<blockquote>
<p>wondering if the intensity of the radius had mattered.</p>
</blockquote>
<p>Yes it does if it's an overhang.</p>

CC BY-SA 4.0
2022-06-03T23:18:00.407Z
2022-06-03T23:18:00.407Z
Kilisi
<p>You can print a fillet without support as support material causes other issues like problems with removing supports and ugly scarring on you print. However, a fillet will cause an overhang when you slice the object</p>
<p><a href="https://i.sstatic.net/mXpkz.png" rel="noreferrer"><img src="https://i.sstatic.net/mXpkz.png" alt="enter image description here" /></a></p>
<p>and may result into poor results as well, see e.g. this:</p>
<p><a href="https://i.sstatic.net/hxKxd.png" rel="noreferrer"><img src="https://i.sstatic.net/hxKxd.png" alt="enter image description here" /></a></p>
<p>If your design allows it you should better use a chamfer than a fillet for the base of the print object.</p>
<p>A chamfer prints better than a fillet because a fillet creates an overhang (see indicated area on the left part of the image below.</p>
<p><a href="https://i.sstatic.net/fiFxU.png" rel="noreferrer"><img src="https://i.sstatic.net/fiFxU.png" alt="enter image description here" /></a>
<em>Image from <a href="https://support.3dverkstan.se/article/38-designing-for-3d-printing#:%7E:text=It%27s%20important%20that%20you%20use,printer%20will%20handle%20very%20nicely." rel="noreferrer">3DVerkstan</a></em></p>
<p>A chamfer, which normally is a 45° straight cut-off, doesn't create an overhang and, as such, prints better. If you still want a fillet, you could start with a chamfer of which you fillet the top, see the right part of the image above.</p>
<p>A chamfer with the height of the first and second layer is generally a good idea to reduce the slightly over “squished” first layer issues that create a lip around the base of the part.</p>

CC BY-SA 4.0
2022-06-04T18:19:46.007Z
The sag is not just "due to gravity". It would happen equally upside down or in zero gravity, because it's due to not having any surface to press the extruded material against. You only get the desired rectangular cross section of extrusion (e.g. 0.4 mm wide by 0.2 mm thick) when there's a surface to constrain where the material goes. Otherwise you get a roughly circular cross section whose Z dimension is greater than the layer height.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2022-06-04T06:32:16.600Z
2022-06-04T06:40:11.107Z
2022-06-04T06:40:11.107Z
0scar
<p>I am currently adding a fillet to the base of an object (the plane that's touching the bed) and I was curious if the radius of the filet contributed to any mis-prints. I've had luck so far but was wondering if the intensity of the radius had mattered.</p>
<p>I am using the Ender3 Pro.</p>
<hr />
<p><em>I may do some test prints and see for myself and provide an answer to share experience .</em></p>

<3d-design>
Can you fillet the base of an object without needing supports? Is there a recommended radius?
SeatbeltHands
# Can you fillet the base of an object without needing supports? Is there a recommended radius?

(Asked by: username_0 on 2022-06-03)

I am currently adding a fillet to the base of an object (the plane that's touching the bed) and I was curious if the radius of the filet contributed to any mis-prints. I've had luck so far but was wondering if the intensity of the radius had mattered.

I am using the Ender3 Pro.

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*I may do some test prints and see for myself and provide an answer to share experience .*

**Tags:** 3d-design


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## 2 answers

### Answer by username_2 on 2022-06-04. Score: 5 | Accepted answer

You can print a fillet without support as support material causes other issues like problems with removing supports and ugly scarring on you print. However, a fillet will cause an overhang when you slice the object

[![enter image description here](https://i.sstatic.net/mXpkz.png)](https://i.sstatic.net/mXpkz.png)

and may result into poor results as well, see e.g. this:

[![enter image description here](https://i.sstatic.net/hxKxd.png)](https://i.sstatic.net/hxKxd.png)

If your design allows it you should better use a chamfer than a fillet for the base of the print object.

A chamfer prints better than a fillet because a fillet creates an overhang (see indicated area on the left part of the image below.

[![enter image description here](https://i.sstatic.net/fiFxU.png)](https://i.sstatic.net/fiFxU.png)
*Image from [3DVerkstan](https://support.3dverkstan.se/article/38-designing-for-3d-printing#:%7E:text=It%27s%20important%20that%20you%20use,printer%20will%20handle%20very%20nicely.)*

A chamfer, which normally is a 45° straight cut-off, doesn't create an overhang and, as such, prints better. If you still want a fillet, you could start with a chamfer of which you fillet the top, see the right part of the image above.

A chamfer with the height of the first and second layer is generally a good idea to reduce the slightly over “squished” first layer issues that create a lip around the base of the part.

> **Comments:**
> **username_3**: The sag is not just "due to gravity". It would happen equally upside down or in zero gravity, because it's due to not having any surface to press the extruded material against. You only get the desired rectangular cross section of extrusion (e.g. 0.4 mm wide by 0.2 mm thick) when there's a surface to constrain where the material goes. Otherwise you get a roughly circular cross section whose Z dimension is greater than the layer height.  

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### Answer by username_1 on 2022-06-03. Score: 0

> wondering if the intensity of the radius had mattered.

Yes it does if it's an overhang.


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