Device Details


Keyguards help individuals with limited ability to point reliably at regions of an app running on a tablet. They do this by physically separating access to specific regions of the tablet screen with rails that rise up from the surface of the tablet. In this case, the apps are associated with Augmentative and Alternative Communication (AAC).

Some AAC apps organize their content into grids with menus and message bars, above or below the grid. Others are much more creative and unpredictable in their layouts. Hybrid apps are largely grid-based but their keyguards can be enhanced by selectively exposing specific regions of the app.

The number of possible choices for tablet, tablet case, and AAC app, make it impossible to design a few keyguards that will meet everyone’s needs. To complicate matters further, users have lots of flexibility for how they organize the content in their apps. All of this is to say that users must be given control over the keyguard design. I know of only one 3D modeling tool where that is possible – without requiring that each user become an expert in 3D modeling. That tool is OpenSCAD. OpenSCAD has a “Customizer” feature that allows users to provide input to an OpenSCAD design that can shape the design to meet their specific needs.

We have created an OpenSCAD design that allows the user to identify their tablet, describe how the AAC app is laid out, describe their case, and choose a mounting method to mount the keyguard directly to the tablet or to the case. Once the keyguard is fully described you can generate and save an STL file that you can print on your 3D printer.

This is a Thingiverse Customizer design but only for grid-based apps. Free-form and Hybrid apps require greater specification and visualization than Thingiverse’s Customizer can support. For those keyguards you will need to download and install the latest version of OpenSCAD and a good text editor like Notepad++.

If you will be using OpenSCAD, the only files you need to download from here are called keyguard_v15.scad, screen_openings.scad, and case_openings.scad. All other files are just for illustration. You also need to go to to learn how to customize the keyguard.

A PDF form is provided as well for collecting and communicating the requirements for your keyguards.conditions that affect a person’s ability to use natural speech.

Keyguards are typically cut from a sheet of acrylic by a laser cutter and can be quite expensive to purchase commercially. A 3D printed keyguard has a number of benefits:

  • can be as customized as you need
  • is not limited to being flat so it can be mounted in a variety of ways
  • can be printed in a vast number of colors
  • costs less than $1 per keyguard

At that cost, you can easily have multiple keyguards for multiple app configurations.

To make a custom 3D printed keyguard, visit the Volkswitch site to and follow along with the comprehensive instructions. You’ll need to make the necessary measurements of the tablet and the app to change the OpenSCAD design parameters and generate the custom STL file for 3D printing. The OpenSCAD design file is available on Thingiverse.