I can say that I satisfied print quality in general.
But, there are still few issues remained I want to resolve.
As you can see in the photo, there is a line of blob at the surface. I noticed it caused by layer change. Is this something I can fix by adjust options in slicer? or something related with acceleration?
If I change seam position in slic3r from aligned to random, those blobs will disappear, but many pimps are show all over the surface which I can not bear to see.
Any advise would be appreciated.
Slicer does have a randomize feature for layer change. Increasing retraction, for the layer changes, should reduce this effect. It may not be possible to eliminate it though.
It’s somewhat counterintuitive, but if you’re using a bowden extruder you may have luck entirely disabling retraction on layer change. That’s what finally fixed it for me.
I think it’s because the head pauses to retract, and then to change layer height, and it’s slightly oozing as it pauses to retract. Without that extra waiting time, the blobs get much smaller or disappear entirely.
I have had the same problem as you in one piece similar to this one. I thought that it was a problem with my printer motors. Thanks for publishing. My printer is Witbox (BQ).
@Brook_Drumm random option produce lots of pimps (small bubble) on the point of layer change, and currently my retraction is 4mm / 40mm sec, I tried 4.5 / 60 but no success.
@Stephen_Baird I use bowden and I tried 1mm retraction but never thought disabling it. I’ll try
Ooh, a problem I recognise and am at a loss to cure. I too will try out your tip, @Stephen_Baird . Thanks!
@Stephen_Baird I did quick test with same file, and same result. 
Judging by the test result (4mm retraction & 0mm retraction), it seems retraction has nothing to with this issue.
@DongWon_Han_DWONH it might be the temperature you’re printing at. If it’s in pla, don’t use 220, even with a fan right on the nozzle, take it to 213-215, max. 5-7° make a huge difference and the layers will still adhere properly
Use Cura to slice instead
And slow down print speed
Try using kisslicer instead see if it takes them away
I’ll try tuning retraction speed first, then slow down perimeter speed. If all fail, I’ll try Cura this time.
@Adrian_Ciubotariu It is ABS, no cooling. currently 225 degree. I’ll do temperature drop too. Thanks.
@DongWon_Han_DWONH it sounds silly honestly. Check my page though, I have a post that shows slicing of a model with Slic3r and then with Cura. BIG difference. No setting changes just hitting slice. Will give you an idea of Slic3r’s generated Gcode compared to Cura’s.
@DongWon_Han_DWONH I would like to add though, besides the small details your trying to fix. You’ve got some really good quality there.
@David_Wille Thank you!! But I’m afraid that I can not find the page you mentioned. Could you give me the link?
Update.
- with Slic3r
- Changing retraction speed -> no difference
- Slow down perimeter speed -> I could not see the difference
- with Cura.
- I setup Cura and did quick test
- Show noticeable improvement, but little line could be seen, much better than slic3r though.
Maybe I might dig into acceleration and zerk numbers?
@David_Wille This post could not be found.