The first layer of a 3D print is possibly the most important part of the whole printing process. The first layer is the foundation of the whole model, and issues in this layer will affect the quality, stability, and overall success of your print.
1. Incorrect Bed Leveling
The Problem
For a good first layer bond, the print bed needs to be perfectly level and precisely spaced from the nozzle.
Why It Happens
● Manual Leveling Errors: Most consumer 3D printers will rely on user manual bed leveling. Inconsistent adjustment/leveling, or other human mistakes, can lead to an uneven bed.
● Warped Print Bed: Over time, your print bed surfaces will warp by thermal expansion and contraction.
● Auto-Leveling Issues: Even auto-bed-leveling printers are susceptible to failure as the onboard sensors can sometimes become miscalibrated.
Technical Details
The perfect distance between the nozzle and the bed is typically around 0.1–0.2 mm about the thickness of a sheet of paper for most 0.4 mm nozzles
Solutions
● Manual Leveling: Use a piece of paper or feeler gauge to set the nozzle-to-bed distance.
● Auto-Leveling Calibration: If you have auto leveling make sure that you are checking the sensor and Z-offset
● Check Bed Flatness: Use a straightedge or ruler to check that the bed is flat. If warped, replace it with a decent quality glass or PEI (Polyetherimide) coated surface.
● Regular Maintenance: Re-level the bed on a regular basis, especially since thermal cycling of the bed will distort the bed thickness.
2. Improper Bed Surface Preparation
The Problem
The surface of the print bed is an incredibly important factor in good filament adhesion. A dirty, oily, or "non-compatible" bed surface can lead to parts not sticking due to filament not sticking to the bed.
Why It Happens
● Contamination: Prints can come into contact with Fingerprints / Dust / Residue from previous prints, all of which can limit adhesion.
● Incompatible Surface: Some filaments, such as PETG and TPU, do better if they stick to a certain bed surface such as PEI, glass, or other textured sheets.
● Worn-Out Surface: The bed surface will deteriorate over time and lose its adhesion properties.
Technical Details
Some filaments require some different bed surface qualities. For example:
● PLA: PLA can stick to clean glass, PEI or blue painter's tape.
● ABS: ABS will not stick at room temperature unless your bed is heated to (80-100 degrees) Celsius, or if you smear glue stick
● PETG: PETG will stick very well to PEI or glass, but can destroy the surface of PEI or glass if it is not removed carefully.
Surface energy of material (the amount of ability material has to attract and hold filament.
Solutions
● Clean the Bed: Depending on the residue on the glass bed, wipe with isopropyl alcohol (at least 90% or more) to wipe off oils and debris.
● Choose the Right Surface: You must match the correct bed surface with your filament. For example, if printing PETG you would use a PEI sheet; for abs you would typically use a glass bed with a glue stick.
● Apply Adhesion Aids: For those materials that have issues adhering to the build surface you can also use glue stick, hairspray or painter’s tape.
● Replace Worn Surfaces: If you’re still having issues where the model won’t adhere and you start getting adhesion issues, replace the build surface altogether
3. Incorrect Nozzle and Bed Temperature
The Problem
The temperatures set on the nozzle and the bed strongly affect first layer adhesion as well as the first layer quality of the original layer. The wrong temperature can lead to under-extrusions, over-extrusions or it won’t adhere to the bed.
Why It Happens
● Filament-Specific Requirements: Each style of filament (PLA, ABS, PETG, etc.) has a specification temperature range for extrusion and therefore will define an optimal adhesion.
● Ambient Conditions: all filaments behave differently in cold or drafty environments, where the filament will cool way too quickly and not properly adhere to the bed.
● Temperature Calibration Issues: The issues also could stem from miscalibrated thermistors or miscalibrated heaters to not achieving the right temperature.
Technical Details
● PLA: Nozzle temp is typically between 190–220°C; Bed temp can range from 50–60°C
● ABS: Between 220–250°C for the nozzle; bed temp between 90–110°C or you will experience warping
● PETG: Nozzle: 230-250C Bed:70-80C
If the nozzle is too low in temperature, the filament will not flow properly, creating gaps, and or weak adhesion. If the nozzle temperature is too high, the filament will ooze out of the nozzle.
