This is an example of an assembly that was created with FreeCAD. It is a complete Stirling Engine.
All parts were created in one file from machining drawings, found on-line, basically in the order of assembly sequence.
All fasteners complete with accurate threading were imported from McMaster Carr STEP files.
The file is 3.84 MB, mostly due to the fasteners.
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Created on Windows 7 V0.13 Rev 1828