question about functional gear modification(shift, stub and width)

[myh051305]

I'm new in this forum and send my best wishes . :)
I have some questions while creating a pair of non-circular gear by Gearotic2 using functional option.  Have a look at the polar file.

First, the preset value of 'width' is 0.52 or not? Sorry for that I can't remember whether I've changed it. If 0.52, does it mean that the tooth thickness is 0.48 and the tooth groove width is bigger? will it influence the meshing of gears?

second, my design demands  mod=1 and teeth number=13, so there is gear root undercut calling for modification. When I change 'shift' to 0.2 for both wheel and pinion, the teeth overlap with others. It seems like that it doesn't auto-change the distance of two axis. Should i change the 'stub' ? Er... I don't understand what does it mean. :-[ 
Or just move one gear to find the true distance of axis, but how to make sure the distance is right?  I must know accurate distance and let gear meshing well.

18 teeth performs very good but i need 13 teeh :P
My graduation project need you help :-*

regards,

[ArtF]

Hi:

  The gears are made by virtual hobbing. The Width setting is the width of the hobbing gear, so it makes the space larger on the gear. This generally makes them a bit looser for a better fit. Typically, a .51 - .53 may be required for many functional gears.

  When you select a shift, you should select a stub on the mating gear. I dont recommend any undercut for a functional
unless you actually have trouble with mesh, so Id stick with .52 on the hob, and a shift of 0 and stub of 1.

  If they mesh OK at that, Id stick with it. But the program will assume a shift on one is matched to a stub on the other
for the same center distance...

Art

[myh051305]

Hi Art: 
      thanks for your answer :)

      Er...So it means if one gear select 'shift' and 'stub' as 0.1 & 1, the other should be 0 & 0.9 to be matched. And the center distance will remain the same. 

      for example , the initial 'shift' and 'stub' is both 0 & 1, and center distance is 10. When i change them to 0.1 & 1 and 0 & 0.9, they will  still mesh well and the center distance remains 10 for real model ?
     
regards.

LM

[ArtF]

Hi:

>>Er...So it means if one gear select 'shift' and 'stub' as 0.1 & 1, the other should be 0 & 0.9 to be matched.

No, it means if shift/stub is set to .1 & 1, the other should be -.1 & 1

Stub shouldnt be changed for meshing ( or for most purposes really. But when used it doesnt have to be matched,
the shift doesnt HAVE to be, but if not, the center distance wont be correct. For Non circular gears, the center distance
shouldnt be changed..its inherant to the shape.

Art