TAZ5 Mimicking Printing

About a month ago I had purchased a Taz 5 and at first it was printing fine, but now it appears as though it is fake printing some layers. The print will start off okay, but a few layers in the tip will stop extruding and it will continue to operate normally as though it is actually extruding the filament. A few seconds latter it will begin extruding again, but since it missed a layer in a certain spot the filament will not lay. I have tested this with different models to make sure it was not the model’s fault, but it keeps happening no mater what model I use. I am very new to using a 3D printer so any suggestions are welcome. I use a Taz Lulzbot 5, Sli3er and Cura. Thank you.

There are a couple of things that could cause this. Usually when the extruder stops extruding, it grinds a hole in the filiment, and it won’t restart without intervention. I think to mark the filiment as it goes in to the extruder with a magic marker so I can see that its still feeding the filiment. Check the fan that blows on the hexagon part of the hot end. This is a very necessary part of the hot end, and causes all kinds of issues if heat is allowed to melt the plastic way up in the hexagon part. Maybe tighten the thumb screws a couple of turns to get more force on the feeder. About 10mm of space between the extruder body and bottom of the screw is about right. Try slowing down the printing speed and see if that has any effect. Make sure the filiment can feed smoothly from the spool. Ive had many prints ruined because of a tangle at the spool. If you can identify conditions where extruding stops that would help diagnose the issue.

Check that the small setcrew on the extruder motor small gear is still down and tight. If it comes loose, the gear can slip on the shaft, so it appears it is extrudeing correctly, but is onnly actually rotating a fraction of what it should be. Also check the spring tension of the idler arm latch springs. You should have about 8mm between the inside of each washer on either side of the spring. Jamming due to overextrusion is another possibility.