Roughness Underlying Layer of 3D Printing: Causes, Correctifs, and Prevention

Have you ever pulled a 3Impression D off the build platform, only to find its bottom layer looks bumpy, inégal, or covered in tiny gaps? That’s the roughness underlying layer of 3D printing—a common issue that ruins the look and functionality of your parts. Whether you’re making a PLA phone stand or an ABS mechanical component, a rough base can make the part unstable (Par exemple, a wobbly cup) or incompatible with other pieces. This guide breaks down why this happens and how to get a smooth, professional-looking first layer every time.

1. What Is the Roughness Underlying Layer of 3D Printing?

Le roughness underlying layer of 3D printing refers to an uneven, texturé, or flawed bottom layer of a 3D-printed part. This layer is the first one laid down on the build platform, and its quality sets the tone for the entire print. A rough base might have:

• Bumpy surfaces (like sandpaper texture).
• Gaps between filament lines (where the plastic didn’t stick properly).
• Blobs of excess plastic (from over-extrusion).

Par exemple, a 3D-printed PLA coaster with a rough underlying layer won’t sit flat on a table—every bump will make it rock back and forth. Pour les pièces fonctionnelles (Par exemple, a 3D-printed gear), gaps in the first layer can weaken the part, leading to breakage under pressure.

2. 3 Key Causes of Rough Underlying Layers (Avec des exemples du monde réel)

To fix rough 底层 layers, you need to target their root causes. Below are the three most common issues, backed by scenarios you might recognize:

Cause 1: Temperature Mismatches

Temperature is the #1 culprit for rough first layers. Both the nozzle and build platform need to be at the right heat to melt and bond filament properly:

• Nozzle Temperature Too Low: Pour PLA, the ideal nozzle temp is 180–210°C; pour les abdos, it’s 230°C+. If you set a PLA nozzle to 170°C, the plastic won’t melt fully—it will come out as lumpy strands instead of a smooth line, creating a rough base.
• Build Platform Temperature Too Low: PLA needs a bed temp of 50–60°C; ABS requires 90–110°C. A cold bed (Par exemple, 40° C pour PLA) makes the first layer cool too fast. The plastic shrinks before it can spread evenly, leaving gaps and bumps.
• Room Temperature Too Cold: FDM printers work best in 10–40°C environments. If your printer is in a drafty garage at 5°C, the first layer will cool instantly after touching the bed—creating a brittle, surface rugueuse.

Exemple: A hobbyist printing a PLA figurine in a cold basement (8° C) noticed the first layer had tiny cracks and uneven lines. Raising the room temp to 20°C and the bed temp to 55°C fixed the issue.

Cause 2: Printer Leveling Issues

A poorly leveled printer means the nozzle is too close to or too far from the build platform—both lead to rough layers:

• Nozzle Too Far: If the gap between the nozzle and platform is more than 0.2mm, the filament won’t press firmly against the bed. It will form thin, stringy lines with gaps between them—like drawing with a dry marker.
• Nozzle Too Close: If the gap is less than 0.1mm, the nozzle will scrape the platform. This squishes the filament unevenly, creating blobs and rough patches (like smearing paint with a too-tight brush).

The optimal gap is the thickness of a standard A4 sheet of paper. Many users skip this step, but it’s the easiest way to fix rough layers.

Cause 3: Damaged or Uneven Print Platforms

Even if your printer is level, a warped or scratched platform will ruin the first layer:

• Warped Platforms: Au fil du temps, glass or metal platforms can bend (Par exemple, from repeated heating and cooling). A warped platform has high and low spots—where it’s high, the nozzle is too close (causing blobs); where it’s low, the nozzle is too far (causing gaps).
• Scratched or Damaged Surfaces: If you’ve ever pried a stuck print off the platform with a knife, you might have scratched the surface. These scratches catch the filament, creating rough, lignes inégales. For magnetic frosted platforms, deep scratches can break the surface, making it impossible for filament to stick evenly.

Exemple: A small manufacturer using an ABS printer noticed every print had a rough base. Après vérification, they found the glass platform had a crack from a dropped tool—replacing the platform fixed the issue immediately.

3. 5 Step-by-Step Fixes for Rough Underlying Layers

Now that you know the causes, let’s dive into actionable solutions. These fixes are organized from easiest (Aucun outil nécessaire) to most involved (replacing parts):

Réparer 1: Calibrate Nozzle and Bed Temperatures

Start with temperature—this is the fastest fix for most users. Suivez ces directives:

How to test: Print a small 5x5cm square. If the lines are bumpy, raise the nozzle temp by 5°C. If there are blobs, lower it by 5°C. Repeat until the lines are smooth.

