Hi,
My H2D is impressively, reliably, repeatably accurate dimensionally.
So, I was confused when some precision threaded parts I designed with complex surface geometry were suffering from lack of proper fit - and upon careful measuring, I found the parts measurements to be significantly deviant from the CAD measurements. The shape of the parts and features were fine, the surface quality was excellent, but the dimensions were off.
The stranger thing was that parts with similar features were VERY accurately printed, dimensionally. Due to this, and from experience with the inadequacies of triangulated surface model formats (like the notorious and unfortunately ubiquitous STL format), I decided to check the dimensions of the STL models versus the designed CAD dimensions.
It turns out that in the case of the parts that seemingly printed with incorrect dimensions, they actually printed on the H2D with outstanding accuracy - that is, exactly according to the (wrong) dimensions of the STL model file itself!
Resizing the STL files to the proper dimensions in a 3rd-party slicer I’ve found to be very accurate and saving the resulting dimensionally-corrected model, resulted in perfect prints of the correct dimensions.
Exporting the file in STP (STEP) format will not cure this particular problem in most cases, because assuming the STEP file contains the correct representation of the model (which is not always the case either), the conversion to STL will show the same problem (and Bambu Studio converts the STP file to STL as can be seen when BS executes the ‘repair’ function on Windows computers by invoking the Microsoft 3DBuilder to do it.)
Bottom line: it seems prudent to always verify that the dimensions of your STL/STP models are correct and resize the model if needed, before printing.