Hackaday - 3D Printering: Making a part in Solidworks
Brian has graciously allowed me to hop on the 3D Printering bandwagon to write a brief intro to the wonderful world of Solidworks. We’ll be making the same ‘thing’ as done in the previous ‘Making a Thing’ tutorials:
Admittedly, most Hackaday readers probably don’t have Solidworks as it is a very expensive program. The main reason we are posting this tutorial is so that you can understand the work flow and compare it to some of the free/open packages out there.
As Brian has touched on in his FreeCAD post, the part features of parametric models can be modified at any time. For example, let’s say I made a solid block, then added a specific size hole in the center of one face. Later, if I wanted to change the size or shape of the block, the hole would stay the same size and stay in the center of that face no matter the other changes to the object. See the graphic below, all that was changed was the size of the block, the hole stayed the same size and position (center of the face). This is different than if you were to ‘scale’ the entire object as the hole would also become stretched along with the block.
Here is a quick tutorial on 3d CAD in Solidworks.  While most readers don’t have access to it, these same ideas apply to many other cad programs.  The links above list tutorials in mostly free softwares.  123d Design from Autodesk is free and their Inventor program is freely available to anyone with a student email address through their student program, students.autodesk.com.  Another software that could be used for very quick and non technical parts is Tinkercad, it is web based and free.