Poor surface finish

[jens55]

@mrehorstdmd, the speed limiting happened because of layer time. Once that was reduced from 3 sec to 1 sec, the speed was back up to what it was set to in Cura.
In the past I had set jerk to 25 but as it turns out, I had turned off jerk control for some reason or another.

[infiniteloop]

@jens55 said in Poor surface finish:

Apparently as of RRF 31. speed factor does not affect extrusion speed.

I'm still at 3.3b4, but up to that version, I can assure that extrusion follows the speed factor precisely. Apparently, with your apparatus, other factors play a role

[jens55]

@infiniteloop, well that is quite possible since making assumptions and jumping to conclusions is one of my fav past-times
It just seemed to fit - proper extrusion at the original speed, increase 'speed factor' and see under extrusion. While it is possible that I was pushing the extruder too much, in this case I was going relatively slow and would not have thought that I was anywhere near the hot end limit.

[rjenkinsgb]

@jens55 From the way the defects occur at similar locations in different consecutive layers, I suspect something mechanically sticking - eg a bit of grit in a bearing or a dry bearing.

That could explain the blob or melting effect, if the nozzle momentarily pauses them jumps past that spot once the drive system has wound up enough??

[dc42]

@jens55 said in Poor surface finish:

Apparently as of RRF 31. speed factor does not affect extrusion speed. I am not sure why this was changed from the earlier versions of RRF where speed factor modified all speed settings including extruder speed.

Speed factor is not applied to extruder-only moves, i.e. retraction, reprime, filament loading and unloading.

[jens55]

@dc42, thanks for the clarification !

[mrehorstdmd]

@rjenkinsgb I had an extruder motor cable failure several years ago when I used a too small bend radius in a drag chain. It would cause the extruder to cut out momentarily at specific XY locations in the prints. It took a while to figure out what was happening. The wires had fractured inside their own insulation, the result of being bent too many times.