<p>The issue you are having is with bed adhesion.  Basically your print is not sticking well enough to the printer bed for it to resist the mechanical forces the part is being subject to during print.</p>

<p>This the most common issue in FDM 3D printing and you can find a lot of material online on how to mitigate the problem.  Just as a "teaser":</p>

<ul>
<li>You need to ensure your <strong>printing bed is dead flat and at the right distance</strong> from your nozzle.  Search online for: "3D printer bed leveling": the procedure is normally <a href="https://pinshape.com/blog/6-simple-steps-to-3d-printer-bed-leveling/" rel="nofollow noreferrer">the same for most printers</a>, but if your model is a common one, chances are you will find a video/how-to/blog post for it.</li>
<li>You should use <strong>print settings that facilitate bonding</strong> of the plastic to the bed (typically: slow speed, no cooling fan, a bit of overextrusion...)</li>
<li>You can tell the slicer to <strong><a href="https://rigid.ink/blogs/news/3d-printed-raft-brim-skirt" rel="nofollow noreferrer">add a <em>brim</em> or a <em>raft</em></a></strong> to your part, to increase the amount of material holding down the print.</li>
<li>You have the option to <strong>cover your printing bed with some material that increases the bonding</strong> of the plastic (this is type-of-plastic specific but typically: PVA glue or painter's tape work well for PLA, and kapton tape or ABS sludge for ABS).</li>
<li><strong>If you have a heated bed, use it</strong> (each filament brand has their own recommendations, but typically 50-60°C works well for PLA).</li>
</ul>

<p>As for <em>why</em> your problem is happening towards the end of the print, there are a series of factors contributing to it:</p>

<ul>
<li><strong>The tallest the print, the more mechanical advantage</strong> (leverage) the nozzle has over the adhesion surface.</li>
<li><strong>It looks like your top layers are progressively small, so they print very fast and this in turn the does not allow for the plastic to completely cool down</strong> before going to the following layer, so when the nozzle prints on top of it the still-warm layer is "pulled up" by the action of the nozzle, creates a blob that sticks to the nozzle and that only makes situation worse.  Snowball effect.  Most slicers have an option "minimum layer time" that delays the print of a layer until X seconds have passed from the start of the previous one.</li>
<li><strong>It may be possible that the Z axis is inaccurate and the nozzle catches on a previous layer</strong>.  Most printer have some kind of accuracy issue with the Z axis the furthest up the head is, especially if the Z-axis has only one threaded rod (as for example in the Creality CR-10).  Another source of inaccuracy (see comments below) could be the movement multiplier for the Z being slightly off, causing the nozzle to dig into the print if there's overextrusion and enough cumulative error.  Z axis inaccuracies are however unlikely to be the primary source of troubles for you, but it's a "nice to know" thing to know about 3D FDM printers, nevertheless.</li>
</ul>

CC BY-SA 3.0
2018-01-15T15:46:26.137Z
*printing bed should* be **heated bed**?

In addition to the Z axis inaccuracy, the movement multiplier for the Z axis might be off, causing the nozzle to dig into the print if there's overextrusion and enough cumulative error.
Onno
CC BY-SA 3.0
2018-01-15T16:02:33.687Z
@onno -  thanks, fixed! will add your comment in the answer when not on mobile! :)
mac
CC BY-SA 3.0
2018-01-15T07:45:54.233Z
2018-01-16T00:53:06.700Z
2018-01-16T00:53:06.700Z
mac
<p>I recently got my first 3D printer, however when I print taller objects, sometimes the piece pops off the build plate and moves around before the print is finished, the piece then is missing the top few layers and is burnt from the nozzle, Just wondering why this happens and how to fix it...</p>

<p>Here are some pictures:
<a href="https://i.sstatic.net/ZRFLp.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZRFLp.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/81LY5.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/81LY5.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2018-01-15T00:56:07.557Z
It's unclear what your question is: if it is about how to improve adhesion, you should provide more details.  What printer, what filament, what type of printing bed, what temperatures, etc...  Or maybe the question is about why it happens at the top of the print?
mac
CC BY-SA 3.0
2018-01-15T03:34:54.330Z
I have updated the post, sorry about that! I also believe that it was due to bed leveling as the first layer did not have a lot of contact to the print surface...
Xander1111
<adhesion>
3d Print pops off before complete
Xander1111
# 3d Print pops off before complete

(Asked by: username_0 on 2018-01-15)

I recently got my first 3D printer, however when I print taller objects, sometimes the piece pops off the build plate and moves around before the print is finished, the piece then is missing the top few layers and is burnt from the nozzle, Just wondering why this happens and how to fix it...

