A while ago I decided to re-work the wooden spirograph to make it a little easier to machine, to improve the finished quality and to see if I could add a few more wheels to work around and this is the result my much improved spirograph. Detail of the original version are in this post here
A key problem with the old version was break out of the ply along the spoke that also had the pen holes. OK, it didn’t adversely affect the way the cog rotate on the paper but it looked unsightly, unprofessional and wrong. The other aspects of the first design were that machining the ribs took time and the design limited the number of pen holes that could be placed on the rib.
The design of the new cogs is a single disc with pen holes laid out in a spiral so from having maybe 5 pen hole I can produce cogs of similar size with 10 holes. The other side benefit is that I can now make the diameter of the holes a little larger so 3mm rather then 2mm given the extra space.
The other design change or addition was to develop additional wheels to draw around. The first test shape I attempted was the triangle above. The tooth layout for the corners already existed but I needed a slightly different tooth profile for the straight sections. After a little trial and error with some online cog design apps, Inkscape and freestyling it I managed to produce something that works. Its a while since I set this up so can’t remember the final method but I’m fairly sure it was Inkscape. I decided to make life a little interesting for anyone using this by putting pen hole in the wheel as well.
Ok, not quite complete and maybe not the finest example but it does give a clue to possibilities – I got much better results from using larger cogs.
Having aced the triangle, I made a square wheel and an oblong; and they all have pen holes in them too.
The full set consists of 4 wheels and 12 cogs which I think should give folks a challenge to create something wonderful and amazing. What’s even better this improved spirograph is available from my Etsy shop
If you want a bit of inspiration then check out Rachel otherwise known as Spirograph Girl – if you want a world map made from spirograph shapes and patterns then look no further!
