Leveling the Bed Before You Blame Anything Else
New module. We've done filament, we've done the slicer, we've done first layers. Now we're actually printing things, and that means we're going to hit problems. Before you email me about a failed print, or worse, before you decide the machine's junk and it's going back in the box, level the bed. I mean it. Do this first.
I'd put money on it: nine out of ten first-print problems are the bed. Not the filament. Not the slicer settings. Not some setting buried three menus deep that a forum told you to change. The bed.
Why this matters more than people think
Your nozzle has to lay down that first layer at a consistent height across the whole plate. If one corner of the bed is a hair closer to the nozzle than the other, that corner gets squished too thin or the nozzle straight up gouges into it. The opposite corner, too far away, and the plastic doesn't stick at all. It just drags around not attaching to anything.
You end up with a print that's stuck rock solid on one side and peeling up like a bad decal on the other. Or one that never sticks anywhere and turns into a hockey puck stuck to your nozzle. Either way, it's not the slicer's fault. It's geometry.
How to actually do it
Most beginner printers still use manual or assisted leveling, so here's the routine:
- Heat the bed and nozzle to printing temp first. Metal expands when it's hot. Leveling cold and printing hot gives you slightly different numbers. Not huge, but enough to matter.
- Home the printer so it knows where zero is.
- Move to each corner (most printers have a menu for this, or you do it manually with the leveling screws) and use the paper test. Slide a piece of regular printer paper between the nozzle and the bed. You want slight drag, not none, not the nozzle plowing through it.
- Adjust the screw under that corner until the drag feels the same as the other corners.
- Check the center too. Beds warp. A corner-perfect bed with a bulging middle will still fail.
- Recheck all four corners after adjusting the last one. Tightening one screw shifts the others slightly. Go around twice minimum.
Give this the full 15 minutes it takes. Don't rush it because you want to see the print go. That's exactly the impatience that gets people a shipwreck. I've still got mine on the shelf, first thing I ever printed, the standard little boat everybody starts with. Looks like it melted in a candle. Bed wasn't level. Amber calls it "the shipwreck." I keep it there on purpose.
The corner most people forget
Small, detailed prints are the ones that punish a bad level the hardest, because there's less surface area holding the whole thing down. Olivia wanted a bracelet printed from a model she found online, small chain links, fine detail, the kind of thing that lives or dies on that first layer being exactly right. Took me four tries. Every fail was stringing and lifting in the fine spots, and every fix traced back to the bed not being dialed in as tight as I thought it was. I acted put out about it at the time. Then I printed her a second one in a different color she hadn't even asked for, because once I had it dialed in, why not.
That's the thing about leveling. It's not a one-and-done setup step you do out of the box and forget. Check it every few prints, especially if you've moved the printer, bumped the bed, or swapped nozzles.
A real caution here
Your nozzle will be hot enough to burn you during this whole process, usually 190-220°C for PLA. Do the paper test with the paper, not your finger, and keep your hand clear of the nozzle path when it's homing or moving. It moves fast and it doesn't know your hand is there.
One more thing before you touch anything else
Slow down your first layer, which we already covered, and level your bed, which is this lesson. Do both of those before you start adjusting temperature, retraction, speed, or anything else in the slicer. People chase settings for hours trying to fix a problem that a $0 bed level would've solved in 15 minutes. I've seen it. I've done it. Save yourself the Saturday.
Before next time: level your bed using the paper test on all four corners plus the center, then print the same small test file twice in a row without touching any slicer settings in between. Bring both results to class, good or bad.