new gaps in layers

there have been tinny gaps in the bottom and top layers of my prints as well as the infill with it being very stringy and it seams like it is getting worse as time passes and I need to know how to fix my bad layers.




My first guesses are underextrusion, filament diameter incorrect, and Z-Offset too high.

Just to be sure it’s not a setting changed, download the profiles from lulzbot and try in Cura to make a test print. In the machine settings screen, make sure Z-offset is 0. If that works, you have somewhere to start comparing settings.

Measure the filament and make sure that the diameter is entered in the slicer accurately.

Make sure the drive gears are not slipping on the extruder, and that the idler tension is correct. Maybe try the e-steps calibration.

You don’t say which machine you have, but Minis might have a broken idler arm. There was a service bulletin about it a while back, with a link to a fixed STL you can print. I believe Lulzbot will send you one as well. I don’t know if this issue exists on the Taz line…

Found the link… https://www.lulzbot.com/sites/default/files/extruder_idler_service_bulletin.pdf

I changed the e steps and that seemed to work but I was not aware that could change over time. I am currently using a taz 5 with a flexystruder tool head and I am printing cheetah flex. I was wondering if there was an easy method to calibrating estep because I basically just guessed based off of what my other printers had for theres.

estep calibration: https://ohai.lulzbot.com/project/extruder_calibration/calibration/

The other thing to check is your filament diameter. That’s really the only thing that would change during a print as it’s often not totally consistent through the roll. Take your calipers and take measurements at several points spread out and do an average, and then enter that into cura/whatever you’re using.

I know what the problem is I have two printers and I set them both at 227 one was printing fine the other was under extruding and so I used a heat sensor and I am seeing one printing at a higher temp. the under extruding printer is printing at around 220 and the other is at 245 why is this and can I fix it