Editing 3D models, step format

[WillWelsh]

What is best practice for editing 3D models, typical .step format? I often download 3D files in step format from different places on the web. Sometimes I’d like to change some details, like moving a pin or adding a pin. I’ve tried Freecad 0.18 and the StepUp WB. The learning curve is steep, but I’m getting there a little bit day by day.
My last problem was a 3D model for a Wago PCB terminal block, 805-304. I can download the model from Wago in many different formats. So far I’ve tried step. But I’m not able to perform the changes I want to. Very possible because of my limited experience with 3d cad.
How do you guys work?

Thanks!

[eelik]

Adding features is easy because the step model can be handled as one of the objects when you create new details. Unfortunately many step models don’t have internal objects, it’s just one part, and removing details is difficult. There’s some workbench for FreeCAD to do that but as everything in FreeCAD, it’s difficult to learn. I tried once and gave up.

[maui]

@WillWelsh

Sometimes I’d like to change some details, like moving a pin or adding a pin.

for removing features you may try
https://www.freecadweb.org/wiki/Part_Defeaturing
Part WB is the easiest place to start in modelling.

[Piotr]

@maui

is the easiest place to start in modelling.

@maui I am some time behind @WillWelsh. I am finishing reading about selected FreeCAD workbenches and didn’t tried yet to design anything (even the one point). I planned to ask here in some time in future (after getting a little experience) but as the subject is on now…
I think WillWelsh mainly wont to modify the existing models and not only delete some parts of it or define the new model from beginning.
My, planed for future, question was: “Where to find the FreeCAD sources of KiCad models.” That is not STEP file, but FreeCAD original files with all steps on the way to get the model (at least for few of them). I planned to ask it after I will try to find them myself. But seeing this thread I am asking now (I’m not ready yet to start trying modifying so didn’t searched for sources).
The first what I plan to do is to modify 3D model: Diode_Bridge_Diotec_MicroDil_3.0x3.0x1.8mm to be the model of Vishay diode bridge B2S, B4S, B6S. There are many producers making diode bridges like B6S (to use them as second source). As I found no second source for Diotec MicroDil I used at my PCB Vishay B6S but didn’t found it in KiCad libraries so currently I have B6S footprint with MicroDil 3D

[Rene_Poschl]

The credits files in the 3d model repo should contain this information.
But generally: https://github.com/KiCad/kicad-packages3D-source and for the scripted models https://github.com/easyw/kicad-3d-models-in-freecad/tree/master/cadquery/FCAD_script_generator