Multicolor Drawbot Highlights Importance Of Limit Switches

April 15, 2022 by Lewin Day 5 Comments

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.

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Fumik: An Arduino Wall Drawing Robot Jellyfish

March 10, 2022 by Al Williams 16 Comments

If you’ve ever wanted to build a large format plotter but didn’t have the floor space, maybe put it up against the wall and make it cute. That’s the idea behind Fumik, the wall-drawing robot. As you might expect, the little device is just a motion base with a pen. We hope there’s paper against the wall since not everyone wants computer-generated art on their drywall.

The maximum size is apparently 5 m wide by 3 m tall, plenty of room to express yourself. The controller is an Arduino Mega, and stepper motors with a CNC shield drive the whole assembly. Interestingly, the motor and electronics are all onboard the jellyfish itself, rather than the wall.

The device only holds one pen at a time, but you can draw with one color and then manually change the pen. The files on GitHub are good, but you’ll need to intuit some of the mechanics from the videos. However, since it uses off-the-shelf hardware, it should be pretty easy to figure it out. This looks like a cheap and cheerful wall plotter, and the results speak for themselves.

We have seen similar wall plotters. More than once, even.

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Keebin’ With Kristina: The One With The Ballpoint Typewriters

February 10, 2022 by Kristina Panos 7 Comments

So you want to minimize finger movement when you type, but don’t have three grand to drop on an old DataHand, or enough time to build the open-source lalboard? Check out these two concept keebs from [SouthPawEngineer], which only look like chord boards.

Every key on the home row is a five-way switch — like a D-pad with straight down input. [SouthPawEngineer] has them set up so that each one covers a QWERTY column. So like, for the left pinky switch, up is Q, right is A, down is Z, and left is 1. Technically, the split has 58 keys, and the uni has 56.

Both of these keebs use KB2040 boards, which are Adafruit’s answer to the keyboard-building craze of these roaring 2020s. These little boards are of course easy to program with CircuitPython, which supports KMK, an offshoot of the popular QMK. Thanks for the tip, [foamyguy]!

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Servo Plotter Needs Nothing Exotic

January 5, 2022 by Al Williams 28 Comments

Although the widespread use of 3D printers has made things like linear bearings and leadscrews more common, you still can’t run down to your local big-box hardware store and get them. However, you can get drawer slides and any hobby shop can sell you some RC servos. That and an Arduino can make a simple and easy plotter. Just ask [JimRD]. You can also watch it do its thing in the video below.

Of course, servos aren’t usually what you use in a plotter. But the slides convert the rotation of the servo into linear motion. One servo for X and one for Y is all you need. Another microservo lifts the pen up and down using a hinge you could also get from a hardware store.

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Arduino Drives Faux Spirograph

December 10, 2021 by Al Williams 11 Comments

The holidays always remind us of our favorite toys from when we were kids. Johnny Astro, an Erector set, and — of course — a Spirograph. [CraftDiaries] has an Arduino machine that isn’t quite a Spirograph, but it sure reminds us of one. The Arduino drives two stepper motors that connect to a pen that can create some interesting patterns.

The build uses a few parts that were laser cut, but they don’t look like they’d be hard to fabricate using conventional means or even 3D printing. The author even mentions you could make them out of cardboard or foamboard if you wanted to.

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Handwriting Robots Are Sending Snail Mail

October 30, 2021 by Matthew Carlson 40 Comments

As a kid, you might remember taking a whole fistful of markers or crayons, gently lining them all up for maximum contact, mashing them into the paper, and marveling at the colorful multitude of lines. It seemed like an easy way to write many times more things with less effort. While not quite the same idea but in a similar vein, [Aaron Francis] shared an experience of creating handwriting robots to write thousands of letters.

Why did [Aaron] need to write thousands of letters? Direct mailing, of course! If you were sending someone a letter, if it looked handwritten they’re much more likely to open it. What better way to make it look handwritten than to use a pen rather than a printer? They started off with Axidraw, a simple plotter made by EMSL. Old laptops controlled a few plotters and they started to make progress. As with most things, scale became tricky. Adding more plotters just means more paper to replace and machines to restart. An automated system of replacing paper is fiendishly difficult so they went for a batching system. A sheet of plywood that can hold dozens of sheets of paper became the basis of a new mega-plotter. 3D printers and laser cutters helped make adapters and homing teeth. A Raspberry Pi replaced the old laptops and they scaled up to a few machines.

All in all, a pretty impressive build. If you’re looking to dip your toes into the plotting water, this pen plotter is about as simple as you can get.

Automate Your Graffiti With The Graffomat!

September 30, 2021 by Jim Heaney 30 Comments

In Banksy’s book, Wall and Piece, there is a very interesting quote; “Imagine a city where graffiti wasn’t illegal, a city where everybody could draw whatever they liked…”. This sounds like it would be a very exciting city to live in, except for those of us who do not have an artistic bone in their body. Luckily, [Niklas Roy] has come up with the solution to this problem; the Graffomat, a spray can plotter.

The Graffomat is, in its creator’s own words, a “quick and dirty graffiti plotter.” It is constructed primarily from wood and driven by recycled cordless drills that pulls string pulleys to move the gantry. The Arduino Nano at the heart of the Graffomat can be controlled by sending coordinates over serial. This allows for the connection of an SD card reader to drip-feed the machine, or a computer to enable real-time local or over-the-internet control.

We are especially impressed with how [Niklas] handled positional tracking. The cordless drills were certainly not repeatable like a stepper motor, as to allow for open-loop control. Therefore, the position of the gantry and head needed to be actively tracked. To achieve this, the axes are covered with black and white striped encoder strips, that is then read by a pair of phototransistors as the machine moves along. These can then be paired with the homing switches in the top left corner to determine absolute position.

Graffomat is not the first automated graffiti machine we’ve covered. Read here about the robot that painted murals by climbing smokestacks in Estonia.

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