Well bowden printers generally have to retract a lot more than direct drive. This means they generally have more trouble printing tiny features, because all of those large retracts can create issues like this.
You can sometimes work around it by retracting less or increasing your "extra restart distance" so that you get more plastic flowing at the beginning of the island.
You have very accurately stacked layers there - typical of a Kossel. Great machines.
I'd agree this is definitely a retraction problem. It can take a little while to get the retraction settings tweaked.
You need adequate retraction to avoid stringing, but no more than necessary because it will slow you down and can cause restart problems.
If your extruder is working properly (not slipping), and you are using good quality filament then you really shouldn't need any extra restart distance. Higher retraction speeds and faster non-printing moves usually help you get more accurate retraction restarts.
As far as settings go, here are a few that you might try changing:
Under the Advanced tab, don't force retraction between layers.
Under the Extruder tab, get rid of the negative restart distance. Set to zero.
Retraction distance of 6mm is a good starting point - if you are still getting a bit of stringing, increase slightly.
Retraction Vertical lift can be set to zero (you've already turned it off in the Advanced tab suggested above)
Increase the retraction speed. Double or triple it. I run 100mm/s and I know a lot of people run even faster.
And finally, your non-printing moves can be sped up quite a bit to give the hotend less time to ooze. In the "Other" tab
your X/Y speed is set to 116.7mm/s. A Kossel can go a LOT faster than that. I run 160mm/s and that is considered by most to be slow.
No need to limit Z axis movement speeds so much either. I typically run 80mm/s. Whatever you are comfortable with.
KDan wrote:
As far as settings go, here are a few that you might try changing:
Under the Advanced tab, don't force retraction between layers.
Under the Extruder tab, get rid of the negative restart distance. Set to zero.
Retraction distance of 6mm is a good starting point - if you are still getting a bit of stringing, increase slightly.
Retraction Vertical lift can be set to zero (you've already turned it off in the Advanced tab suggested above)
Increase the retraction speed. Double or triple it. I run 100mm/s and I know a lot of people run even faster.
And finally, your non-printing moves can be sped up quite a bit to give the hotend less time to ooze. In the "Other" tab
your X/Y speed is set to 116.7mm/s. A Kossel can go a LOT faster than that. I run 160mm/s and that is considered by most to be slow.
No need to limit Z axis movement speeds so much either. I typically run 80mm/s. Whatever you are comfortable with.
Thanks!
I've changed settings as You suggested. Raised temp to 230 because of some problems with putting a solid line by the extruder.
