After creating the Mathologer-inspired coasters based on times tables, I wanted to see how these would work out using spirograph designs. I was pleased enough with the outcome that I am sharing these here.

A spirograph is created by rolling a small circle (radius=r) inside a large circle (radius=R). The pen is placed inside the small circle at some fractional radius=frac*r.

The gearing ratio of the two circles is defined by the first two (relatively prime) integers in the names of the STL files. So for example if the name of the file is M_N_frac_spirograph2.stl then: rM=RN and the fractional radius where the pen is placed is frac*r.

Everything gets scaled so that the outer radius of the spirograph design = 45mm.

Print the designs and the case and they should fit tightly together.

Place drink on coaster and enjoy!

Prusa

I3 MK3S

No

No

.15

100% for the coasters, 15% for the case

I have found with my printer that for the more complicated designs (for example 5131.8) I had to multiply the extrusion rate by 0.9 to prevent bulging at the center and prevent crashes. Not sure why this happens: Calibration? Slicer issues? Some type of over-extrusion is happening. Let me know if you find a better solution. Even at .9 extrusion multiplier, I used sandpaper to thin the bulge that was still present so the coaster would lay flat.