weak bed adhesion - Taz 4


I have switched to PEI sheet in my Taz and got drastically better results however I think that my print has some adhesion problems.
I have attached the pictures. From one side (where the fan was blowing) the print lifted up a little bit (I can insert a A4 paper underneath it).
Also bottom part of the print doesn’t look that smooth to me, can it be something to do with PEI sheet or should my hot tip should be somehow closer to the surface?
Would it also help if I turn off the fan too?

thanks a lot

ps: Sorry, I seem to open this thread under General - Hardware, whereas it should have been in Taz section. Can the admin please move it to Taz section.

What type of filament is that?

Lower the Z-endstop by a quarter to half a turn. That should help increase the “squash” which promotes adhesion to PEI. An alternative is to use the Z-offset settings in your preferred slicer. Set a -.1 to -.2mm.

More than likely your bed is not perfectly level, this is a critical step for PEI to work properly.

If that is ABS then the bottom looks good otherwise but you don’t want the material fan on at all.

If it’s PLA then the Z axis is a tiny bit high and turn the fan down say 20% from what it is. And make sure the fan is off for the first 1-2 layers.

With PEI you want ABS to just barely kiss the surface (if you smash it in like other materials then it sticks way too hard).
But if you print with PLA then you want to smash the material down pretty good.

Hello folks,

Thanks a lot for the answers. The material is ABS. I will try them on thursday when I have access to the Taz 4.
One thing though, after I posted my question, I printed another thing and set the fan speed lower manually. The outcome was better.

I’ll report back again


Sorry for my late reply. I had made more tries, with smaller prints I have better outcomes now but with larger prints my problems still go on

my calibration gcode output is quite fine, with a very slight deterioration to the right side of my printbed however I don’t think it should cause this much of bending.

Should I make a acrylic protection around my printer? Also should I use a little bit of ABS juice?

Also I have ordered ngen filament. They say that it has better toleration to heat and warping.

if you have any recommendations, I would be happy to follow them.

If you want to print ABS reliably then an enclosure is a must.

What is your bed temp?
Are the extruder fans running? Try turning them off.
Try printing a brim (there’s a setting in cura). The brim adds more surface to the first layer giving better adhesion. It breaks off after printing.

Post a pic of the bottom of the object. The infill pattern can be used to analyze the nozzle to bed gap…

Give your z-endstop a quarter turn clockwise, or use the Z-offset setting in your slicer to lower by setting the value to -.1 to -.2.

Hello folks,

Thanks a lot for your answers. They were all very helpful.

I tried the “brim” and it helped a lot.
I also tweaked the calibration untill I have a satisfactory taz_calibration print.
I didn’t have an enclosure but I tried shutting down the windows and it seemed to help too. However I can’t do this all the time (this is where I work and I will poison myself :confused: )

Therefore I switched to ngen material and the warping has gone away. Below I post the pictures.

I have also attached the profile (and also the stl file) that I am using. I am trying to tweak it to get better performances.

The current problem I have is that, the hole dimension in the STL file and the 3D print is not the same. I have got a difference of 0.7mm

Can you please also guide me about what I should do to solve this? Currently I am trying to increase the hole dimension in the STL file so that the print itself has the hole dimension that I need but this is just a hack.

thanks so much for your help once more.
Sensor Disk.stl (67 KB)
nGen_high-quality_TAZ_single-extruder_0.35noz_cura.ini (11.3 KB)

Could be a sign of overextrusion. Try adjusting flow rate to 95 - 97% and check for dimensional accuracy.

Best to create your own dimensional accuracy test. Make a solid cylinder with a known OD, then a hollow cylinder with a +.1 - .2 ID. Should fit pretty tightly if the extrusion rate is well calibrated.

The proper fix for this to the esteps of your extruder. Claibration steps are here. Basically, mark the filament 150mm above the idler, extruder 100mm, measure the mark to the top of the idler… you should get a measurement of 50mm.