A wormwheel tooth form is generated from a hob with trapezoidal shaped teeth, which I don't think would be reproduced by simply bending the worm into a circular shape.

See this video of how they are actually made http://pounceatron.dreamhosters.com/shop/hob/hobbing-gear.mp4

I can't think how you would faithfully recreate this in MoI or any other CAD come to that without quite a bit of work.

 

Martin (2).

Here is a way to make a simple helical gear in Catia, starting from a spur gear. Just add the rotation angle psi, to match the worm.
Should be easy to do, in MoI. It is not "single enveloping worm gearing," as the gear does not wrap around an arc of the worm in a semi-circular arc curve.

http://gtrebaol.free.fr/doc/catia/helical_gear.html

The site links to how to make a worm, and how to make a spur gear.

It explains the relatively simple math.

For "double enveloping worm gearing," the worm wraps around an arc of the gear, as well. It is much more mathematically complicated.
An example is the "cone drive."

The mp4 does not play for me, with Real Player. VLC did play it. The avi file worked in Real Player.

Ok thanks guys.
I made it..
I used the Gear-Script. It was the simplest way to do it, and it works!!! :-)

Layerheigh 0.15mm

Here's a gear I made from an old DXF file I had on my computer.
I extruded the outline and then used the Twist tool to make the gear into a helical tooth form and this should be the same as the helix angle of the worm so as to allow the axes of the worm and wheel to be perpendicular to one another.


Martin (2).

Hi BlackBird, that's cool that it's working!

- Michael

Did Flow for the arbitrary enveloping radius, then did the twist.
Finally got it to be a solid.