Sanddrag,
With this web utility you will be able to generate accurate DXF drawings of ANY gear you will need. The laser should be able to directly import the DXF file you create and go to town on your new gears. There is also a provision for "offset" that would be the value of the laser diameter of cut.
I have used this, you will like it, and learn gear terminology too!
http://sinfor.lcs.mit.edu:8180/pcbmill/gears
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