Everyone’s first print goes wrong in roughly the same handful of ways. Here is what we wish someone had told us before we burned through a spool learning it ourselves.
Bed leveling is not optional
Something like seventy percent of failed prints trace back to a bad first layer, and a bad first layer almost always traces back to an unlevel bed. If one corner of your build plate sits even slightly higher or lower than the rest, you get lifting corners, patchy adhesion, and prints that peel off halfway through. Level the bed before every print that matters, not just the first time you set the printer up.
Slow down the first layer
Printing the first layer too fast is one of the most common beginner mistakes, and it is one of the easiest to fix. Drop your first layer speed in the slicer, even if the rest of the print runs at normal speed. That one layer decides whether everything above it holds together or fails halfway through.
Clean the bed like you mean it
Fingerprints on the build surface are invisible until your print will not stick to exactly that spot. Wipe the bed down with isopropyl alcohol before anything you actually care about, and try not to touch the print surface with bare hands in between.
Respect the 45 degree rule
Overhangs print fine up to about 45 degrees from vertical. Past that, you are asking the printer to extrude plastic into thin air, and it sags, strings, or just fails outright. Either design around it, orient the part differently, or add supports. Fighting physics with slicer settings alone only gets you so far.
Start with PLA, and mean it
PLA gets called the training wheels of the filament world for good reason. It prints at lower temperatures, resists warping better than the engineering filaments, and forgives more of your early mistakes while you are still learning what “retraction” and “cooling” actually do to a print. Move up to PETG or ABS once PLA stops surprising you.
What we would tell ourselves on day one
Do not buy the cheapest filament you can find and expect quality results. Do not skip maintenance because the printer “seems fine.” Do not pick an ambitious model with thin overhangs and moving parts as your first print. Print a calibration cube, then a few boring, blocky test objects, and build up from there. The exciting prints get a lot more exciting once the boring ones actually work.
Talk shop with us
More print lab write-ups live under the 3D printing project. Got a print that went sideways in a way we did not cover here? Post it on The Bench, failures welcome.