You can 3D print this tactile graphics slate
Most Braille embossers can produce low-resolution tactile graphics by reducing the space between adjacent lines and character cells, making it possible to emboss continuous lines of dots. But designing these graphics is a tedious process because you get no incremental tactile feedback until you emboss them. It would be nice to have something more tactile to work with when prototyping the graphics, before inputting them into the software.
I designed a 3D printable Braille slate that lets you create this kind of tactile graphic manually. To my knowledge, it’s the only Braille slate that has embossing holes “in between” the rows and columns of the cells.
The slate is sizes for a 3x5 index card. Like a typical commercial braille slate, it has cutouts for 6-dot braille cells and a backing plate for embossing proper dots. But unlike commercial slates, there is another column of dot positions in between each character cell, and a row of dot positions in between the braille rows. This allows you to make continuous pixel art shapes on a consistent grid. In order to make this work, I needed to use a dot spacing where the space between the braille cells is a multiple of the dot spacing within the cells. Surprisingly, this isn’t true for most Braille standards, but it is true of the California sign braille standard which has a 2.5mm spacing.
This slate can be used with a typical stylus, but some styli may be too fat to emboss the dots in the narrow rows and columns between cells. I made a stylus using a 1.4 by 10mm dowel pin and a 3D printed holder which fits easily.
You can find the printable files below, or on the Thingiverse page:
These are designed to be aligned by placing the cover over the base, with the pegs in the corners of the base inside holes in the cover. After aligning, permanently join the pieces. You can use hot glue, or simply heat something up and flatten off the alignment pegs. These will “rivet” the halves of the slate together.
I also created some small markers which can be placed temporarily into holes on the top of the slate. These markers can help you remember where you embossed different graphical features.
I’ve named this the Pixel Art Slate after a visual medium that has a lot in common with this style of tactile graphics.
Pixel art is a low-resolution digital art medium that evolved in the 1970s and 1980s and remains popular today. Because of the low resolution and limited color palette of early computers and game consoles, pixel artists would manually edit each blocky image pixel by hand - sometimes drawing them out on graph paper. Although these limitations don’t exist with most modern hardware, people continue to appreciate the aesthetic of pixel art and artists continue to find its limitations complement their creative process.
The OpenSCAD source code for generating the slate is available on GitHub.
by Troy