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g2core - The Next Generation
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CCW arc goes wild #76

Closed drsubs closed 8 years ago

drsubs commented 9 years ago

G03 X27.811731 Y4.565054 I0.01976 J-30.977549 this gcode makes my machine go into a large arc(CCW).

It was produced by CamBam

drsubs commented 9 years ago

additional info: [fb] firmware build 82.10 [fv] firmware version 0.98 [cv] configuration version 7.00 [hp] hardware platform 3.00 [hv] hardware version 0.00 [id] TinyG ID 0213-2325-8333 chillipebber does not show any thing wrong, but when the arc is finished the tool comes rushing in from off screen.

lllars commented 9 years ago

That line of gcode should make a large radius arc. See a description of G3 here. The I and J terms are a vector from the current position to the arc's center. So your radius is ~31 units (inches or mm?).

Does that help? If not, please post more/all of your gcode file.

lllars commented 9 years ago

I should clarify that what I wrote above is true for G91.1 mode (where the arc center is specified in relative units). If you are in G90.1 mode, the arc center is specified in absolute units.

lllars commented 9 years ago

just figured out that tinyg2 doesn't support G90.1 mode. It is always in G91.1 mode.

There seems to be a bug wherein trying to specify G90.1 mode results in G90 mode. G91.1 is similar, it results in G91 mode.

drsubs commented 9 years ago

No this is an bug here is the g file: https://dl.dropboxusercontent.com/u/2787926/hejtek.ngc and a screen shot of chillipeppr and the milled result the offending line is line #848 screen: screen-cp foto: 20150412_210224

aldenhart commented 9 years ago

I was able to reproduce the error you showed above. It seems the arc off the bottom-right stroke of the K wants to draw a complete 360 degree circle. It's interesting to note that the start and end points of line 848 are almost the same. I suspect that are being considered the same (erroneously), and this very small arc is being interpreted as a full circle. I am using the latest edge push - build 083.07. I'll track this down. Thanks for the detailed file to reproduce this.

drsubs commented 9 years ago

Thnx, I´ll move on to 083.08

aldenhart commented 9 years ago

Hi. I'm not quite ready to close this. I understand the root cause, but I don't yet have a solution out there. I'll close this once I've got a solution out to edge - hopefully in the next few days. 083.08 is not ready for use - it's just my tests.