Had an issue with a large ABS print on the Taz5 where the corners would lift up even after adding brims to the edge of the plate and a thicker base layer so I decided to try some glue stick. Bad idea, terrible (even worse adhesion), so I cleaned it off with water and iso-alcohol.
First test print after getting rid of the glue stick - minimal adhesion, so little in fact that even with a brim I could easily remove the print even when the bed is at operating temps (110C). It quite literally slide off with the tiniest of persuasion. Tried cleaning the bed again (no it was not my Z-height), no go again. Tried Mr. Clean eraser, no dice. About to sand it with some 2000 grit wet/dry.
Any other things I could try? The printer has literally only been used for a month. I don’t want to have to resort to using ABS juice because the PEI wasn’t like this before the glue stick.
The PEI sheets are user replaceable, worst case. I’ve done it twice now on my mini. Not a big deal. I sanded mine with 800 grit EXTREMELY lightly and things stuck very well. I must stress the very EXTREMELY here.
Check that your PEI sheet doesn’t have large bubbles in it. Also check the actual temperature of the bed with an infrared point and shoot thermometer to make sure you don’t have a failing thermistor or heated bed that is heating much lower than it thinks it is. Also if you can post an image of the bottom of the part you were trying so we can check the adhesion
First one is from before the gluestick shenanigans, the second is the part that failed (corners lifted). Third is after cleaning off the gluestick (corners failed again) and fourth is with a 2mm base layer.
The last attempt seems like it worked (no lifting/warping!) but it wasn’t stuck to the bed and the center looks like it was about to cup. Will do the 800 grit (lightly!).
Yeah, you are getting good adhesion initialy followed by lifting. This is either a bed heat issue, or you have some oil residue left on the bed, which the light sanding will also fix.
I had some adhesion problems on my mini. Lulzbot told me to use isopropyl alcohol and a folded cotton cloth (I used an old terrycloth washcloth) to vigorously clean the PEI. That solved my problems.
I’ve had an issue with larger prints that have a smaller footprint than the widest part and found that reducing the bed temp to 70C from 110C after a Z height of 2cm-ish helps immensely with the elephant’s foot (eliminated it actually) - before it’d squish the lower layers down so much that I get a solid base.
Generally speaking the cooling fan is bad for ABS, it promotes delamination. But some models will need it (for serious overhangs) and then it’s just finding the right amount.
If you’re getting good results then carry on with what you’re doing I’d say. It’s possibly a factor behind bad adhesion though, I couldn’t tell you for definite.
