The Test Boat: Run It, Judge It Honestly
Last lesson was leveling the bed. This one's what you do with a level bed: you print the boat, and then you actually look at it instead of just being relieved it exists.
Everybody who learns 3D printing prints the same little boat. Low poly, curved hull, small enough to run in 15 to 20 minutes. It's become the standard test print for a reason. It's got a flat bottom to check your first layer, curves to check how the printer handles direction changes, and a bow that comes to a point to show you if things are stringing or blobbing where they shouldn't. One object, four or five things to check. Efficient.
I still have my first one. It came out looking like melted candle wax, warped along one edge, the deck kind of sagging in on itself. My bed wasn't level, and I hadn't learned yet that I needed to actually check instead of assume. I kept it on the shelf anyway. Amber calls it "the shipwreck" and she's not wrong. It's a good reminder that the failed print isn't the embarrassing part. Not learning from it is.
Print it
Download any low-poly boat model, there are a bunch of good free ones, load it in your slicer, and run it with your normal settings. Nothing fancy. This isn't the print where you experiment. This is the print where you find out where you actually stand.
Watch the first layer go down. I say this every time and I'll keep saying it: the first layer is the whole print. If it's not sticking clean and even across the bed, stop it right there and go back to leveling. Don't let it run 20 minutes just to confirm what you already saw in the first 90 seconds.
Judge it
Once it's done, pull it off the bed and actually look at it. Here's what I check, in order:
The bottom. Should be smooth, no gaps, no divots. If it's rough or see-through in spots, your first layer was too high or your bed's still not level somewhere.
The hull curves. Should be smooth transitions, not little ridges or stair-steps. Some stair-stepping on a curve is normal, that's just how layers work, but you shouldn't see zigzag wobble.
The bow. This is your stringing test. If you've got thin hairs of plastic between the bow and anywhere else, that's stringing, and it usually means your retraction settings need attention or your temp's a little hot.
Overall shape. Does it look like the boat, or does it look like a boat that's been left in the sun. Warping usually shows up as lifted corners or a twisted deck.
Score yourself honest. Not "eh, good enough," actual honest. This print is diagnostic. Being generous with yourself here just means you carry the same problem into your next ten prints.
Richard's boat
Richard asked me a while back if he could print a phone stand, and I told him sure, but he was doing the whole thing himself. Slicing included. I stood over his shoulder and made him walk through every setting instead of doing it for him. He got to the test print stage and wanted my opinion before he committed to the full stand.
I looked at it for about five seconds. Clean bottom, decent curves, one tiny hair of stringing near the bow that didn't matter. "Not bad," I told him. That was it. He looked a little annoyed I didn't say more, honestly, but that's genuinely all it needed. It was a clean print. There wasn't more to say. He printed the stand after that and it came out fine on the first try, because he'd already worked out his settings on something small and cheap instead of learning the hard way on the real project.
That's the whole point of the test boat. You find your problems on a 20-minute, 10-gram print instead of a 6-hour one.
One opinion here
Level your bed before you blame anything else. I've said it before, I'll keep saying it. Nine times out of ten, when a test boat comes out wrong, it traces back to the bed, not the filament, not the slicer settings, not the printer being defective. Check that first. It's the boring answer but it's usually the right one.
Before next time
Print your own test boat, keep it, and write down on a sticky note or in your phone what you saw wrong with it, even if it's small. Bring it to class. We're going to start fixing these one at a time starting next lesson, and it helps if you already know what you're fixing.