Click on the Links to go to the web pages that simulate theses drawing functions:
This one requires you to drag the wheels with the mouse pointer
No turning at all required for this one. Just change the setting and it draws it instantly
This one you make the setting with some sliders and then click Redraw
Yet another one, but the results dont look as good on this one.
Cycloid Drawing Machine
This one you set the various points and then start the machine going
You can se the number of cogs, ther size and position and the pivot points whilst it is running. See the Help ? for changing setting
A Three-Pendulum Rotary Harmonograph Simulator
Interesting to see what a harmonograph is. Look it up in Google.
It can produce some very interesting shapes.
A single Pendulum Harmonograph on 2 wires Simulator
Again some interesting results. See the links from the page that shows a photo of the real thing