Unresolved PLA adhesion problem

So recently just out of nowhere my prints stopped sticking to the bed. I'm using an Aqua Net hair spray and I didn't have problem with it previously. I've gone through more that a half of the bottle of it and recently parts of the print don't stick. Yesterday I printed a large print 23cm x 13cm area (all flat on the glass) large part of it sticked to the glass but some of it didn't and the not adhered part started lifting and that side is not straight but curved slightly. After removing the print next morning I wiped my finger over the printbed and it was a little greasy (not only under the print but around it too). Is it possible that the Aqua net spray contains some greasy product which makes the glass oily?


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I doubt if anything dripped, I run an oiler but it wasn't too moist. Also the printbed was pristine clean and dry before I applied the hairspray. I thought that if there was any settlement of the substance the greasier part would float on the top (likely) and when it runs low it would spray the greasier substance. But I'm using the hairspray almost everyday for the prints so it shouldn't happen. What are you using for the adhesion? Did you ever run dry the aqua net bottle?


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I think waldo's theory is a good one. If you're printing something larger than the heated pad I suggest as low of a heated bed temp as possible. 30C would be my advice

 

I'll try dropping the heat down a bit. But why would the rest of the platform feel greasy after cleaning the platform completely and just applying the Aquanet? Also after replacing my X carriage the nozzle tip raised by a fraction of an inch. How do I change the Z offset in the firmware? Which line is it?


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The nozzle position is not relevant to the Z offset.

Clean your platform with isopropyl alcohol

 

But isn't the Z offset a height adjustment?


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I understand, but for whatever reason I noticed a slight under-extrusion on the first layer which previously wasn't a problem. I also flashed the firmware right before that to speed up the calibration process and to calibrate the extrusion.
EDIT: rather than an under-extrusion it's gaps between the lines of PLA (as if the nozzle was too high above the glass)


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Yeah the Z offset is a measure of the distance from when the nozzle touches the bed causing the carriage to stop moving, then the lowering of the switches till they untrigger. The nozzle could be 10mm different from where it currently is and would still have the same Z offset

 

I totally see where you guys are going with it however, I'm suspecting that bad adhesion could be caused by the fact that the nozzle is slightly higher in the air and instead of laying the plastic flat on the bed, it prints it so it just touches the bed and it lays a thin string which appears to be a nice bead but it won't stick. I cleaned the bed with alcohol and tried again, there was no more grease on it whatsoever but still some parts of the first layer didn't stick.


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You need to reduce your Z offset for that

 

alright! the Z offset problem solved! I went for a -0.85
Now I decided to print a test prints and all fine detail is not as good as I would expect it. Very narrow gaps are totally filled and extremely thin detail is not being printed at all.

 

Black filament is very hard for taking pictures of it. This piece is printed after extruder calibration with a layer height of 0.2mm an temperatures 200nozzle/50bed


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Do you mean the E steps/mm ?


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