When mass-printed holograms appeared on magazines in the 1980s they were a huge novelty, before degrading to the level of kids’ stickers in the years since. At the time they were seen as not for ordinary people to make, but the truth is they can be created without lasers or an optics lab. [Jordan Matelsky] is here to show us how they can be made using as humble a device as a pen plotter.
The effect of an interference pattern from a set of fine lines in a thin film can be demonstrated at its simplest with an oily finger and a mobile phone screen, and once he’s demonstrated that he takes us through some of the theory involved in shifting the light to make an image. There are some false starts with different materials, but eventually he shows us some finished holograms scribed on the polycarbonate of a CD case. It seems you really can make a hologram with a pen plotter. If these images interest you, we’ve looked deeper into the subject in the past. Meanwhile, one of the plotter-scribed holograms can be seen below. Continue reading “Holograms, From Your Plotter”→
The build relies on a unique motion system, wherein two NEMA 17 stepper motors drive either side of the linkage to control the position of the end effector—in this case, a pen carriage. By controlling the position of each side of the mechanism, it’s possible to move the pen through XY space. Running the show is an Arduino Nano, fitted with a GRBL shield and appropriate stepper motor drivers.
The magnetic tool changer is particularly nifty, too. It allows the plotter to grab a different ink at will to add more color to the drawing. It’s well-designed, with the plotter able to change inks without losing accuracy or otherwise fumbling the switchover. The plotter uses Muji ball point pens, which are available in a range of colors and draw with slick, clean lines. It’s also quite a fast plotter, thanks in part to [András]’s efforts to keep the pen carriage light by using a smart mechanism to offload the pen lifting actuator to the main body.
[András] has plans available, but you’re going to have to pay for them. Still, it’s always nice to see a new machine in the wild. Video after the break.
[Teddy Warner]’s GPenT (Generative Pen-trained Transformer) project is a wall-mounted polargraph that makes plotter art, but there’s a whole lot more going on than one might think. This project was partly born from [Teddy]’s ideas about how to use aspects of machine learning in ways that were really never intended. What resulted is a wall-mounted pen plotter that offers a load of different ‘generators’ — ways to create line art — that range from procedural patterns, to image uploads, to the titular machine learning shenanigans.
There are loads of different ways to represent images with lines, and this project helps explore them.
Want to see the capabilities for yourself? There’s a publicly accessible version of the plotter interface that lets one play with the different generators. The public instance is not connected to a physical plotter, but one can still generate and preview plots, and download the resulting SVG file or G-code.
Most of the generators do not involve machine learning, but the unusual generative angle is well-represented by two of them: dcode and GPenT.
dcode is a diffusion model that, instead of converting a text prompt into an image, has been trained to convert text directly into G-code. It’s very much a square peg in a round hole. Visually it’s perhaps not the most exciting, but as a concept it’s fascinating.
The titular GPenT works like this: give it a scrap of text inspiration (a seed, if you will), and that becomes a combination of other generators and parameters, machine-selected and stacked with one another to produce a final composition. The results are unique, to say the least.
Once the generators make something, the framed and wall-mounted plotter turns it into physical lines on paper. Watch the system’s first plot happen in the video, embedded below under the page break.
This is a monster of a project representing a custom CNC pen plotter, a frame to hold it, and the whole software pipeline both for the CNC machine as well as generating what it plots. Of course, the journey involved a few false starts and dead ends, but they’re all pretty interesting. The plotter’s GitHub repository combined with [Teddy]’s write up has all the details one may need.
It’s also one of those years-in-the-making projects that ultimately got finished and, we think, doing so led to a bit of a sigh of relief on [Teddy]’s part. Most of us have unfinished projects, and if you have one that’s being a bit of a drag, we’d like to remind you that you don’t necessarily have to finish-finish a project to get it off your plate. We have some solid advice on how to (productively) let go.
Plotters aren’t as common as they once were. Today, many printers can get high enough resolution with dots that drawing things with a pen isn’t as necessary as it once was. But certainly you’ve at least seen or heard of machines that would draw graphics using a pen. Most of them were conceptually like a 3D printer with a pen instead of a hotend and no real Z-axis. But as [biosrhythm] reminds us, some plotters were suspiciously like typewriters fitted with pens.
Instead of type bars, type balls, or daisy wheels, machines like the Panasonic Penwriter used a pen to draw your text on the page, as you can see in the video below. Some models had direct computer control via a serial port, if you wanted to plot using software. At least one model included a white pen so you could cover up any mistakes.
If you didn’t have a computer, the machine had its own way to input data for graphs. How did that work? Read for yourself.
Repairing vintage computers is bread-and-butter for many of us around here. The machines themselves tend to be fairly fixable, assuming spare parts are available and there hasn’t been too much physical damage. Peripherals can be another matter, though. Since they interface with the real world they can have more esoteric problems that aren’t always solvable. [joekutz] was handed just such a device in the form of a CE-150 docking station for a Sharp PC1500 Pocket Computer, which has a plotter built in. Here’s his “tip” for getting plotters like these working again.
The first step here is to disassemble the original, dried out pens to scavenge a few of the parts. The outer case needs to be kept so that it can be put back into the plotter, and a small O-ring is saved as well. To replace the dried-out tips [joekutz] discards the original tips and replaces them with tips from a common ink pen, using shrink wrap tubing to help fit the pen’s tip into the original plotter cylinder. He also takes the ink from the pen to fill the plotter’s cartridge, completing the surgery on the multi-colored plotter and bringing it back to life.
There’s something uniquely satisfying about a pen plotter. Though less speedy or precise than a modern printer, watching a pen glide across the page, mimicking human drawing, is mesmerizing. This project, submitted by [Jacob C], showcases the Incrediplotter, a brilliant repurposing of a 3D printer built by him and his brother.
Starting with a broken 3D printer, [Jacob C] and his brother repurposed its parts to create a voice-controlled pen plotter. They 3D-printed custom components to adapt the printer’s framework for plotting. An STM32 Blue Pill running Klipper controls two TMC2208 motor drivers for the x- and y-axes, while a small standalone servo manages the pen’s height.
The unique twist lies in the software: you can speak to the plotter, and it generates a drawing based on your prompt without needing to select an image. The process involves sending the user’s voice prompt to Google Gemini, which generates an image. The software then converts this image into an SVG compatible with the plotter. Finally, the SVG is translated into G-Code and sent to the plotter to start drawing.
Thanks to [Jacob C] for sharing this impressive project. It’s a fantastic example of repurposing a broken machine, and the voice-to-image feature adds a creative twist, enabling anyone to create unique artwork. Be sure to check out our other featured plotter hacks for more inspiration.
If you’re working with a microcontroller that reads a sensor, the chances are that at some point you’re faced with a serial port passing out continuous readings. The workflow of visualizing this data can be tedious, involving a cut-and-paste from a terminal to a CSV file. What if there were a handy all-in-one serial data visualization tool, a serial data oscilloscope, if you will? [Atomic14] has you covered, with the web serial plotter.
It’s a browser-based tool that uses the WebSerial API, so sadly if you’re a Firefox user you’re not invited to the party. Serial data can be plotted and exported, and there are a range of options for viewing. Behind the scenes there’s some Node and React magic happening, but should you wish to avoid getting your hands dirty there’s an online demo you can try.
