Unresolved Ideas on what is causing this print abnormality?

I'm running with an R1+ (mostly stock, many repairs) driven by Simplify3D. Printing in ABS, closed heated chamber, hairspray on bed with glue on corner areas to motivate adhesion.

I usually print small parts, but recently needed to print a larger part and ran into the back right corner lifting from the bed no matter what magic I tried (Hairspray, glue, increased bed temp, skirt):



Flipping the part over to inspect said corner I noticed the spacing between lines seems to increase and print quality especially falls apart on the disk in the corner:





You can see the transition from decent quality to not as we move along Y here:



Other corners printed/adhered fine as shown here:



Thoughts? My only thought at the moment is a hardware issue that accumulates as I move along Y. Maybe the belt.

Thank you for your time an help.

Jeff

 

I have problems with prints lifting at the corners that I've attributed to the fact that the bed heating is uneven, as revealed by a remote temperature sensor (the sort that you point at an object to find its temperature without physical contact). This doesn't look like that, though; this looks like the bed level is off -- the bed is a little lower (or the G29 thinks it's higher than it is) in that corner, resulting in the first layer being too high in that corner.

Are you doing a G29 probe at the start of your print? Is this outside the area where your G29 probe is happening? If so, you might look into increasing the probe area, although IIRC that requires recompiling Marlin. You should also be sure that the glass is clean (aside from your adhesion agents) at the start of each print; if the printer is probing a spot and hitting a blob of plastic from a previous probe or print, then the bed reading will be off. Depending on how you're printing and what sort of hardware you have, you may be able to adjust baby-stepping on the first layer to lower the head just a little in that corner. After the first layer, it shouldn't matter (although I hear that ABS is prone to separation, so it might in ABS if you need to make a big baby-stepping adjustment).

 

Thanks for the fast response guys!

I am doing a G29 probe and cleaned the print area before printing. I will check where the probe happens though to make sure its in the print zone (Thanks!). Now that you guys mentioned it I can see it being an uneven heated bed issue. Two followup questions:

(1) Will PLA behave on an uneven heated bed?

I use ABS and have learned to deal with all it's "warts". With this larger series of prints I'm thinking of using PLA since it supposedly will stick better, doesn't need skirts, and should closely match the CAD design without "ooze/shrink" compensation like ABS requires. Plan is to:

• Use Prusament PLA since it is dimensionally accurate, high quality
• Add a new nozzle (it's due and why not)
• Use hairspray on heated bed
• Setup an oiler

(2) Will a PEI sheet help circumvent the uneven heated bed ABS issue?

I will definitely order some of the Wolfbite and try it out (thank you), but am curious about PEI sheets (and similar) than can be reused on the bed. The thought/hope is that a sheet will have the extra holding power to compensate for the uneven heat issue so I can have the option to print large format ABS on a reusable surface in the future.

Thank you for the help.

Jeff