Hi all Trying to get my DIY cnc running on Grbl & Chillipeppr,

CAD & CAM Tool Chain ChiliPeppr
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Hi all
Trying to get my DIY cnc running on Grbl & Chillipeppr, everything looks great except when the mill tries to perform arcs (G02 or G03) then things go wrong!

The Draw a circle demo Gcode (in the Wiki) produces a weird almost “s” shape!

Any ideas?

  • i loaded the Grbl via the “library” method, Grbl 0.9j

p.s. I am pretty sure this is NOT a chiliPeppr issue - as drawing an Arc via the Arduino Serial monitor produces the same error.
sorry for crashing the group, but you guys are my only hope! (insert Star wars theme music here!)

Thanks

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I’ve usually seen it as G2 and G3, without the zero. Not sure if that makes a difference. Check your belts. And we’d really need to see some pics or video of the issue to provide any further advice.

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Are you sure the X and y axis are both moving correctly in terms of positive and negative directions?

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Thank you both. @raykholo ​ the mill uses ball screws. And after battling for ever I finally realised that one cannot add a photo in a reply!
@Steve_Welsh ​ yes the home and off set work 100% in fact all (that I have tested) g codes work as expected just arcs are weird.

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This was the circle demo g code from the grbl wiki

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Well I do like ball screws… My advice try running in mid air and see if the issue persists, and try turning the feedrate way down.
Finally, try a different gcode file, perhaps one you make yourself.