G2/G3 resolution

[gnrules]

Hi Tom,
i'm trying to smooth as possible a round path of 300mm diameter.
we tried different approaches using:

-corner tolerance 0.01mm
-Beak angle: 20 deg
- facet angle:0.1 deg
-collinear tolerance: 0

both with G2/G3 and tessellated path (chordal deviation 0.0005mm) we notice some sort o facets on the outer surface of the circle.
no change with number of passes, finishing, tool speed and feed (at least not significant).


I thought was the lnear segments but also the G2 gives a similar result.
my question is: how does kflop process G2/G3 arcs? I thought it calculates a sort of time discretization adding a point every n servo cycles, but maybe i'm wrong. I was expecting a very smooth swurface from G2, but probably there are some params that influences the actual number of points generated.

Thank you very much

Best regards

Giancarlo

[gnrules]

Forgot to mention we use KLP=0.002 filter and the sound of the mill is quiet and smooth, so no vibrations are in place (also changing tool loads with no effects is a proof).

[TomKerekes]

Hi Giancarlo,

how does kflop process G2/G3 arcs? I thought it calculates a sort of time discretization adding a point every n servo cycles, but maybe i'm wrong. I was expecting a very smooth swurface from G2

It calculates points ever 90us servo cycle using 64-bit floating point sin function so from that perspective it should be very smooth.

What Version are you using?

What are your axes resolutions?

How much do you think the facets deviate from a theoretical arc?

Do you have servos?

I don't think the filtering would do anything but make it smoother with slightly smaller diameter.

You might capture the actual trajectory (Destinations) with a C Program to check for any anomaly. I think you did that a few years ago here.