Prusa Slicer  

RE: Prusa Slicer

Your CAD file 3mf is not the same as a Prusa Slicer 3mf.  3MF is just the container.  Just because your CAD 3mf might have an internal setting for units are in X does not mean that PS knows about it.  Basically the only data it uses from your 3mf is the geometry data. If you happen to have material, colour, or anything else specific to your CAD package then it will ignore that as well.  PS doesn't know about any of that as the tags within a 3mf file are not defined and there is no 'standard'.  Every software coder is free to use however they like beyond a certain basic format.  It is why even though Bambu slicer is forked from PS they broke compatibility awhile back between their 3mf files and prusa slicers (not sure if its fixed now). 
Everything PS imports is assumed to be metric, ie in mm.  Just because you may have the Inches tickbox ticked does not change that part of PS.  That is just a setting for 'I want to display stuff in inches'.

There is no setting for 'assume everything I import is in inches'.  PS will ask when you load an object if it is very small as a sort of sanity check and give you the option to treat it as inches but beyond that you can either manually scale or use the right click and convert to imperial units which will then assume that Object is in inches instead of mm and scale it as such.

Btw we have a specific Prusa Slicer section to the forum if you look towards the bottom.

RE:

As Neophyl said. 3MF is not nearly as standard as you might imagine. It's basically just a container format, but its components may vary significantly from vendor to vendor. In your case this seems like an obvious mm vs inch mismatch between what Prusaslicer expects and what your CAD software exports. I bet if you export in mm, the import will be fine.

RE: Prusa Slicer

Thank you to both of you for your feedback. 

RE: Prusa Slicer

Good day all, 

First and foremost; I have been using CAD since 2003 and 3D printing since 2010. I began with AutoCad in college and transferred to Turbocad Platinum after then. Regarding the 3D printer world, I began with the Ender 3 in 2015 before migrating to the MK3S+ in 2020. To be clear my experience is plentiful in the CAD world but not so much in the 3D file world. Lastly on the education/experience front, I have taken and completed the short educational eBooks from Pursa cpm mod

 

Now on to the problem. This problem is universal across every print which leads me to believe that it is a simple setting; I'm just not sure where the setting issue is. Both the slicer and the CAD are set in inches.

 

After I'm finished with a design in CAD, I save the file in 3MF for printing. When I import the file into the slicer it always populates the same way; at a scale of less than a 1/4 of an inch. In other words I always have to scale it up. Now if I save in STL or other file extensions, I do not have this problem but of course have some others that were discussed in the eBooks. 

 

Can someone point me in the right direction?

It sounds like you've got a solid background in CAD and 3D printing! The issue you’re experiencing with the 3MF files might stem from how the slicer interprets the units. Even though both your CAD software and slicer are set to inches, some slicers can misinterpret the scale of 3MF files.

Here are a few suggestions:

Check Slicer Settings: Ensure that your slicer is set to recognize the units of the imported file correctly. Sometimes, it may have a default unit setting that doesn’t match your CAD software.

Exporting Settings: When saving your 3MF files, double-check if there’s an option to specify units during export.

Test with Different Software: If you haven't already, try opening the 3MF file in another slicer to see if it scales correctly. This can help pinpoint if it's a slicer-specific issue.

Contact Support: Since you've completed the Prusa eBooks, reaching out to their support can provide tailored assistance based on your workflow.

Hopefully, one of these steps helps resolve the scaling issue!

Best of luck!