Before you print: setup, maintenance, and settings

Good results start before the print does. How your printer is set up, maintained, and tuned decides how much sanding, filling, and repair work you'll face later, as well as how long the part survives once it's painted and being worn. Time spent here is the cheapest smoothing you'll ever do.

These are the settings I use for cosplay armor. They've been refined through trial and error on our own builds. Your printer, filament brand, and environment may differ, but this is a strong starting point for dialing in your own workflow.

Tools & Materials

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Calibrate and maintain the printer first

Before any of the settings below, the printer itself needs to be dialed in. Calibration routines tune your particular printer in your environment. The environment has an effect on printer settings, and every filament brand and mix dials in differently. When you switch brands, or switch materials, recalibrate. The numbers that worked for the last spool won't necessarily carry over.

This is part of why I use Bambu Lab printers: they come pretty well dialed in from the factory, and the tuning I have to do for my particular environment is minimal. That's a preference, not a rule. The same routines dial in any printer.

The calibrations I like to run:

• Temperature tower. Finds the nozzle temp where this filament extrudes clean with minimal stringing.
• First layer. Dials nozzle height and flow so prints start flat and stick.
• Retraction. Tunes how far the filament pulls back on travel moves to stop stringing.
• Bridge flow. Sets how much material extrudes when the nozzle prints across open air.
• Overhangs. Shows the steepest angle your printer can print cleanly without support.
• Supports. Tests the interface gap so supports hold the part but still break away.
• Ironing. Tunes the smoothing pass the hot nozzle makes over flat top surfaces.

You don't have to build these tests yourself. Bambu Studio and OrcaSlicer both ship a calibration menu that generates the temperature tower, retraction tower, flow rate, pressure advance, and max flow tests for you. Bambu printers also auto-calibrate the machine side (bed leveling, nozzle height, vibration) and can auto-calibrate flow dynamics per filament; re-run that when you switch brands, and re-run the machine calibration after you move the printer, update firmware, or finish a maintenance cycle. PrusaSlicer has no built-in suite. Use the test models below, or Teaching Tech's calibration site, which generates the G-code in your browser.

The slicer menus don't cover everything on my list. These free test models fill the gaps:

• Unsupported bridge test: dial in bridge flow and bridge speed.
• Practical overhang test: find the real overhang angle your printer can handle.
• Support Z distance test: dial in the top Z distance so supports break away clean.
• Ironing calibration: tune the ironing pass for flat top surfaces.
• Initial layer flow ratio test: dial in the first-layer flow for a clean bottom surface.

Different settings get used at different times, and calibration is where you learn which. If an overhang is going to print as a true horizontal bridge (flat, out at ninety degrees), I set bridge flow to 1.7 with an overhang speed of 20 mm/s and a bridge top Z distance of 0.5 mm. For overhangs that aren't horizontal, bridge flow drops to 1, overhang speed to 50 mm/s, and top Z distance to 0.25 mm on a 0.2 mm layer height with a 0.4 nozzle. It's situational to the print and the part. You learn those calls by running the calibrations.

Maintenance

Keep the machine clean and running right. A lot of print problems get solved by simply tightening the belts or cleaning the lead screws, so check the mechanics before you start rewriting slicer settings.

My maintenance cycle is tightening the belts, cleaning the lead screws, and cleaning the carbon rods. After every cycle I re-run the machine calibration, so the printer's calibrations are in tune with how it's just been maintained.

Plate adhesion issues are nine times out of ten grease or some other defect with the plate. If the plate is clean and prints still won't hold, look at compatibility: a material and a plate that don't work together, or a plate that isn't compatible with the settings you're running.

Keeping the plate clean is most of the battle:

1. Deep clean with warm soapy water and a degreasing dish soap like Dawn, then dry the plate completely.
2. Between prints, a spritz of ammonia-based Windex or 99% alcohol and a wipe with a clean paper towel cuts down contamination, and with it, first layers coming undone.
3. Avoid touching the surface with bare hands. Skin oils are grease too.

In most cases you don't need glue, hairspray, or tape. If you're using glue to make a print stick, you've got some other problem and the glue is compensating for it, usually a dirty plate or a plate and material that aren't matched. Fix that instead. The legitimate use for a glue stick is the opposite job: as a release agent when a material sticks to the plate too well. A thin layer lets the part come off without damaging the plate. If a part is already stuck, let the bed cool fully, then ease it off with a thin spatula.

Choose your filament

Different filaments have different strengths and weaknesses depending on the use. Armor that's going to be worn is better in PETG for the added heat tolerance. If the piece is going to sit on a shelf in an air-conditioned room, PLA would probably be fine. But after all the work of finishing a part, I'm not going to risk it being left in the sun or a sunny room and warping. The tougher material is cheap insurance. Filament choice also affects strength, how it sands, and how paint adheres.

Color is irrelevant if the part will be painted. Primer and paint cover the base filament entirely.

Orient the model

Orientation mainly decides three things: how visible the layer lines end up, what supports the part needs, and where the support scarring lands. Sometimes reorienting a part removes the need for supports entirely, or moves them to a spot that's less visible on the finished piece. A perfectly flat base is not always the best choice. Prioritize surface finish over base contact when the trade saves post-processing time.

