Need Help!- need way to cad gears

[Banana Jack]

ok so i've been researching ways to draw gears on a cad program. i know people say don't bother getting the exact involute for cading gears, but i'm going to try printing these on a 3d printer so i need the exact shape.
I'm rather new to the whole cad thing, so I may be missing something that's really obvious.
i know some program have a built-in feature, where you just plug in parameters and out pops a gear, and some have add-ons or features (autocad w/ autolisp) that allow you to do this. You can do it yourself, using THIS method, but it's an 'approximate' involute and it doesn't give you the fillet at the base of each tooth. in that link, he mentions using polar coordinates to achieve the involute curve, but i can't find a good way to do that, unless inventor has a feature where i can plug in an equation and it will graph me the line/curve. (i haven't found one.)
Finally i decided to retry my very first method, which i should have gone further in-depth in the first place, i guess. i can make an assembly, and go to design accelerator>spur gear, then i can build a pair of spur gears. That was where i gave up on the first try. Yesterday i went back and found that i could right-click on the gears and say 'export tooth shape' hit ok, and it will open you a part file with an extruded circle and an involute curve drawn on it. That's where i'm stuck. It won't let me do what i want.

i tried revolving the curve around the circle, but it wouldn't let me. I tried copying the curve, pasting it elsewhere, and using circular pattern revolving it around a new center point, connecting the tops with lines(arcs didn't match up for some reason) but it wouldn't let me extrude the new shape. I tried opening a new sketch, then i could circular pattern the involute, but it won't let me extrude that either.

any ideas?

[tulsaturbo]

This may help:

http://woodgears.ca/gear_cutting/template.html

http://woodgears.ca/gear/

[BobWarfield]

Try this one: http://delphusa.com/index.htm

Also, if you don't like that, go to my Delicious book marks and check out the articles tagged with "gears":

http://www.delicious.com/CNCCookbook

Cheers,

BW

[neilw20]

Try
http://www.emachineshop.com/machine-...r/page507.html
Export to a dxf.

[Banana Jack]

both the woodgears and delphusa programs look pretty nice, but i think i'll end up using the $26 woodgears version if i can't figure out how to do it inventor.
bobwarfield - i did try the rushgears.com generator, but i couldn't import the files into autodesk inventor. have you had any experience with that? i enjoyed those articles on gears, by the way.

although...with the free emachineshop program and the gear design wizard...i'll have to give that a shot.

[BobWarfield]

Sorry, just got Inventor and haven't played with it much yet.

Cheers,

BW

[Skuce]

What about Helical gears that mesh with a worm?

[MarkWink]

just stumbled accross this program... check the tutorials - lots of outputs options

http://www.gearotic.com/

[jeff 888]

In the assembly of a part there is something called design accelator built in and from there you can generate gears or your other option is I have been using whats called an iPart and with this you can just enter in what you need/want and it will generate the gear (I can email you this file if you would like and show you how to use it)