Large Gears template anyone?

I need to make gears that are approx. 4 feet in diameter for a float in a parade.  The gears will line the perimeter of the truck and are going to be made out of 3/4" plywood with metal bracing on the teeth to prevent the plywood from chipping and attached to a plywood background.  It would be awesome if we could alternate 4 foot gears with 3 1/2 or 3 foot gears for visual interest.  It needs to look childlike - so we are not using sawteeth.  I'm going to try to attach a picture with our logo for ideas.  Any help with designing a template or where I could go to get measurements would be appreciated!  Thank you!

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boort6 years ago
I'm sure that you have your parade float built by now but if you need to make gear templates in the future check out http://www.gearotic.com/. This progarm will let you build fantastic, usable, gear trains that can then be cut on a CNC or printed out and cut by hand on a scrollsaw, bandsaw, etc...

Jayefuu7 years ago
I'm pretty sure this is exactly what you're after, though I haven't tested to see if it works to that size:

Nice link.
 Agreed. Wood gears were what came to mind immediately/
orksecurity7 years ago
I'd suggest starting with a picture or sketch of a suitable gear, and using graph paper (traditional), a pantograph (also traditional) or an enlarging copier or a projector (lazy) to enlarge it appropriately.

Graph paper is probably the simplest approach for something this large. Draw a grid on the original picture, a much larger grid on the plywood, and freehand-copy shapes from square to square.