Newbie: Print issues Lulzbot mini

Hello everyone,

I am new to 3D printing and have been working to introduce 3D Printing to my high school class. We’ve had a luzlbot mini for almost a year and have had no issues. We have been printing nametags (images included, they are about 100mm x 70mm x 8mm made in TinkerCAD, in the one image you can see one of the older printed name tags and how they should look) and have not had any issues, until about a week ago. The prints started having issues (I have included some images). Basically, the print starts and then either has the not completely melting issue, or the first layers print and then nothing. The one fan is on all the time and the second fan does come on as it goes through the print. I am able to set the temperature and extrude, and the filament comes out in a nice straight string (sorry if not using the proper terminology). We use PLA filament (bought from lulzbot). I have changed the filament and still having issues. I do notice with the prints that start to print and then do not finish, when I take the filament out, there is sometimes a gouge in the filament and some fine shavings around the area. I did try printing a small little christmas type hook, and it seemed to print ok.

Any places to look for troubleshooting tips would be wonderful as we are all complete newbies.


There could be a number of things going on here. PLA is infamous for being susceptible to “heat creep” which is cause by insufficient cooling of heat brake where the filament can soften too much and cause jams and the stripping or chewing of the filament by the hobb bolt. Does your Mini have the small 20mm fan on the front? If so, that could be the problem. A larger 40mm fan will keep the filament cooler before it enters the nozzle and eliminate the jamming. Here is a fan shroud on thingiverse from IT-Works which can be printed out and they sell the 40mm fan to replace the small one.

Of course there may be other problems as well. Here is an invaluable resource to help find the causes and solutions for filament problems: