While I am still thinking about putting back some blue on the Gears theme proposal for Fedora 10 (and, of course, while counting down the few days remaining until the upcoming Fedora 9 release) here is a short howto about drawing gears, so anyone can learn to make them.
In fact drawing gears is not hard at all, I cheat and use an effect included in the recently released Inkscape 0.46 (available both in F8 and F9) Effects > Render > Gears:
A few parameters to adjust (with Live Preview enabled to see their effect in real time) and we get a toothed wheel:
Now add a circle:
And use the Align and Distribute dialog to align it to the center (I used here "e;Relative to: Biggest Item"):
Then substract the circle from the wheel (you may need to upgroup once, as the Gear effect greated the wheel as a group):
Now to create spokes. Add a rectangle and align it to the center:
Duplicate the rectangle and rotate it 90°:
Select both rectangles and rotate them freely:
Select everything and do an union:
For the middle of the gear create a small circle, align it to the center and do another union:
The hole for the axis is another circle aligned to the center and substracted from the wheel:
And the first gear is done!
Another gears coupled with it must have similar teeth, so use the Gear plugin and change only the number of teeth:
And do a complex mechanism:
You may want to increase the complexity further by adding some parallel gears, which may have their own parameters (as long as they are not coupled with the initial gears):
And that was all for today! Expect a follow-up (maybe next week) about coloring those gears.