Re: CAM bugs

Elliot,

TurboCNC v3.1 has a problem interpolating when the either endpoint
of an arc is "exactly" at the 6 o'clock position. I have a fixed
executable for this, or for short files you can use the workaround of
offsetting the center point slightly.

Since Yahoo won't let me send attachments, email me offlist at:

dkowalcz at dakeng dot com

and I'll reply with the patched version. v3.1a should be out in a
few days, which includes the fix for this problem as well.

Dave Kowalczyk
Everett WA
http://www.dakeng.com

--- In CAD_CAM_EDM_DRO@y..., "Elliot Burke" <elliot@h...> wrote:
> After designing a simple part, BobCAD 17 generated the following G
code:
>
> G01 X-0.143 Y-0.895 Z-0.0932
> X+0.9 Y-0.895 Z-0.0938
> G03 X+1.589 Y-0.572 I0.0 J+0.895
>
> This should have made a line and an arc.
>
> TurboCNC was used to control a Taig mill.
>
> What it did was cut first a complete circle, then the fractional
part of the
> circle that was the arc.
>
> Imagine my surprise!
>
> Changing x center of the circle from I0.0 to I-.001 fixed the
problem.
>
> Is it likely that this is a round off error?
>
> Will I have to go through all the g-code to locate problems like
this?
>
> Darn, I had thought this was going to be easy.
>
> Elliot