New member experiencing layer adhesion problems

Greetings all.

New TAZ 6 owner here. I purchased one used last weekend. I’m a mechanical engineer, and have experience in fabrication, machining and modeling, but am new to 3D printing.

Here’s my problem:

I tired printing something with ColorFabb PLA/PHA last night. I used default settings (220 C nozzle, and 60 C bed, if I remember correctly). However, it’s coming out very brittle, and my layers aren’t adhering to each other. I had to stop the print half way through because one of my supports snapped, and after I removed the print from the bed, I realized I could quite easily break most of the layers apart by hand.

First question, could this be due to old material? This filament is probably 9+ months old. However, it had never been opened before 2 days ago, when I removed it from it’s vacuum sealed bag.

Second question, what settings could I tweak to help getting better layer adhesion?

Any help or tips would be appreciated, on this topic, or really anything. I’m learning as much as I can, as quickly as possible, but there’s a lot of variables to all this.

I’d slow the print speed a bit and increase the bed heat to 70.

Did you print a skirt around your part? If so, take a pair of calipers and measure the thickness of the skirt and let us know what it is. Many times parts aren’t sticking because your Z-height is too high. Start with that.

I believe PLA/PHA has a higher glass transition temperature than PLA so you’ll need a higher bed temp. Ideally you want your bed tempt to be slightly higher than the glass transition temperature of whatever material you’re using. That’s why ABS bed temps are 105C to 110C. It’s glass transition temperature is 100C.

If we determine your z height is dead on and increasing your bed temp doesn’t do it, then the next thing would be to clean the bed with IPA.

If that doesn’t do it, take a piece of 1500 grit wet sandpaper and lightly sand your PEI sheet.


Thanks for the tips.

I seem to have solved the issue by upping the bed temp to 70, nozzle temp to 240, and lowing the layer height to .15 - .25 (it was at .5 before).

Now I’m dealing with the print sticking too much to the PEI bed. Even without any glue, it’s incredibly difficult to break the print free without damaging it. It’s certainly a better problem than my last one, but I’ll take any additional recommendations people have. =]

  1. Change your initial layer width from 125% to 100%

  2. Measure the thickness of your skirt on your next part with calipers. If your nozzle is too close to the bed, this will also cause over-adhesion.