Ruler Compass
thingiverse
If you have a metal ruler, simply use this design to turn it into a large compass instantly. I utilized a 40" ruler from Harbor Freight for my project. One end of the ruler is pinned securely to the work surface. Next, adjust the movable part so that its length equals the radius of the circle you want to draw. Once adjusted, insert a pencil into the hole in the movable part and start drawing your circle. This clever device was designed using Tinkercad's online platform. Feel free to edit it directly at https://www.tinkercad.com/things/3OMXow3RsqJ.
With this file you will be able to print Ruler Compass with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Ruler Compass.