest, cheapest hobby servos reasonably available and has a drawing quality that creator [Bart Dring] describes as “adorably wiggly”. It all started when he decided that the CNC and mechanical design world needed to be better represented in the grassroots demo scene that is the badge world, and a small drawing machine that could be cheaply made from readily available components seemed just the ticket.
Two arms control the position of a pen, and a third motor lifts the assembly in order to raise or lower the pen to the drawing surface. Gravity does most of the work for pen pressure, so the badge needs to be hanging on a lanyard or on a tabletop in order to work. An ESP32 using [Bart]’s own port of Grbl does the work of motion control, and a small stack of Post-It notes serves as a writing surface. Without the 3D printed parts, [Bart] says the bill of materials clocks in somewhere under $12.
We’ve seen similar designs doing things like writing out the time with a UV LED, but a compact DrawBot on a badge is definitely a new twist and the fact that it creates a physical drawing that can be peeled off the stack also sets it apart from others in the badgelife scene.
[Jason Allemann] built a Mindstorms Telegraph Machine that packs so many cool details that HaD is about to have a fit.
First off, It’s a drawbot able to write letters, a difficult feat given a lack of native stepper motors and the limited gear options for Mindstorms. Trying to draw letters with servos typically makes for some ugly letters. And how does the drawbot know what to write? You code them in with Morse code. The second video after the break shows [Jason]’s setup. He has a Mindstorms touch sensor with a LEGO Morse key attached to it. He simply taps on the key and the EV3 Intelligent Brick interprets his dots and dashes and translates them into letters.
Next off, [Jason]’s printer is built using one EV3 set. It’s one thing to build a cool Mindstorms robot with whatever you have in your parts bin, but the gold standard is to make a project that can be built with only one EV3 set. That way, anyone with the set can build the project. Precious few really cool projects can be built with just one set–[David Gilday]’s MindCub3r Rubik’s cube solver comes to mind. Dude, this is another one.
Last off, [Jason] breaks down how to build it, providing full LDraw building steps and EV3 code on his site. Even better, he shows how to supersize the project by adding a second EV3 brick, which can connect to the drawbot’s EV3 brick via bluetooth and serve as a standalone CW key. He shows off this part in the second video.
Icing on the cake, [Jason] even built a Morse reference book, done appropriately in 100% LEGO.
Hackaday loves innovative LEGO projects, like this game-playing robot and this LEGO exoskeleton.
Continue reading “Mindstorms Morse Key Writes To Drawbot”