Sometimes I would come across situations when I would wish I had a protractor to measure angles in my projects. I had been using transparent plastic protractors all these while. They were cheap. Unfortunately, these were rather soft and could get scratched very easily. Some of them were brittle and would end up as broken pieces when I was not careful. Then I would have to buy another one. What a nuisance! And I would not have a protractor available when I needed to check an angle. What a frustration!

Although they were cheap, the diy nature in me wanted to create one for myself out of available materials that I had on hand. After all, I don’t use it very often. Well, I had polished aluminium hard drive aluminium disk available that I picked up sometime ago. And most important of all, I had a cnc machine that I could use for engraving.

Creating the outline of the protractor and its graduated lines was easily done with my Autocad LT 2000 drawing software. The challenge was to engrave the numbers, because after the lines were drawn and file saved as a .dxf file, it was to be converted to a gcode file by another software called dxf2gcode. The gcode file would then be translated by the cnc machine into movements for the engraving.

However, the text created by my autocad drawing software could not be converted to a path by the other software. It was simply not recognized.

I overcome this problem by drawing lines to represent the numbers. Lines were recognized. My workaround was to imitate LED digital displays, the numbers being consisting a couple of lines arranged accordingly. I just needed to draw lines to represent the numbers in my drawing program. Took me a longer time than just pressing on the number buttons on the keyboard, but eventually I was able to complete all the numbers around the protractor. The drawing software also allowed me to display the numbering spaced 10 degrees apart and also to adjust for different sizes to suit.

The video show the project of making a protractor out of an aluminium disk.