<p>It looks like the top of your model (The lowest part in the picture) is wider than the bottom (The part in contact with the build plate).</p>
<p>This means that there is a substantial lip with nothing under it to support it, or to attach it to the build plate.</p>
<p>If I remember my rules of force correctly (and I may not) this means that the force excerpted on the part of the object furthest from the build plate is the square of the force on the part nearest to it that's touching the build plate.</p>
<p>By 3D printing standards this is quite a big number. You either need to angle the model to reduce this force (Draw a triangle from the corner to the big touching the base plate, and angle it so that the triangle is as shallow as possible, or to add additional material in to make that angle as shallow as possible.</p>
<p>I would suggest that you don't place your model flat on the build plate, instead angle it at maybe 30 and use heavy supports.</p>

CC BY-SA 4.0
2022-09-16T18:47:43.107Z
2022-09-16T18:47:43.107Z
Aaargh Zombies
<h2>Print orientation</h2>
<p>Your model is pulled up from the FEP film with a huge force. It releases from the film first at the corners, then progresses to the center. The force bends the model down as it is still flexible, so it creates a bent item.</p>
<p>This can be mitigated by reducing the area that you pull at. Commonly, you'll turn the item so the area is minimized, and you also might want to angle the item. This will cost some material in support structure, but you reduce the force on the part that can deform it in printing.</p>

CC BY-SA 4.0
2022-09-26T18:55:19.430Z
If the peel action bends the layer, wouldn’t it make it happy face shape, because the center gets sucked down relative to the rest of the layer, and peeled last? Here in the photo it is sad face shape.
ChinchillaWafers
CC BY-SA 4.0
2022-09-26T18:58:38.323Z
@ChinchillaWafers the forces are strongest on the edges, it pulls there first.
Trish
CC BY-SA 4.0
2022-09-15T08:40:24.467Z
2022-09-15T08:40:24.467Z
Trish
<ul>
<li><p>It's most likely that your bed does not mechanically reach the correct position before the printer starts curing the resin. Many printers and slicer software allow setting <code>wait_time_before_cure</code> to e.g. 6 s (I don't know about your printer/slicer). That means that once your bed has presumably reached its position for curing, it waits another 6 s to settle mechanically. If your slicer software does not allow to set <code>wait_time_before_cure</code> (or similarly named) but your printer can handle <code>wait_time_before_cure</code>, you can use the open source tool <a href="https://github.com/sn4k3/UVtools" rel="nofollow noreferrer">UVtools</a> to do that. (Edit: I just saw <a href="https://github.com/sn4k3/UVtools/discussions/626" rel="nofollow noreferrer">a discussion</a> so it's basically possible with your machine even though not optimally so.)</p>
</li>
<li><p>It's much less likely that your FEP has become less transparent towards the edges of the vat. You could fix that by putting a new FEP on.</p>
</li>
<li><p><strong>Bottom layer exposure</strong>: Once you increased <code>wait_time_before_cure</code>, you can go with something around 7 s.</p>
</li>
<li><p><strong>Z lift speed: 360 mm/sec</strong>: if the printer could achieve the acceleration necessary, it meant that your bed could jump within less than a second to the top of the rails :-) Set it to something in the order of 50 to 80 mm/s.</p>
</li>
<li><p>Peel force is very unlikely an issue with this 3D model and orientation on the print bed. We have printed 1000 s of similar models flat on the print bed, so orientation is likely ok.</p>
</li>
<li><p>Leveling of the bed seems ok as the peeling happens on all sides symmetrically? If it wasn't symmetrical, bad leveling might also have an influence.</p>
</li>
</ul>

CC BY-SA 4.0
2023-01-02T14:39:00.653Z
2023-01-02T15:57:06.867Z
2023-01-02T15:57:06.867Z
mpa
<p>I am having some trouble with model adherence to my print bed. As shown in the attached photo, my model is pulled away at the sides leaving it bowed even though it is designed to be flat. Other than this &quot;bowing&quot;, the model is of good quality.</p>
<p>The model is printed solid on an Anycubic Photon M3 Plus with Anycubic 3D Printing UV Sensitive Resin. My print settings are:</p>
<ul>
<li>Bottom layer count: 6</li>
<li>Bottom layer exposure: 22 secs (also tried 30 secs and 40 secs with the same results)</li>
<li>Normal layer height: 0.05 mm</li>
<li>Normal layer exposure: 2.5 secs</li>
<li>Off time: 0.5 secs</li>
<li>Z lift height: 6 mm</li>
<li>Z lift speed : 360 mm/sec</li>
<li>Z lift retract: 6 mm</li>
</ul>
<p>The bed is aligned. Could anyone suggest what is wrong and what I could try to remove this &quot;bowing&quot; effect?</p>
<p><a href="https://i.sstatic.net/VmF9H.jpg" rel="nofollow noreferrer" title="Resin printed model with a bowing effect"><img src="https://i.sstatic.net/VmF9H.jpg" alt="Resin printed model with a bowing effect" title="Resin printed model with a bowing effect" /></a></p>

<print-quality><adhesion><resin><build-plate>
How to keep model flat in resin printing?
Pyy
# How to keep model flat in resin printing?

