Offset Path tool creates non-parallel lines and incorrect measurements

[lucasschwartz]

Hi- 
I've used illustrator for years and never had this problem
When I offset the paths of a rectangle at -.007 inches, the resulting smaller "rectangle" does not have 90 degree corners, and the lines are not parallel with the original rectangle. 

The "align art to pixel grid" is turned off, near as I can tell. 

The original rectangle measures 7.5 by 3.5 in the transform window.
The offset "rectangle" "measures" 7.5 by 3.493...  the math on that isn't right any way one looks at it.

I'm using illustrator to create CNC cut paths, and this is really putting a wrench in the works.

Can anyone tell what is going on here?

 

 

 

 

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[brian_kelly_hahn]

It's a 5mm square that I have offset the path -0.01mm over and over using an action that only does the offset. Snap to pixels has no effect. If I change the offset to -0.1mm, there's no problem.

[pixxxelschubser]

Which Illustrator version are you using? In one of the previous versions, there was a bug that created unclean contours as soon as the contour thickness became smaller than 0.05 mm. Perhaps this also applies to the offset path?

I have not yet experienced such an error in more recent versions (nor have I heard of it).

[brian_kelly_hahn]

Currently using v28.6.

[brian_kelly_hahn]

Just updated to v29.1 and the problem is still there on a fresh document.

[thalia_8929 · Accepted solution]

Hi I was having this problem as well. My 45 degree angled rectangle was roughly .050" x .090" and it was havjgn that problem offsetting as well. Tried everything and read through this thread then fixed it. Scale up the whole shape then offset as needed then resize then scale back down once you have all the layers/offset you need.