PLA Issues with E3D and Maxstruder (3mm)

[Philip Schmitt]

Hello!  Been awhile since posting (and printing).  I recently had time to upgraded my MM 2.0 (multiple upgrades from way back for the earlier 1.5) with an E3D hot end and maxtruder.  3mm filament, 0.4mm nozzle.  Also using Simplify 3D for my slicer and to run the printer (which works great).  I did need to slow down my print speed a little (1600 mm/min)  from default settings but otherwise when I print with "smooth" PLA it prints great.  Best quality I have seen from my printer.  I had some older white Ultimachine PLA and it worked great at 1800mm/min default for Simplify 3D with MM 2.0.   Also tried some cheaper esun filament from Amazon and that works well too (did need to slow down for this PLA).   The one thing in common is both these PLA filaments have a very smooth finish.

I also have some older PLA from Push and recently tried brand new PLA from IC3D.  These give me all sorts of issues with "bucking" like I am feeding too much filament or have a clog, there are slightly different diameters which I am accounting for in the Simplfy 3D settings (varies from 2.75 to 2.98 depending on roll).  Issues do not seem correlated to filament diameter.   The PLA that does not work well has a rough finish.  When printing I use the "rough" PLA with lots of issues and can't complete a print.  With no changes I can switch back to the "smooth" PLA and it prints fine.  I would think something is setup wrong but with the smooth PLA my prints are as good if not better than they have ever been, though I am slightly under filling. Tested temperatures from 195 to 210 (and even higher) and didn't seem to help.

I totally rebuilt my hotend to make sure it was ok, I printed the updated parts for the E3D hot end (had been using shims to fit original plastic mount) so I think mechanically everything is sound.  

I also updated my Marlin to the latest version on Maker Tool Works website for the original RAMPS board (still using RAMPS) with some minor tweaks for my configuration.

Any thoughts on this?  It's been driving me crazy to figure out.  Right now I plan to just stick to the smooth PLA since it works but I know people have had good experience with Push and IC3D.  

Thanks,

Phil