Réparer 2: Level the Printer Properly

Printer leveling is simple—you just need an A4 sheet of paper. Voici comment:

1. Turn on the printer and move the nozzle to the center of the platform.
2. Slide an A4 sheet between the nozzle and platform.
3. Adjust the bed leveling knobs (most printers have 3–4) until the paper feels like it’s “catching” slightly—you should feel gentle resistance when pulling it out.
4. Repeat this process at 3–4 other spots on the platform (Par exemple, corners and center) to ensure the entire surface is level.

Pour la pointe: Print a “leveling test” (un mince, large circle) pour vérifier. If the circle is smooth all the way around, your printer is level.

Réparer 3: Replace or Repair Damaged Platforms

If your platform is warped, scratched, or cracked, it’s time to fix or replace it:

• For Glass Platforms: If there are small scratches, clean the surface with isopropyl alcohol (90%+) to remove residue—sometimes scratches look worse than they are. For cracks or warping, replace the glass (they cost \(10- )20 online).
• For Magnetic Frosted Platforms: Deep scratches mean the surface is ruined—replace the magnetic sheet (généralement \(5- )15). If the platform is warped, try placing a thin sheet of glass on top (this creates a flat surface).

Réparer 4: Adjust Nozzle Height and Extrusion Rate

Even a level printer needs fine-tuning for the first layer:

• Nozzle Height: After leveling, set the “first layer height” in your slicing software (Par exemple, Traitement) to 0.2mm—this is thick enough to cover gaps but thin enough for a smooth surface.
• Extrusion Rate: If the first layer has gaps, increase the extrusion rate by 5% (Par exemple, depuis 100% à 105%). If there are blobs, decrease it by 5%. This controls how much plastic the nozzle pushes out—too little, and you get gaps; trop, and you get blobs.

Réparer 5: Use Adhesives to Improve Bed Stickiness

Parfois, even the right temperature and leveling aren’t enough—adhesives help the filament stick firmly, preventing gaps:

• Pour PLA: Use PVP solid glue (apply a thin layer with a brush) or hairspray (light coat). Both help the first layer bond without leaving residue.
• Pour les abdos: Use ABS slurry (mix ABS filament shavings with acetone) or specialized 3D print tape. ABS is trickier to stick, so these stronger adhesives keep the first layer flat.

4. Yigu Technology’s Perspective on Rough Underlying Layers

À la technologie Yigu, Nous avons aidé 300+ clients—from hobbyists to small factories—fix rough underlying layers. La plus grosse erreur que nous voyons? Skipping printer leveling. Many users rely on “auto-leveling” features, but manual checks with an A4 sheet are still the most reliable way to get a smooth base.

Our pro tip: For clients printing large parts (Par exemple, 30cm PLA signs), we recommend combining a glass platform with a bed leveling sensor. The sensor auto-adjusts for small platform warps, and the glass provides a flat surface—cutting rough layer rates by 85%. We also remind users to clean the platform with isopropyl alcohol before every print—residue from old filament is a hidden cause of uneven layers. À mesure que les matériaux d’impression 3D évoluent (Par exemple, flexible TPU), we update our guidelines to ensure smooth first layers for every type.

FAQ: Your Top Rough Underlying Layer Questions Answered

T1: My PLA print’s first layer is still rough even after leveling—what’s wrong?

A1: Check your nozzle temperature and extrusion rate. If the temp is below 180°C, the PLA won’t melt fully—raise it by 5–10°C. If there are gaps, increase the extrusion rate by 5% (in Cura or your slicer). Aussi, make sure your bed is at 50–60°C—cold beds cause PLA to shrink and gap.

T2: Can I sand a rough underlying layer to make it smooth?

A2: Oui! For PLA or ABS parts, Utilisez du papier de verre à grains fins (400–800 grain) to gently sand the bottom layer. Sand in circular motions until the surface is smooth. Just be careful not to sand too hard—you could thin the part or damage its shape. This works best for non-functional parts (Par exemple, figurines décoratives).

T3: Do I need a heated bed to avoid rough underlying layers?

A3: Cela dépend du matériau. PLA can sometimes print without a heated bed (if the room is 20–25°C), but a heated bed (50–60 ° C) drastically reduces roughness by keeping the first layer warm and sticky. Pour les abdos, Pivot, ou tpu, a heated bed is a must—cold beds will always cause rough, gapped layers.