Simplify3D User Forum

Hi Everyone, I am new to 3D printing and have a FlashForge Creator Pro printer. I am having an issue with the first layer of a PLA print job that is uneven and missing spots (see image, sorry a little blurry but I'm talking about the 2 squares on the left, the right had started its second layer when I took the picture). I've done the bed leveling multiple times and am pretty sure I got it good, and have been printing in ABS with little issues. I'm using mostly standard settings with the exception of First Layer Height, which is at 100%, First Layer Speed at 43% (out of 4200 mm/min)

Not quite sure what to look for on this one.

Thanks for your help.

Have you tried cleaning the bed really good? Sometimes that creates uneven first layers for me, since residue on the bed can easily affect a thin first layer

Looks to me like the first layer is being printed too close to the bed, and you're only getting smashed material out in the low spots (or when extruder pressure builds up enough to push the nozzle up for a bit). I'd recommend bringing your z-offset up a bit. If you need the first layer to be smeared into the bed that badly in order for it to stick, you can ignore it, since it prints fine after that, or you can increase your first layer height.

Learned a valuable lesson recently...when you think your bed is level and right....you're wrong. The only way to be sure is a calibration object. For instance today I thought I had the level correct. So I printed a single layer 20mm cube. My first layer was set at .2mm ...I got .38. The only reason I knew that was I used my calipers. I put -.18 in as my Z adjustment and reprinted...spot on. All that to say the ONLY way you will know if you're at the right height is to use a test object and caliper.