Here are some pictures:
[![enter image description here](https://i.sstatic.net/ZRFLp.jpg)](https://i.sstatic.net/ZRFLp.jpg)

[![enter image description here](https://i.sstatic.net/81LY5.jpg)](https://i.sstatic.net/81LY5.jpg)

**Tags:** adhesion

> **Comments:**
> **username_1**: It's unclear what your question is: if it is about how to improve adhesion, you should provide more details.  What printer, what filament, what type of printing bed, what temperatures, etc...  Or maybe the question is about why it happens at the top of the print?  
> **username_0**: I have updated the post, sorry about that! I also believe that it was due to bed leveling as the first layer did not have a lot of contact to the print surface...  

---

## 1 answers

### Answer by username_1 on 2018-01-15. Score: 1

The issue you are having is with bed adhesion. Basically your print is not sticking well enough to the printer bed for it to resist the mechanical forces the part is being subject to during print.

This the most common issue in FDM 3D printing and you can find a lot of material online on how to mitigate the problem. Just as a "teaser":

* You need to ensure your **printing bed is dead flat and at the right distance** from your nozzle. Search online for: "3D printer bed leveling": the procedure is normally [the same for most printers](https://pinshape.com/blog/6-simple-steps-to-3d-printer-bed-leveling/), but if your model is a common one, chances are you will find a video/how-to/blog post for it.
* You should use **print settings that facilitate bonding** of the plastic to the bed (typically: slow speed, no cooling fan, a bit of overextrusion...)
* You can tell the slicer to **[add a *brim* or a *raft*](https://rigid.ink/blogs/news/3d-printed-raft-brim-skirt)** to your part, to increase the amount of material holding down the print.
* You have the option to **cover your printing bed with some material that increases the bonding** of the plastic (this is type-of-plastic specific but typically: PVA glue or painter's tape work well for PLA, and kapton tape or ABS sludge for ABS).
* **If you have a heated bed, use it** (each filament brand has their own recommendations, but typically 50-60°C works well for PLA).

As for *why* your problem is happening towards the end of the print, there are a series of factors contributing to it:

* **The tallest the print, the more mechanical advantage** (leverage) the nozzle has over the adhesion surface.
* **It looks like your top layers are progressively small, so they print very fast and this in turn the does not allow for the plastic to completely cool down** before going to the following layer, so when the nozzle prints on top of it the still-warm layer is "pulled up" by the action of the nozzle, creates a blob that sticks to the nozzle and that only makes situation worse. Snowball effect. Most slicers have an option "minimum layer time" that delays the print of a layer until X seconds have passed from the start of the previous one.
* **It may be possible that the Z axis is inaccurate and the nozzle catches on a previous layer**. Most printer have some kind of accuracy issue with the Z axis the furthest up the head is, especially if the Z-axis has only one threaded rod (as for example in the Creality CR-10). Another source of inaccuracy (see comments below) could be the movement multiplier for the Z being slightly off, causing the nozzle to dig into the print if there's overextrusion and enough cumulative error. Z axis inaccuracies are however unlikely to be the primary source of troubles for you, but it's a "nice to know" thing to know about 3D FDM printers, nevertheless.

> **Comments:**
> **username_2**: *printing bed should* be **heated bed**?  In addition to the Z axis inaccuracy, the movement multiplier for the Z axis might be off, causing the nozzle to dig into the print if there's overextrusion and enough cumulative error.  
> **username_1**: @username_2 -  thanks, fixed! will add your comment in the answer when not on mobile! :)  

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