For 2D, I tried Inkscape and Gimp.
For 3D, I tried OpenSCAD, Fusion360, and SolidWorks.
What is Spirograph....
"Spirograph is a geometric drawing toy that produces mathematical roulette curves of the variety technically known as hypotrochoids and epitrochoids.
It was developed by British engineer Denys Fisher and first sold in 1965."
-from Wikipedia
Simply speaking, it is a tool that looks like
and that draws this kind of cool things
You can see how it works from wikipedia although the operation of the actual toys are not exactly the same as the case in that page.
To get the saw-toothed tools using Inkscape, go and choose: Extensions>Render>Gear>Gear,
and then choose the number of teeth, tooth size, unit, etc.
Live preview makes it easy to see how the shape changes as you adjust those numbers.
To keep all the holes in the same size even under some modifications, instead of duplicating, I cloned a circle several times.(Edit>Clone>Create clone)
The only thing to care is whether it can run around smoothly or not.
(Since the numbers of teeth should be integers, spirograph always return to the starting point no matter what.)
So I adjusted only the size of teeth to check if it runs smoothly.
Here is the spirograph.svg file, but the original small circle lost its control over its clones after saving the file, and then re-open it. I should figure out how to handle this.
I learned via several youtube tutorials such as lapdest, lamp shade, etc. Unfortunately, I lost all the files I designed at some point, so here I have designed a simple spinner.
1. Create a sketch, and using circle and line function, draw the shape. It's easier to start at the origin.
2. Stop sketch, choose the region to extrude, and then extrude.
3. Click the upper plane, and then create a new sketch.
4. This way, I can get a sketch of the shape without all the extra lines and circles. Save it as a dxf file.
Download file here to make a small spinner for small kids! (using bolt and nut)
