> ## Documentation Index
> Fetch the complete documentation index at: https://stem-docs.intellectualpoint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting common problems

> Recognize and fix the most common 3D print failures - poor adhesion, warping, stringing, layer shifting, and extrusion issues.

## Every printer has bad days

Even experienced makers get failed prints. The skill is not avoiding every failure - it is **recognizing what went wrong and fixing it**. This page is your field guide to the most common problems on an FDM printer.

<Info>
  When a print fails, ask which stage failed: **design, slicing, loading, heating, leveling, or adhesion?** Working through the print journey in order finds the cause fast.
</Info>

## The most common problems

<Frame caption="A visual field guide to the most common FDM print failures and what causes them">
  <img src="https://mintcdn.com/intellectualpoint/O9vEZP6xEEMFLHva/images/intro3d/troubleshooting-guide.png?fit=max&auto=format&n=O9vEZP6xEEMFLHva&q=85&s=ebd77c188872f5659c96ac7036d916cf" alt="Diagram of common 3D print failures including warping, stringing, layer shift, and poor adhesion" width="1536" height="1024" data-path="images/intro3d/troubleshooting-guide.png" />
</Frame>

<AccordionGroup>
  <Accordion title="Poor bed adhesion - print won't stick" icon="circle-off">
    **Symptoms**: First layer peels up, print detaches, or nothing sticks at all.

    **Fixes**:

    * Re-level the bed - the nozzle is probably too far from the bed
    * Clean the surface with soap and water or isopropyl alcohol (skin oils ruin adhesion)
    * Add a thin layer of glue stick or use painter's tape
    * Slow down the first layer and add a **brim** or **raft** in Cura

    <Frame caption="Skirts, brims, and rafts each help the first layer grip the bed">
      <img src="https://mintcdn.com/intellectualpoint/O9vEZP6xEEMFLHva/images/intro3d/adhesion-helpers.png?fit=max&auto=format&n=O9vEZP6xEEMFLHva&q=85&s=022302a26a5ac69ba51c2ac60467afb4" alt="Diagram comparing skirt, brim, and raft build-plate adhesion helpers" width="1536" height="1024" data-path="images/intro3d/adhesion-helpers.png" />
    </Frame>
  </Accordion>

  <Accordion title="Warping - corners lift off the bed" icon="corner-up-left">
    **Symptoms**: Corners curl up, the bottom is no longer flat.

    **Fixes**:

    * Raise the bed temperature slightly
    * Reduce drafts - close windows or use an enclosure
    * Add a brim for more grip
    * Use PLA (it warps far less than ABS)
  </Accordion>

  <Accordion title="Stringing and oozing - thin plastic hairs" icon="minus">
    **Symptoms**: Fine strands of plastic strung between parts of the print.

    **Fixes**:

    * Enable or increase **retraction** in Cura
    * Lower the print temperature by 5-10 C
    * Dry your filament - wet filament strings badly

    <Frame caption="Retraction pulls filament back during travel moves to stop oozing and stringing">
      <img src="https://mintcdn.com/intellectualpoint/O9vEZP6xEEMFLHva/images/intro3d/stringing-diagram.png?fit=max&auto=format&n=O9vEZP6xEEMFLHva&q=85&s=0c7086c6e1cfbb7d5b0b45464bdb99b2" alt="Diagram showing how retraction prevents stringing between print parts" width="1536" height="1024" data-path="images/intro3d/stringing-diagram.png" />
    </Frame>
  </Accordion>

  <Accordion title="Layer shifting - print looks sliced sideways" icon="move-horizontal">
    **Symptoms**: Upper layers are offset from lower ones.

    **Fixes**:

    * Check and tighten the **X and Y belts**
    * Make sure nothing is blocking the moving bed or gantry
    * Slow the print speed
  </Accordion>

  <Accordion title="Under-extrusion - gaps and thin walls" icon="circle-dashed">
    **Symptoms**: Missing plastic, gaps between lines, weak layers.

    **Fixes**:

    * Check for a partial nozzle clog
    * Make sure the extruder gear grips the filament (check the tension arm)
    * Raise the temperature slightly and check filament diameter
  </Accordion>

  <Accordion title="Over-extrusion - blobs and rough tops" icon="circle">
    **Symptoms**: Too much plastic, blobby corners, rough top surfaces.

    **Fixes**:

    * Lower the **flow rate** in Cura
    * Lower the temperature slightly
  </Accordion>

  <Accordion title="Spaghetti - a tangled mess" icon="waves">
    **Symptoms**: The print detached mid-way and the nozzle kept extruding into the air.

    **Fixes**:

    * Almost always a first-layer/adhesion problem - re-level and clean the bed
    * Watch the first few layers of every print before walking away
  </Accordion>
</AccordionGroup>

## The paper-test refresher

Most first-layer problems come back to **bed leveling**. If prints stop sticking, re-run the paper test:

* **Too far** (paper slides freely): filament will not stick - turn the knob clockwise to raise the bed
* **Too close** (paper rips or won't move): nozzle scrapes and clogs - turn the knob counterclockwise to lower the bed
* **Just right**: slight resistance on the paper, like a light drag

## A simple debugging mindset

<Steps>
  <Step title="Change one thing at a time" icon="sliders-horizontal">
    If you change five settings at once, you will not know which one fixed it.
  </Step>

  <Step title="Watch the first layer" icon="eye">
    Most failures reveal themselves in the first two minutes. Stay and watch.
  </Step>

  <Step title="Write down what you tried" icon="notebook-pen">
    Keep notes so you can repeat what works and skip what does not.
  </Step>
</Steps>

<Tip>
  A failed print is not wasted - it is data. The best capstone presentations on Day 5 explain a failure and the fix. That problem-solving is worth real points.
</Tip>