<p>The size of the nozzle usually isn't the main factor for how close you can put nozzles together.  To keep the filament drive gear system from being the limiting factor, you would need Bowden extruders. &quot;Then, the heat sinks and fans would be your limiting factor.  Have you considered a single nozzle with three extruders?  Otherwise, you need custom angled heat sinks similar to the three heat sinks on a single nozzle, and still a way to orient the nozzles at the same Z-height.  That would be difficult if all the nozzles are on the same heater block.  It still seems that nozzle size is the least of the issues of putting nozzles close together.</p>
<p>If you search for smaller nozzle sizes, you will get nozzles with smaller openings, not smaller overall size.  The threads on the nozzles are a standard size.  Thus, the smaller opening size can't be put closer together than the larger opening size.  Otherwise, you have only small variations between different types of nozzles and need room to screw them in to the heater block if you put all of them into one block.  You can get a nozzle using a 6 mm hex wrench that is smaller than one using a 7 mm hex (E3D).</p>

CC BY-SA 4.0
2020-07-06T19:10:21.857Z
2020-07-07T19:23:42.037Z
2020-07-07T19:23:42.037Z
Perry Webb
<p>One of the thinnest hotends I've seen are those from a Chinese factory Mellow Store, the heatsink is smaller than the top flange to mount the hotend. I don't know the quality of these hotends, the image below shows the basic layouts of available options:</p>
<p><a href="https://i.sstatic.net/MsvUL.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MsvUL.jpg" alt="Mellow Store custom hotend" /></a></p>
<p>Ultimaker uses high quality hotends which are pretty small 2.85  mm hotends they call &quot;cores&quot;, they house 2 next to each other and use a lifting mechanism:</p>
<p><a href="https://i.sstatic.net/pl0mt.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/pl0mt.png" alt="Ultimaker 0.8 mm core" /></a></p>

CC BY-SA 4.0
2020-07-06T19:50:00.283Z
2020-07-07T07:20:35.680Z
2020-07-07T07:20:35.680Z
0scar
<p>I have a few 3D printers and now want to start building a custom 3D printer.
I want to build a 3D printer with multiple nozzles, and I want to make the hotend thin so the nozzles can be closer together.
What is the thinnest nozzle avalible to buy?
Are there any guides or details on how I could make a custom nozzle or modify a nozzle if I can't buy a thin nozzle?</p>

CC BY-SA 4.0
2020-07-04T07:03:08.647Z
How many nozzles? Do you need a lifting device? Multiple nozzles at the same height is not easy to align and can easily tip over you print during printing. There are also multiple in, one out hotends.
0scar
CC BY-SA 4.0
2020-07-04T10:22:53.670Z
what is the "thinnest nozzle" in this regard? Would you fo so far as to machine a custom part?
Trish
CC BY-SA 4.0
2020-07-04T11:51:56.177Z
@0scar I've had issues with mutliple nozzles not being at the same height. Planing to set them up so they can move independently.
user802599
CC BY-SA 4.0
2020-07-04T12:06:03.890Z
@Trish I would probably test with 3D pen nozzles first if I can't find a thin 3D printer nozzle. I don't have the tools to machine it myself, but would like to get something custom made once I have the design and software working.
user802599
<hotend>
What is the thinnest hotend?
user802599
# What is the thinnest hotend?

(Asked by: username_0 on 2020-07-03)

I have a few 3D printers and now want to start building a custom 3D printer.
I want to build a 3D printer with multiple nozzles, and I want to make the hotend thin so the nozzles can be closer together.
What is the thinnest nozzle avalible to buy?
Are there any guides or details on how I could make a custom nozzle or modify a nozzle if I can't buy a thin nozzle?

**Tags:** hotend
> **Comments:**
> **username_1**: How many nozzles? Do you need a lifting device? Multiple nozzles at the same height is not easy to align and can easily tip over you print during printing. There are also multiple in, one out hotends.  
> **username_2**: what is the "thinnest nozzle" in this regard? Would you fo so far as to machine a custom part?  
> **username_0**: @0scar I've had issues with mutliple nozzles not being at the same height. Planing to set them up so they can move independently.  
> **username_0**: @Trish I would probably test with 3D pen nozzles first if I can't find a thin 3D printer nozzle. I don't have the tools to machine it myself, but would like to get something custom made once I have the design and software working.  

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## 2 answers

### Answer by username_3 on 2020-07-06. Score: 1

The size of the nozzle usually isn't the main factor for how close you can put nozzles together. To keep the filament drive gear system from being the limiting factor, you would need Bowden extruders. "Then, the heat sinks and fans would be your limiting factor. Have you considered a single nozzle with three extruders? Otherwise, you need custom angled heat sinks similar to the three heat sinks on a single nozzle, and still a way to orient the nozzles at the same Z-height. That would be difficult if all the nozzles are on the same heater block. It still seems that nozzle size is the least of the issues of putting nozzles close together.

If you search for smaller nozzle sizes, you will get nozzles with smaller openings, not smaller overall size. The threads on the nozzles are a standard size. Thus, the smaller opening size can't be put closer together than the larger opening size. Otherwise, you have only small variations between different types of nozzles and need room to screw them in to the heater block if you put all of them into one block. You can get a nozzle using a 6 mm hex wrench that is smaller than one using a 7 mm hex (E3D).


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### Answer by username_1 on 2020-07-06. Score: 1

One of the thinnest hotends I've seen are those from a Chinese factory Mellow Store, the heatsink is smaller than the top flange to mount the hotend. I don't know the quality of these hotends, the image below shows the basic layouts of available options:

[![Mellow Store custom hotend](https://i.sstatic.net/MsvUL.jpg)](https://i.sstatic.net/MsvUL.jpg)

Ultimaker uses high quality hotends which are pretty small 2.85  mm hotends they call "cores", they house 2 next to each other and use a lifting mechanism:

[![Ultimaker 0.8 mm core](https://i.sstatic.net/pl0mt.png)](https://i.sstatic.net/pl0mt.png)


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