(Asked by: username_0 on 2022-09-13)

I am having some trouble with model adherence to my print bed. As shown in the attached photo, my model is pulled away at the sides leaving it bowed even though it is designed to be flat. Other than this "bowing", the model is of good quality.

The model is printed solid on an Anycubic Photon M3 Plus with Anycubic 3D Printing UV Sensitive Resin. My print settings are:

* Bottom layer count: 6
* Bottom layer exposure: 22 secs (also tried 30 secs and 40 secs with the same results)
* Normal layer height: 0.05 mm
* Normal layer exposure: 2.5 secs
* Off time: 0.5 secs
* Z lift height: 6 mm
* Z lift speed : 360 mm/sec
* Z lift retract: 6 mm

The bed is aligned. Could anyone suggest what is wrong and what I could try to remove this "bowing" effect?

[![Resin printed model with a bowing effect](https://i.sstatic.net/VmF9H.jpg "Resin printed model with a bowing effect")](https://i.sstatic.net/VmF9H.jpg "Resin printed model with a bowing effect")

**Tags:** print-quality, adhesion, resin, build-plate


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## 3 answers

### Answer by username_1 on 2022-09-16. Score: 1 | Accepted answer

It looks like the top of your model (The lowest part in the picture) is wider than the bottom (The part in contact with the build plate).

This means that there is a substantial lip with nothing under it to support it, or to attach it to the build plate.

If I remember my rules of force correctly (and I may not) this means that the force excerpted on the part of the object furthest from the build plate is the square of the force on the part nearest to it that's touching the build plate.

By 3D printing standards this is quite a big number. You either need to angle the model to reduce this force (Draw a triangle from the corner to the big touching the base plate, and angle it so that the triangle is as shallow as possible, or to add additional material in to make that angle as shallow as possible.

I would suggest that you don't place your model flat on the build plate, instead angle it at maybe 30 and use heavy supports.


---

### Answer by username_2 on 2022-09-15. Score: 2

## Print orientation

Your model is pulled up from the FEP film with a huge force. It releases from the film first at the corners, then progresses to the center. The force bends the model down as it is still flexible, so it creates a bent item.

This can be mitigated by reducing the area that you pull at. Commonly, you'll turn the item so the area is minimized, and you also might want to angle the item. This will cost some material in support structure, but you reduce the force on the part that can deform it in printing.

> **Comments:**
> **username_3**: If the peel action bends the layer, wouldn’t it make it happy face shape, because the center gets sucked down relative to the rest of the layer, and peeled last? Here in the photo it is sad face shape.  
> **username_2**: @username_3 the forces are strongest on the edges, it pulls there first.  

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### Answer by username_4 on 2023-01-02. Score: 0

* It's most likely that your bed does not mechanically reach the correct position before the printer starts curing the resin. Many printers and slicer software allow setting `wait_time_before_cure` to e.g. 6 s (I don't know about your printer/slicer). That means that once your bed has presumably reached its position for curing, it waits another 6 s to settle mechanically. If your slicer software does not allow to set `wait_time_before_cure` (or similarly named) but your printer can handle `wait_time_before_cure`, you can use the open source tool [UVtools](https://github.com/sn4k3/UVtools) to do that. (Edit: I just saw [a discussion](https://github.com/sn4k3/UVtools/discussions/626) so it's basically possible with your machine even though not optimally so.)
* It's much less likely that your FEP has become less transparent towards the edges of the vat. You could fix that by putting a new FEP on.
* **Bottom layer exposure**: Once you increased `wait_time_before_cure`, you can go with something around 7 s.
* **Z lift speed: 360 mm/sec**: if the printer could achieve the acceleration necessary, it meant that your bed could jump within less than a second to the top of the rails :-) Set it to something in the order of 50 to 80 mm/s.
* Peel force is very unlikely an issue with this 3D model and orientation on the print bed. We have printed 1000 s of similar models flat on the print bed, so orientation is likely ok.
* Leveling of the bed seems ok as the peeling happens on all sides symmetrically? If it wasn't symmetrical, bad leveling might also have an influence.


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