Surface quality

Layer stepping shows up worst on the top of the model, where surfaces run at shallow angles. The print resolves in steps of one layer height, so the closer a surface gets to horizontal, the more visible the stepping becomes. Curves and slight slopes are easier to smooth when they're not sitting directly on top of the model. Reorient the part to move them.

• Flat surfaces parallel to the build plate can use ironing to improve smoothness.

Strength considerations

• 3D prints are stronger when the stress runs across the layer lines rather than with them.
• If the part will carry any load, think about layer line orientation before committing.

Support considerations

• Rotate the model to minimize overhangs below your printer's threshold, usually around 45°.
• Add supports to overhangs the auto-support feature missed.
• Block supports where they aren't needed, such as the inside of most helmets.
• Orient the model so supports land where the scarring will be least visible on the finished part.

Optimizing orientation

• Minimize overhangs. Orient parts to keep angles below 45° where possible.
• Prioritize cosmetic surfaces. Align the surfaces that will be on display parallel to the build plate.
• Balance build time against finish. Vertical orientation can look better, but taller prints take more time.

Tune layer, walls, infill

Slicer settings determine the quality and durability of the part. Layer height controls resolution, but it also affects print time: taller layers print faster at the cost of the rich detail. A smaller layer height doesn't save you much sanding time, but it improves resolution so the final result is more crisp. Wall count and infill give the part its strength and control how lightweight it is: walls are stronger than infill, but infill keeps the walls from collapsing on larger parts.

The specific numbers in this guide are starting points. The calibrations will give you the proper settings for your machine, your material, and your environment.

Layer height

Layer height determines the resolution of your print. A lower layer height improves surface detail and makes fine engravings sharper, but it does not add part strength. It's a trade between appearance and print time:

• Lower layer height: more detail, longer prints.
• Higher layer height: faster prints, less detail.

Use lower layer heights only where the detail will actually be visible. Large, flat armor panels often look identical at 0.20 mm and print much faster.

• 0.20 mm works for most armor parts: clarity with speed.
• 0.16 mm is better for fine surface details like engraved text, panel lines, and decorative edges.

Wall count

Walls (also called perimeters) contribute more to strength than infill. Increasing wall count makes parts heavier and slower to print, but durability goes up significantly. If you need a stronger prop, add walls before adding infill. A thin-walled part with dense infill still cracks along the outer shell.

• 4–6 walls is a good standard for armor, helmets, and props that get handled.
• In many cases walls alone will create a fully solid part before infill matters.
• Extra infill density rarely matches the strength gain from more walls.

Infill pattern and density

Infill provides internal support for the print. The outer walls do most of the structural work; infill keeps the surfaces from collapsing or flexing. For large props, a low-density gyroid infill adds stability without wasting filament. If you need more durability, increase wall count rather than crank up the infill percentage.

• 5–10% gyroid balances weight, strength, and print time.
• Gyroid distributes stress in all directions, unlike grid or line patterns that create weak planes.

Configure supports

Supports provide a temporary structure for overhanging areas to print onto; they're meant to break away once the part is finished. Your support settings can make a huge difference in post-processing time. Supports fused to the part are hard to remove and leave significant scarring. The goal is a structure that prints reliably and breaks away cleanly.

Recommended: Tree (Slim or Hybrid)

• Tree supports use less material and are easier to remove than grid supports.
• The branching structure reaches overhangs in tight or intricate areas without flooding the part with support.
• Tree supports contact the model at fewer points: less marking, less cleanup after removal.

Interface settings

Top Z distance is the gap between the top of the support and the bottom of the part. Adjust in small steps:

• 0.16 mm layer height: start at 0.20 mm.
• 0.20 mm layer height: start at 0.25 mm.
• If supports fuse to the surface, increase Z distance by 0.04 mm.
• If overhangs droop, reduce Z distance.

The supports calibration finds where your printer actually lands with your material. Run it rather than trusting these numbers blind.

Interface pattern: Concentric support interfaces on curved surfaces reduce scarring and make sanding easier.

Speed settings

Bridge / overhang speed controls how fast the nozzle moves over an area with thin or no support beneath. Slower speeds give the filament time to cool and prevent drooping. The bridge flow and overhang calibrations give you the right speeds for your machine. My numbers are in the calibration section above.

Checkpoint: Ready to print

Once the print finishes, you're ready for Stage 02: Raw Print to Primer Ready.

FAQ

Why PETG over PLA?
Heat tolerance. A PLA helmet softens in a hot car or under stage lights; PETG holds its shape. PETG is a little fussier to print (needs drying) but worth the trade for armor that gets worn.

What slicer should I use?
Any modern slicer with tree supports and gyroid infill works: Bambu Studio, OrcaSlicer, and PrusaSlicer all do the job. The settings above translate across them; the labels and exact field names differ.

Do I really need to dry the filament?
If you're seeing stringing, surface blobs, or hissing/popping at the nozzle, yes. Even new spools can be wet enough to print badly. A few hours in a filament dryer fixes it.

How many walls is too many?
For armor, 4–6 walls is the sweet spot. More than that adds print time without meaningful strength.

Why gyroid instead of grid infill?
Gyroid distributes stress in all directions; grid creates weak planes along its lines. Gyroid also avoids the nozzle collisions that grid patterns sometimes cause when the infill crosses over previous lines.