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.

Panasonic wasn’t the only game in town, either. Silver Reed — a familiar name in old printers — had a similar model that could connect via a parallel port. Other familiar names are Smith Corona, Brother, Sharp, and Sears.

Since all the machines take the same pens, they probably have very similar insides. According to the post, Alps was the actual manufacturer of the internal plotting mechanism, at least.

The video doesn’t show it, but the machines would draw little letters just as well as graphics. Maybe better since you could change font sizes and shapes without switching a ball. They could even “type” vertically or at an angle, at least with external software.

Since plotters are, at heart, close to 3D printers, it is pretty easy to build one these days. If plotting from keystrokes is too mundane for you, try voice control.

These days, everyone’s got a million different devices that can take a passable photo. That’s not special anymore. A camera that draws what it sees, though? That’s kind of fun. That’s precisely what [Jens] has built—an instant sketch camera!

The sketch camera looks like a miniature drawing easel, holding a rectangular slip of paper not dissimilar in size to the Polaroid film of old. The 3D-printed frame rocks a Raspberry Pi controlling a simple pen plotter, using SG90 servos to position the drawing implement and trace out a drawing. So far, so simple. The real magic is in the image processing, which takes any old photo with the Pi camera and turns it into a sketch in the first place. This is achieved with the OpenCV image processing library, using an edge detection algorithm along with some additional filtering to do the job.

If you’ve ever wanted to take Polaroids that looked like sketches when you’re out on the go, this is a great way to do it. We’ve featured some other great plotter builds before, too, just few that are as compact and portable as this one. Video after the break.