CAD Model dimensions to layer thickness
I am trying to create a thin model with color four layers (for lettering cutouts) to create nametags (using onShape as the CAD program). I have the printing layer thickness set at 0.2 for all layers, including the base layer. I set color changes at 0.4, 0.8, and 1.2 on a 1.6 mm print. When I print the file I am only getting one layer of the base color. I have tried outputting from onShape in both 3mf and stl formats. STL seemed to work better but I still only get one base layer. Obviously I can tweak dimensions and experiment until I get the desired results but I am hoping that someone can explain why I don't get the expected results. for onShape users the model can be seen here. Printer Prusa Mini, Prusaslicer 2.5.
RE: CAD Model dimensions to layer thickness
Thats simple math I think. If you set a colour change at 0.4 then the second layer IS at 0.4 so will be a different colour to your first layer.
I take it you are getting 1 layer colour 1, 2 layers of colour 2, 2 layers of colour 3 and then the rest at colour 4.
Without a Prusa Slicer project file to see what you are working with its going to be hard to be certain.
RE: CAD Model dimensions to layer thickness
Is layer 1 not the base layer - is there a layer 0?
I assumed:
Layer 1 0.0-0.2
Layer 2 0.2-0.4
Layer 3 0.4-0.6 …
So a color change at 0.4 should have two layers. My goal is to coordinate the dimensions in the CAD and slicer data to that the letter cutout expose the appropriate colors. Here is the slicr file. Thanks very much for your response!
RE:
layer 1 extends from 0 to 0.2 and includes 0.2 I think. Layer 2 starts on top of that so i guess technically its 0.200001 to 0.4 etc. The layer 3 is 0.400001 to 0.6. Its all depends on where you expect a number range to start and end. IF you want to do this in your cad then try adding it so they end just in the outer boundary of your other layer.
Also no file attached. You have to ZIP up the saved 3mf file to attach it here. There forum is very limited in the file types allowed. It will just silently not attach it. And as the edit window is so short its always best to check your post after hitting save just to make sure 🙂
RE: CAD Model dimensions to layer thickness
Your explanation is correct (and helpful) but not quite complete. My dimensions aren't important in the CAD model, it is the slicer that is controlling the layer changes. As you say, the 2nd layer runs from 0.200…1 thru 0.4. If you set a layer thickness of 0.2 and a color change at 0.4 then the color change will begin at 0.200…1 so that the top surface at 0.4 will be the selected color. In the slicer you cannot set a color change at values that are not multiples of the layer height so if I want to print two layers of the base color I need to set my color change (in the slicer) at 0.6 so the new color will run from 0.400…1 thru 0.6. I had already set my layer cutouts in the CAD model at slightly less than the layer heights, but this didn't control the filament changes.
Again, to summarize, you must set the filament change one layer above the point where you actually want the color change to appear in the model. I had never printed colors where the exact level was critical so I had never understood how the dimensions would interact.
Thank you for your assistance. You set me on the path to thinking about this is a way that led me to understanding. I have attached the zipped 3mf file just to make the posts complete in case it helps someone in the future.