converting STL files into STEP files (thingyverse to CAD)

[limor]

I wanted to modify (adapt it for smaller size robots) the Inmoov hand published on thingyverse



I've spent hours trying to find a way to convert STL files into something that CAD system such as Inventor and FreeCad can import.

The problem is that STL is a mesh file and CAD systems work with "bodies" and convex objects and keep data in a way that is easy to define transition between 2D sketches and 3D convex objects and ways of mutating bodies etc.

Finally I found a way. The software is called Instep
http://www.solveering.com/products/prod ... 2step.html

Step1 : import all STL files into sketchup and create a single STL file with all the objects (move each one around when importing so that they don't overlap)


Step2 : import the new file into InStep
It will automatically recognize every independent object and treat it as a solid. in this case 61 solids were found.


Step3 : change the settings in InStep to export all objects


Step4 : export as STEP file and read it into your favorite CAD.
As you can see, there are 61 bodies detected.

[limor]

While importing the STEP file into FreeCAD took only about 2 minutes, when trying to import the STEP file in to Autodesk Inventor, it took over 2 hours and froze my i3 8gb laptop. The resulting part file was 200mb which is pretty much unusable.

[ the output STL file from sketchup was 7282kb, the output STEP file from InStep was 150mb . in their documentation they ]

I'm going to try and reduce the number of polygons (150k) using meshlab and rund the process again to see if it creates a decent size STEP file.