It has been printing nearly flawlessly (it is 2 1/2 yrs old). But, just recently I have had quality issues that I haven't been able to figure out what the cause is. I have attached a photo. [See Below] The part is a simple channel ring. The wall thickness is about 1.5mm I am showing this just as example, it has similar fails on other parts also. I have printed many of these in the past, same file, same settings, no problem. But, recently there is this GAP.
The walls are cylinder - so the printer prints rings to form the walls. Where it starts and stops it is not 'connecting' and leaves a gap.
I have tried replacing the nozzle, that didn't work. It doesn't seem to be the arms, I don't see any abnormal play when the head moves. I have tried slowing the print, that didn't help (but it has always printed at the same speed, no issue before). I played with head temps, nothing seems to change.
Like I said, I have printed many of these without issue before, I don't see anything I've changed. I am now using MatterControl and I don't see a setting that was there in Slicer. In Slicer there was an option to Start Perimeters at Random locations, rather than at the same location each layer. If there is a similar command in MatterControl I haven't found it. BUT, that would only be a band-aid fix, because it wouldn't be addressing what is causing this, since it never had this problem before.
Any help would be appreciated