Last few layers random pin hole issue? I'm stumped. Any help would be nice

Hey guys,

Okay, I am stumped. One of my 3D printers just started to produce random pin holes / filament isn't getting layered in random areas, when the print is finished. This is on my Mendel Max 1.5 and Cura is the slicer. I am stumped. I have tried extruder calibration, checking for loose belts, and cleaning the nozzle.

This all just recently started a few days ago. Any type of advice or help would be greatly appreciated.

[drive.google.com]

[drive.google.com]

You can see that the model print fine. There are two fine pin holes at the top of the skull in the picture.

Thanks guys

It's possible your hobbed bolt needs cleaning. If it's only slipping intermittentanly or at the end of a long print it might produce the pinholes you see. After that I would look at my filament if you had a bubble or a bunch of bubbles in the filament that might cause your hotend to sputter.

Thanks Mike

Is there any way you can do a high resolution image of the bubbles you see? I'm trying to analyze what they are and would like to see details down to the line height. please can you upload another image? thanks!

Remember that the lower the infill % the higher number of top layers you need to cover it up.

You don't give any settings but if you have an infill of say 10-20% then you should increase your top layers to say 4 or 8 especially if your machine has issues bridging.

Thanks guys! I will have to check the setting in Cura tmorris9. I usually print at 15-20% but off the top of my head I am not sure what the top layer setting is at, I will look into that. Great tip!

I will also take everyone else's advice too - thanks guys!