Issues printing taller objects.

Hey all,

I’m having some issues with taller ABS prints in my lulzbot Taz 4, using an updated version of Slic3r and the fast_ABS_no-support_pt35nzl_pt27layer-11s.ini profile, modified only to add a 3mm brim.

I’ve been seeing some layer splitting, and I wonder if it has something to do with my printer being in my basement, where its a tad drafty.

Attached is the ini, the gcode, an stl file and some images of the issue I’m having.

Thanks for your time,

~~Adam



Cheese Section.gcode (7.2 MB)
Cheese Section.stl (3.54 MB)
fast_ABS_no-support_pt35nzl_pt27layer-11s.ini (3.21 KB)

Printing tall thin objects with ABS is a challenge, which takes skill, know how and a very well dialed in printer to do right, and oftentimes an enclosure is required to get the proper results.

To start with, White filliament in general is a pain in the ass to print. whatever pigment they use to make it white seems to require either a 5 degree hotter than normal or colder than normal temperature, with no rhyme or reason as to why. Generally for better layer adhesion on tall thin ABS items, you are going to want to go hotter. With a Taz 4, you are limited by the buddaschnozzle to how hot you can safely go. 240c which is the minimum to prevent those splits, is about failure temperature of the Buddaschnozzle. You should strongly consider getting a hexagon or similar hotend at this point (a hexagon would let you upgrade to 5 firmware without needing to change anything else, just add a PEI sheet if you haven’t already) . You really want to try it at 250c if you can get there.

If that doesn’t do the trick, try turning on the Skirt option in your Slicer. This will create a 1 filliament wide container surrounding your print and following it up, starting at the edge of the Brim. What that does is act as a wind break and thermal insulator, trapping warm air next to the print and preventing it from splitting. You can manually extrude such a shield into a design when making it as well as needed. If you can, thicken the walls of the part 2-3mm, that will reduce the splitting considerably.

Skirt wastes alot of filliament, so many people opt to just flat out build an enclosure. Since you are in a basement, thats probably going to be your best long term option. There are a couple people selling enclosure kits in the hardware development section of this forum, or you can find several plans for DIY ones in the “all of the mods” thread https://forum.lulzbot.com/t/comprehensive-list-of-taz-modifications/1971/1

Other things that will improve layer adhesion include stiffening the X and Y axes, and removing the bow in the rods. There are various methods available to do that.

Interesting.

I did actually upgrade the nozzle to the taz 5’s version, so I can give the higher temperatures a try.

I wasn’t aware that white filament was an issue, is grey or some other color a bit easier to use?

I will be ordering a PEI sheet soon, and have been looking into getting an enclosure. Hopefully that gets me most of the way there.

Thanks very much for your time.

~~Adam

Gray should print easier as long as it isn’t “silver” which has similar temperature concerns. Black, blue green, they all print pretty easily. Red sometimes has color or adhesion issues. One other note, neutral uncolored abs prints differently than white colored abs.

One other thing I forgot, you can make a temporary enclosure using multiple turkey roasting bags. Tape them up around the gantry, make sure the electronics box is outside to get cool air, leave a filliment path in the top, and see how it goes. Its about 2/3rds as effective as a real enclosure, but it may help.

Good luck, hopefully that helps your adhesion issues!

A quick report in. The temperature increase in the extruder definitely fixed the layer issues. I still have some small issues with the pieces pealing up from the print bed, but its within tolerances at this point.

Thanks very much for your help!