Solutions
● Check Filament Specifications: Check the recommendations from the filament manufacturer about the reference temperature settings for the filament.
● Calibrate Temperatures: Use a thermal probe to confirm that the nozzle and bed get to the correct temperatures.
● Adjust for Environment: In very cold rooms, the bed temperature should increase slightly or use an enclosure.
● Test Prints: Try printing test prints at small increments (typically around 5C)of the temperatures, to see where it best works for your filament.
4. Incorrect First Layer Settings in Slicer
The Problem
Slicer settings, such as layer height, print speed, and flow rate, all impact the first layer quality. If these settings are not correct, there will be issues with under-extrusion or over-extrusion.
Why It Happens
● Layer Height: If the first layer height is too thick, the filament will not squish; however, if it is too thin, the filament will over-extrude.
● Print Speed: If the print speed is too high, the filament has not enough time to stick to the bed,
● Flow Rate: Incorrect extrusion multiplier settings can lead to too much or too little filament to be placed.
Technical Details
● Layer Height: The first layer's height is usually set to 100-150% of the "regular" layer height (e.g. 0.2-0.3 mm height for a 0.2 mm "standard" layer) to aid in bed adhesion.
● Print Speed: First layers should be printed at lower speeds (20-30 mm/s) to allow the filament time to bond better.
● Flow Rate: It is helpful to set the first layer flow rate slightly higher (100-110%).
Solutions
● Optimize Layer Height: Set your first layer height to 0.2-0.3 mm height when using a 0.4 mm nozzle.
● Reduce First Layer Speed: Set the first layer speed at 20-30 mm/s in your slicer settings.
● Adjust Flow Rate: A very slight increase (e.g. 105% flow rate) of the first layer flow rate will make sure enough filament is being placed down on the first layer.
● Use Slicer Presets: Start your configuration by using your slicer's defaults for your filament and adjust parts of it for your needs.
5. Filament Issues
The Problem
The issues with the first layer can also come from the filament, especially if it is old, contaminated or not properly stored.
Why It Happens
● Moisture Absorption: Filaments such as ABS, PETG, and Nylon are hygroscopic in nature which means they will absorb moisture from the air. This can create inconsistencies in the extrusion and in-bed adhesion.
● Degraded Filament:Old filaments, poor filament, etc. can have inconsistencies in running diameter or chemical degradation which affect the flow.
● Incorrect Filament Type: Usage of a filament that is not appropriate for your printer configuration can cause issues.
Technical Details
Moisture in a filament can create steam bubbles during extrusion, causing a popping sound, uneven flow, and adhesion problems. Filament diameter discrepancies.
Solutions
● Dry Filament: Always store filament in airtight bags or containers with desiccant material. Wet filament can be dried using a filament dryer or an oven at low temperatures
● Check Filament Quality: Measure the filament diameter using calipers to ensure you are using a uniform diameter filament.
● Match Filament to Printer: Be sure that extruder and hotend configuration is appropriate for the filament being used.
6. Mechanical Issues
Source: https://youtu.be/uvlMeTnjriQ?si=_bf-K3GUvXyB0PB6
The Problem
Mechanical problems such as loose components or worn parts can affect extrusion speed or filament path inconsistently which can affect the first layer.
Why It Happens
● Loose Belts or Pulleys: Loose belts on the X or Y axis can cause unintended motion creating unevenness or misalignment to the first layers.
● Worn Nozzle: A worn or clogged nozzle can cause problems with filament flow.
● Z-Axis Issues: Any binding or backplay in the Z axis will create inconsistent nozzle height.
Technical Details
Mechanical play such as loose belts or pulleys can cause vibration or positioning error in the print.
Solutions
● Tighten Belts and Pulleys: Identify and tighten all belts and pulleys accordingly to remove any play.
● Replace Nozzle: Check the nozzle for wear and or clogging and replace as required.
● Lubricate Z-Axis: Clean and lubricate the Z-axis rods/leadscrews to ensure better movement.
● Check Frame Stability: Confirm that the printer frame is rigid and square so that as little vibration is introduced during the print.
