# Drawing Gear in CAD



## tup48

This is for those interested in drawing gears in a CAD program. 
Check this out. www.cartertools.com/involute.html 
Here are two Pix. Of a gear that I did using the directions found here.

Richard


View attachment Gear2.bmp


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## Dan Rowe

Richard,
Yes that is a very good write up of how to use the old drafting board methods with CAD. I devised a very similar system but never made any attempt to write the work up. The problem with the system is it is a bit tedious and time consuming how ever it really made the gear math work in my head.

There are a free gear resources on the web that I have found for involute curves or approximations of involute curves.

The Rush Gear site has 2D and 3D gears for download. The curves are really circular segments which is a reasonable approximation of the involute curve.
http://www.rushgears.com/Tech_Tools/PartSearch5/partSearch.php?gearType=SPUR

Emachine shop has a gear module in the free software which will generate 2D CAD exports.
http://www.emachineshop.com/

At hobbing.com there is a free CAD library of gear profiles from 10-200 teeth. 
http://www.hobbing.com/cadlib/index.html

Dan


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## kvom

I'd recommend the 'Gear Template Generator' from http://woodgears.ca/gear/index.html

You can design the gear you want and export it to DXF. It also generates ring gears and racks.


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