<p>I printed this hook that must have 2.8 mm thickness of all walls:</p>
<p><img src="https://i.sstatic.net/HEMDi.png" alt="3D model with dimensions" /></p>
<p>But actual sizes differs:</p>
<p><a href="https://i.sstatic.net/TeqLG.jpg" rel="nofollow noreferrer" title="3D printed model of a hook with measurements notated"><img src="https://i.sstatic.net/TeqLG.jpg" alt="3D printed model of a hook with measurements notated" title="3D printed model of a hook with measurements notated" /></a></p>
<p>And I think this is a reason why the 3.0 mm wall has a gap.</p>
<p>Printed with Monoprice Select Mini v2, nozzle 0.4 mm, PLA at 210 °C, PrusaSlicer.</p>
<p>This issue isn't a casual fault, I printed the model several times and always have exactly the same issue.</p>
<p>What causes this inconsistency of sizes?</p>
<p><strong>UPDATE.</strong> Thanks to Oscar's comment:</p>
<blockquote>
<p>It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.</p>
</blockquote>
<p>Indeed, after rotating the model 45° I've get almost perfect print with almost perfect sizes of all walls.</p>
<p>Maybe I'm wrong, but I believe this is because of non-ideality of printer's mechanics and lots of paths parallel to X or Y axis in the model. For example, when the printer prints a path parallel to X, then Y axis is fixed. Then, to print an adjacent path, Y moved a little (= extrusion width), and because of non-ideality of Y mechanics, there's some error here. By placing the model such way that minimizes the paths when X or Y axis is fixed, it eliminates such defects by averaging the error.</p>

CC BY-SA 4.0
2022-02-25T20:19:13.967Z
How dimensionally accurate is your printer? Have you calibrated your 3D printer? How long ago? If you need more info see [What prints can I do to test/calibrate my printer for precision?](https://3dprinting.stackexchange.com/questions/6470/what-prints-can-i-do-to-test-calibrate-my-printer-for-precision/6478#6478)
agarza
CC BY-SA 4.0
2022-02-25T20:23:08.860Z
@agarza: I never calibrate it, but you can see that some sizes are exactly the same as in the model, but some other differs. I think all sizes would changed if the problem was in the calibration.
Canis Lupus
CC BY-SA 4.0
2022-02-25T22:07:15.020Z
Calibration for one axis will not automatically calibrate another. I do find it interesting that both of the horizontal members are different sizes; the same as the vertical ones.
agarza
CC BY-SA 4.0
2022-02-25T23:13:30.427Z
It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.
0scar
CC BY-SA 4.0
2022-02-25T23:21:52.783Z
Slop in the relevant belt looks like the most plausible cause.
R.. GitHub STOP HELPING ICE
<print-quality><underextrusion><monoprice-select-mini><dimensional-accuracy>
What causes inconsistency of sizes?
Canis Lupus
# What causes inconsistency of sizes?

(Asked by: username_0 on 2022-02-25)

I printed this hook that must have 2.8 mm thickness of all walls:

![3D model with dimensions](https://i.sstatic.net/HEMDi.png)

But actual sizes differs:

[![3D printed model of a hook with measurements notated](https://i.sstatic.net/TeqLG.jpg "3D printed model of a hook with measurements notated")](https://i.sstatic.net/TeqLG.jpg "3D printed model of a hook with measurements notated")

And I think this is a reason why the 3.0 mm wall has a gap.

Printed with Monoprice Select Mini v2, nozzle 0.4 mm, PLA at 210 °C, PrusaSlicer.

This issue isn't a casual fault, I printed the model several times and always have exactly the same issue.

What causes this inconsistency of sizes?

**UPDATE.** Thanks to Oscar's comment:

> It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.

Indeed, after rotating the model 45° I've get almost perfect print with almost perfect sizes of all walls.

Maybe I'm wrong, but I believe this is because of non-ideality of printer's mechanics and lots of paths parallel to X or Y axis in the model. For example, when the printer prints a path parallel to X, then Y axis is fixed. Then, to print an adjacent path, Y moved a little (= extrusion width), and because of non-ideality of Y mechanics, there's some error here. By placing the model such way that minimizes the paths when X or Y axis is fixed, it eliminates such defects by averaging the error.

**Tags:** print-quality, underextrusion, monoprice-select-mini, dimensional-accuracy
> **Comments:**
> **username_1**: How dimensionally accurate is your printer? Have you calibrated your 3D printer? How long ago? If you need more info see [What prints can I do to test/calibrate my printer for precision?](https://3dprinting.stackexchange.com/questions/6470/what-prints-can-i-do-to-test-calibrate-my-printer-for-precision/6478#6478)  
> **username_0**: @agarza: I never calibrate it, but you can see that some sizes are exactly the same as in the model, but some other differs. I think all sizes would changed if the problem was in the calibration.  
> **username_1**: Calibration for one axis will not automatically calibrate another. I do find it interesting that both of the horizontal members are different sizes; the same as the vertical ones.  
> **username_2**: It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.  
> **username_3**: Slop in the relevant belt looks like the most plausible cause.  

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## 0 answers

