Issues getting it right

Hello. Total new person here to the 3d printing arena. I’m trying to make a case for a put it yourself together oscilloscope. I’m using inland 2.88 PLA. I dont know whats going on here but its pretty annoying. I thought it was the build platform heat abeing set too high at 60c so i lowered it to 45c. maybe its a setting with the cura program? I’m using a Lulzbot mini with an lcd. the corners are off a little haha!

Must be that time of year, I’m having PLA prints lift up off the bed also. Same PLA I’ve used for past prints that didn’t lift off.

Warmer is better (to a point). Set your bed temp to 60 or 65C. Make sure your bed is clean, no oils on it (even oils from your fingers). Wipe down with isopropyl alcohol. If the bed is a bit used and aged you can also sand it with 1,000 grit or finer sandpaper. I wet sand with the isopropyl alchol.

How’s your first layer? What’s your offset? Too high and it won’t stick, too low and it won’t flow. May need to experiment. Maybe try -1.540 to start. Make your first layer thicker than your other layers. .4mm for a .5mm nozzle. Print with the highest temperature the filament can withstand 230C, 240C. Turn off your cooling fan if you don’t have any bridges or need for supports. If you do you can lower the cooling fan’s percentage. Make sure there’s no drafts near the printer.

PLA likes to warp away from the bed any time one section is cooling faster than the others. The heated bed helps mitigate this but is less useful the further away you get from the bed.

The solution is going to involve finding the right spot in a confluence of factors including : hotend temp, bed temp, the temp of the room you’re in, airflow around the machine, and the shape of the object you’re printing. Larger, more solid objects often have curling issues, especially at the corners. You can mitigate some of this with a brim or raft around the object, or try using the experimental “draft shield” setting which builds a physical wall around the object. If that’s the glass bed you can also try a little glue stick to help the PLA adhere better.

In general this is a really good resource for troubleshooting prints and figuring out why something is wonky: Print Quality Guide

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Something to check as well is your z-offset. If set too high, you may get parts that lift off the bed.

Here is a good visual representation of what to aim for with regards to a z-offset.

If your offset is set to where it should be, you could scuff up the PEI surface with a scuff pad and some isopropyl alcohol.
This process is very easy using the guide below.

We do this in our print farm when our printers need a bit of TLC.