We have had quite some serious retraction problems for a couple of months after we received the printer back from maintenance.
At default settings the printer extrudes too less material right after retraction, which results in holes in the top layers, less infill, fragility of thin parts and failures in the outline when starting the layers at the same spot.
I tried different settings and temperatures. Extra length on restart does not solve the problem and results into extreme stringing, what makes our prints unusable. For closed prints it does not matter that much, but we want to print some hollow cases where the printer has to stop and start again within a single layer quite often.
The problems occur with both (dual and single head) extruders and with filaments that print just fine with our other printer.
What could be the cause for this? Which settings do you use? What would you recommend on how to calibrate my printer?
Thanks a lot!