Multi part with multi color printing
Hi guys,
I hope I didn't miss any topic on this.
The idea is to split one into multi-part models so that I could use these parts to assign the extruders. During the modeling, all parts have the same coordinate origin (let me call this MCS). I'm exporting each slit model in a separate stl file. Today when I'm importing these files into to Prusa slicer all parts will be placed into to Prusa slicer origin.
Is there any way to tell Prusa slicer to use MCS of the models? If this is possible all sliced parts would align with each other in the Prusa slicer.
When these parts are aligned I would use these parts to assign the extruder to be used for the printing.
Secondly is there a setting to tell the slicer that when I'm changing the extruder to purge inside the model and not to use the tower?
Best Answer by JoanTabb:
Hello Romano,
I will use this model as an example 
First Select your preferred colours in Slicer, 
Then load the Green Body Part which will rest on the build plate.
then Right click on the model and choose 'Add Part Load'
then select an additional part and click enter
I Chose the black part of the eyes
These should appear, hung in space, relative to the body
then Right click on the model and choose 'Add Part Load' Again,
Then select an additional part and click enter.
I Chose the white part of the eyes and teeth
NOTE! the Pupils seem to have disappeared because everything is Green
Now in the right hand column of slicer click on the 'Extruder' option for each part, in turn, and choose relevant extruders
I chose to select the whites of the eyes so it would make the parts more obvious
Now select the extruders for the rest of the parts....
and now you should have a model ready to slice
NOTE this model has two models
so Add one of the parts of the candy, using the normal Add (Ctrl I) option, so that it's treated as a completely different item (Candy_1.STL)
Prusa slicer will add the new part, right in the middle of the build plate, under Omnom's Body
Drag the new part to where you want it, and then right click, add part (Candy_2.STL), and you should have all of the parts on the build table
Now you can choose the remaining colours
RE: Multi part with multi color printing
You export the model from your CAD as a multi part stl. So when loaded its a single stl with all the parts properly placed relative to each other. You can then use the Split to Parts button in PS. That will leave it as a single Object but allow you to assign the different parts to different extruders. Splitting to parts preserves the positions. Splitting to Objects makes them all completely separate so they will all fall down to the bed.
You cant preserve the design systems relative positioning on separate stl files. That was an often reported bug on really old versions of the software where it would place objects metres away from the build platter because the cad software happened to be set up like that. People couldn't see their imported files.
RE: Multi part with multi color printing
Splitting to Objects makes them all completely separate so they will all fall down to the bed.
May I add:
You can split them to Parts. They will stay within 1 merged object, and keep their positions
Now if your printer profile has more extruders, right click every single part and connect to extruder you want.
We will do what we have always done. We will find hope in the impossible.
RE: Multi part with multi color printing
Eef thats exactly what I pointed out in my post. Did you not read the sentence just before the one you quoted ? "Splitting to parts preserves the positions. Splitting to Objects makes them all completely separate so they will all fall down to the bed."
RE: Multi part with multi color printing
Is there any way to tell Prusa slicer to use MCS of the models? If this is possible all sliced parts would align with each other in the Prusa slicer.
As @Neophyl said: not possible.
But besides my remark above of keeping them as one merged object, there is a trick what can help:
In you CAD program also add a cube (may be small) besides the object you have. Place it (seen from above) to the north-west side of your object + bottom of cube is equal or lower then your object
After slicing in your CAD, export every part + that cube. So every single part has this cube in it.
Import them all into Prusaslicer.
Select them one by one and use the table in the right column to set all position to the same numbers (this is the corner of your cube).
When all are placed you can you the cutting tool to remove the cube. But ATTENTION: If not merged into one big object, all will fall on the plate!
In fact this trick is only useful to combine flat, on plate laying, parts.
Example: Text/logo on a flat object
Or : print something on top of an object you glued to the plate (be sure you know how to, because you don't want the extruder to crash into your object.
Have fun
We will do what we have always done. We will find hope in the impossible.
RE: Multi part with multi color printing
Eef thats exactly what I pointed out in my post. Did you not read the sentence just before the one you quoted ? "Splitting to parts preserves the positions. Splitting to Objects makes them all completely separate so they will all fall down to the bed."
Seems I overlooked that totally.
We will do what we have always done. We will find hope in the impossible.
RE:
Hello Romano,
I will use this model as an example
First Select your preferred colours in Slicer,
Then load the Green Body Part which will rest on the build plate.
then Right click on the model and choose 'Add Part Load'
then select an additional part and click enter
I Chose the black part of the eyes
These should appear, hung in space, relative to the body
then Right click on the model and choose 'Add Part Load' Again,
Then select an additional part and click enter.
I Chose the white part of the eyes and teeth
NOTE! the Pupils seem to have disappeared because everything is Green
Now in the right hand column of slicer click on the 'Extruder' option for each part, in turn, and choose relevant extruders
I chose to select the whites of the eyes so it would make the parts more obvious
Now select the extruders for the rest of the parts....
and now you should have a model ready to slice
NOTE this model has two models
so Add one of the parts of the candy, using the normal Add (Ctrl I) option, so that it's treated as a completely different item (Candy_1.STL)
Prusa slicer will add the new part, right in the middle of the build plate, under Omnom's Body
Drag the new part to where you want it, and then right click, add part (Candy_2.STL), and you should have all of the parts on the build table
Now you can choose the remaining colours
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Multi part with multi color printing
There are options to extrude waste into the model, But I don't use them. primarily because you also get a purge tower if there is ever more purge material than space available inside the model...
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Multi part with multi color printing
Hi guys,
Many thanks for your answers. Joan Tabb this was on the spot what I was looking for. Shame not to use the interior of the model for purging the material. I imagine that the first and last few layers would be an issue regarding the purging of the extruder.
Neophyl and Eef thanks for the good advice. Joan has given me the perfect way for my workflow.
Thanks