Cura part 3

Sorry for the long delay in posting!  I was working with Cura trying to fix the shifting layers that you saw last post.  I embarked on a new adventure: modifying start and stop Gcode (the language that runs 3d printers).  I realized that the shifting was happening because the head was changing direction very fast and jerking about, so I thought maybe I could slow down the acceleration to get the layer shifting under control.  Acceleration actually corresponds to a Gcode instruction called M201 (set max printing acceleration).  I started with the instruction M201 X25 Y25 Z25 (set max acceleration to 25).  It actually helped! The top image is benchy with M201, and the bottom image is Benchy without M201.  The box that’s behind the cabin of the ship is much less skewed on the top picture than on the bottom picture.

benchyAccelYesBenchyAccelNo

My initial thought was “there’s still some shifting, so why don’t I try and reduce the acceleration more to compensate for that”.  When I reduced the acceleration from 25 to 15 and reprinted, I saw no difference, so I think the acceleration is as tuned as it can be.

The next plan is to adjust the Jerk (how fast the head changes direction).  I just have to research what Gcode instruction controls jerk and play with those settings.  Progress is being made with Cura, so stay tuned!

John (aka The Mad Printer)

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