Custom Ruler 1cm Markings

Contributed by
Mark G. Peeters

Duration: 45 minutes

Level: Beginner

Resources: Computers, 3D printer

openSCAD Rulers

Add your own text to a 20cm ruler with 1cm markings. This is an openSCAD file we use with our 2nd grade students to introduce them to coding with openSCAD, 3D printing, and an online LMS. They make their own rulers to be used for the school year. You can use the thingiverse customizer if you don't have access to computers with openSCAD.

Overview and Background:

You can use this with any age group. I am only describing how we have incorporated this into our K-12 scope and sequence for technology and 3D printing. At 2nd grade we are deepening students familiarity with 3D printing and miscellaneous technology skills. The activity allows students to practice their technology skills and gain an awareness about openSCAD and 3D printing. In 2nd grade students are learning about measurement to 1cm precision, so this ruler is exactly what they need for the year. The actual slicing and printing is done by the instructor or higher grade level students. Each student gets their own ruler with their customized text.

Lesson Plan and Activity:

The lesson is a single 45 minute session in our computer lab with 2nd graders. Students download the openSCAD file and save it in their user space. It’s advisable to have them make a folder for all the files this project will create. They open the file in openSCAD and only modify three variables: text, font size, and hole size. The rest of the code is “hidden” by many blank lines and most students don’t scroll down to see the code. They change the code for the text they want in the openSCAD editor window and practice previewing the model in the 3D view. They get practice manipulating the 3D view (zoom-pan-rotate) to see their changes to the code. Depending on the text they want on their ruler they may need to change the font size. We talk about not making the font so small that the printer’s 0.4mm nozzle will not be able to print the letters. The teacher checks their model before they render the final STL file. They save the STL file to their project folder in their user space. Students indicate what color they would like the ruler printed with, and attach the STL file to the post.

Skills Learned:

Downloading to user space, file management, coding, openSCAD skills: preview window and moving the 3D object in the preview window to see it better-zoom-pan-rotate

OpenSCAD Ruler