How to change extruder only for top layer?
 
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How to change extruder only for top layer?  

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mhacker
(@mhacker)
Trusted Member
How to change extruder only for top layer?

I have a sign where I want the top layer to be printed with a different extruder. Using the multimaterial painting tool results in the color going several layers down which I don't want, I simply want the top layer and nothing else.

When I choose the option to change extruder on the layer view (right-click on slider), it works fine on the second to top layer - I can see the purge tower generated and all. But when I choose the last layer it does not appear to do anything (and once or twice I've seen a warning that there are tool changes that will not be executed since they are after the end of the gcode).

How can I achieve this?

This topic was modified 4 weeks ago by mhacker
Posted : 15/05/2025 12:43 pm
Neophyl
(@neophyl)
Illustrious Member
RE: How to change extruder only for top layer?

You dont use that method on multi extruder prints.  Thats for single extruder with filament changes.

When you select the Paint tool one of the Tool options is 'paint within height range' (at least in 2.9.2).  Seelct that and type in the height of the range you want to start at.  You can paint as many ranges as you like.

You can use that to define your different colour/extruder for painting.  Have a look at the attached zipped project file.

Other options is to split your raised areas to a different Part of a multipart Object and then you can simply assign a different extruder to the second Part.

You can also apply a normal Height range modifier and assign a different extruder to that.  The example also has that option demonstrated.  

Posted : 15/05/2025 1:00 pm
mhacker
(@mhacker)
Trusted Member
Topic starter answered:
RE: How to change extruder only for top layer?

The height range modifier trick works great, thanks! I'll use that. 

See the attached file for a demonstration of the multimaterial painting issue. Here I tried to only paint the top 0.1 mm with extruder 2, but still the extruder gets used on the top three layers.

Posted : 15/05/2025 2:34 pm
Neophyl
(@neophyl)
Illustrious Member
RE: How to change extruder only for top layer?

Change your layer height to 0.1 and your painting on your project works.  Its because the painted area spans multiple layers so it colours the layers above and the layer below.  Remember you are quantizing the object into discrete levels and you painted part of the object that is on both sides of a layer boundary.

Posted : 15/05/2025 3:45 pm
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