Planet Arduino

We’ve been seeing an influx of repurposed 3D printers recently. Thrifty hackers have been leveraging cheap 3D printers as a way to bootstrap their builds, on everything from laser engravers to pick and place machines. There’s nothing wrong with that, and honestly when you can get a cheap 3D printer for less than the cost of the components separately thanks to the economies of scale, you’d be foolish not to.

But there’s still something to be said for the classic RepRap mentality of building things using printed parts and smooth rods. Case in point, the largely 3D printed plotter that [darth vader] sent in for our viewing pleasure. This isn’t somebody sicking a pen on the extruder of their open box Monoprice special, this is a purpose built plotter and it shows. In the video after the break you can see not only how well it draws, but also how large of a work area it has compared to a modified 3D printer.

If you know your way around a 3D printer, most of it should look pretty familiar to you. Using the same GT2 belts, steppers, end stop switches, and linear bearings which are ubiquitous in 3D printers, it shouldn’t be difficult to source the parts to build your own. It even uses a Mega 2560 with RAMPS 1.4 running Marlin 1.1.9 for control.

The biggest difference is the physical layout. Since there’s no heavy hotend or extruder assembly to move around, the plotter has a cantilever design which gives it far greater reach. As it only needs to sightly lift the pen off the paper, there’s no need for a complex Z axis with leadscrews either; a simple servo mounted to the end of the arm is used to raise and lift the pen. We especially like the use of a tape measure as strain relief for his wiring, a fantastic tip that we (and many of you) fell in love with last year.

While it’s hard to beat just tossing a pen onto the business end of your desktop 3D printer in terms of convenience, we think it’s pretty clear from this build that the results don’t quite compare. If you want a real plotter, build a real plotter.

In 2024, the Braille system will have been around for 200 years. What better way to mark the occasion than with an open source project devoted to making embossing equipment affordable for the visually impaired? This long overdue cause became the plight of [ccampos7], who couldn’t find a DIY embosser kit and set out to build one himself.

While other embossers forcibly punch the letters in one go, OpenBraille takes a more gradual approach to ensure a clean impression with a rolling motion. Paper is placed between a mechanical encoder with moving pins and a dimpled roller that provides resistance and a place to land. The embossing head is driven by an Arduino Mega and a standard RAMPS board, as the rest of the system relies on Cartesian movement.

The encoder mechanism itself is pretty interesting. A micro servo drives a 3D printed wheel with three distinct tracks around half of the edge. The peaks and valleys encoded in these plastic tracks actuate the embossing pins, which are made from nails embedded through the sides of hex nuts. There’s a quick demo of the encoder movement after the break, and another video of it in action on the OpenBraille Facebook page.

[ccampos7] has all the files up on Thingiverse and plans to post the software soon. You should also check out this compact embosser that was recognized in the first round of the 2017 Hackaday Prize which is a nice all-print Braille concept.