Wednesday, 22 July 2015

FreeCAD: An Introductory Technical Guide

FreeCAD is an open source free software dedicated to 3D CAD modelling and is a great alternative to the otherwise commonly used commercial softwares like SolidWorks, AutoCAD, Creo or CATIA. It is a relatively lightweight but powerful Python code enabled component designing system, and certainly is one of the best open source tools any engineering student should learn to use.

General Information

  • Distribution Type: Open Source
  • Developed By: Juergen Riegel, Werner Mayer and Yorik van Havre
  • Reviewed Versions: 0.14(stable), 0.16 (beta development)
  • Available For: Windows, Linux(Ubuntu, Debian,Fedora), Mac OS X
  • Download Size: 202.2MB (Windows x64 0.15), 125MB (Mac OS X x64), 93MB (Ubuntu or Linux Mint x64)
  • FreeCAD Official Website

More about why you'd want to use it

  1. It's free. No issues of licensing, or getting college copies or, god forbid, pirated software.
  2. It supports all standard industry defined file formats including SVG, IGES, STEP and DXF. With the Teigha File Converter you can even manage your DWG formats too. Although I personally favour STEP.
  3. It's good for 2D drawing, but ideally awesome for 3D part designing.
  4. It has been designed to look and feel similar to the other CAD softwares, advantageous to people planning to switch over, in a week or so with a bit of practice you should feel right at home.
  5. It's got Python in it. Developers, feel something is off? Just use the interpreter to change it to exactly the way you want it. Incredibly powerful tool for the present "change-as-you-go" tech savvy peeps.
  6. Even if you don't know it, it's easy to learn. Also plenty of YouTube videos and a well constructed Wikipedia-style documentation have been provided. Read on for tips on starting up.

A Few Tips on Getting Started

Follow the installation guide, it really is simple and the best source. Especially Ubuntu and Linux Mint users, remember to add the PPA(freecad-stable or freecad-daily for the bleeding edge version) as mentioned in the Installation guide or else you won't automatically get your updates.

The Most Essential Parts of the Software:

Once you're done installing, the very first thing to get started is open a new document, and go to View>Workbench>Part Design or View>Workbench>Draft. These two workbenches are the quintessence of FreeCAD, and it may take a while to realize before you begin drawing random lines all over the canvas. Read about the Draft and Part Design workbench first, watch video or two and then you understand the methodology of design.

Started? A little more guidance here.

Here's where things begin getting a bit technical. Reader beware, a bit of familiarity with the software may be required beyond this point.

A. The Part Design Sketches

These sketches are essentially the way you create an outline in 2D for a 3D object. Create a shape with ease in the Sketch, dimension it, apply all the constraints you require (which by the way is such a great approach, since every assignment automatically will have to be defined to you through the constraints) and voilĂ , your design goes green and you've achieved a perfect shape. Now all you have to do is Pad it, Pocket it, Revolve it about the X,Y,or Z axes (which are the only options, you can move the part to the desired position later) and you have your perfect body shape. Also, save time and work with symmetries by mirroring your body.
Note: Often Pocketing might be an issue, with it not coming out right or asking for a face. Use the Part Design>Map sketch to face... option by first selecting the face you want to use, then using this option to assign a Sketch to a face. If it still doesn't work out well, ideally use the Boolean option in the next para on Part Workbench to achieve the desired result.

B. