KW-Jacky

I think you can try increase the retraction distance and restraction speed to eliminate the print string.

The problem has been fixed by enabled part cooling (regular 40% , maximum 60%). I will keep it in my memory, the hot plastic needs cooling time to solidify, the tiny object needs extra cooling time. I will try print with dummy tower to compare the dirrerene .

Dear gr5, Many referene material mentioned , part cooling is not required for the ABS. Hence I have disabled the part-cooling for this print. there is no part cooling from Start to End. I will try enable part cooling (30%) from the layer of this tower start. Many Thanks 🙂

Dear Sir, It is first time to print ABS on my UM2 EXT. I have installed Front Door and Top Cover to keep the ambient/enclosure temperature. Overall print out is acceptable , but the upper part of the print out is deformed . I have to enable the part-cooling / lower the nozzle temperature / speed down the print speed to fix the problem? Nozzle : 215°C Bed : 100°C Layer : 0.2mm Enclosure temperature : ~40°C Slicer Cura : Latest Version Print Speed : 60mm/s Cooling : OFF Regards, Jacky