Playing with Blender For Artists (Bforartists) - Easier way to learn Blender?

[sorveltaja]

After taking closer look at the bones system, objects are linked to bones, so they just follow their parents. It appears that there doesn't need to be surface reaction related factors involved. Also it seems to provide more accurate movements, when compared to rigid bodies, where there may be some lag between objects.

Although it's very 'clean' way to make objects move, I find rigid body simulation more tempting at this point.

An example, where rotating purple frame is the animated object:

3D files (STL) and instructions for the mechanism that I used, are available at https://www.instructables.com/Antikythera-Orrery-3d-Printed/

[sorveltaja]

I've experimented a bit with rebuilding meshes in Blender, as imported ones are not necessarily that easy to edit.  For example, selecting vertex/edge/face loops or rings is usually impossible with such objects.

Comparison of imported mesh object (2800 vertices) vs rebuilt one (360 vertices):

 [ You are not allowed to view attachments ]  

Imported objects appear to have their origin points at 0,0,0 location (yellow dot on the left):

  [ You are not allowed to view attachments ]  
   
One way to set object's origin or pivot point to a desired location is to select a set of vertices/edges/faces in edit mode.  3D cursor (which acts as a temporary reference point) is then moved to the center/middle of those elements by Shift S → cursor to selected.

Next in the object mode right-click → set origin → origin to 3D cursor:

 [ You are not allowed to view attachments ]     

Some parts of imported mesh may not have so regular structure, though:

  [ You are not allowed to view attachments ]  
                                    
In this case, another way is to use a circular primitive object like UV sphere, which is scaled and moved to find approximate center point:

 [ You are not allowed to view attachments ]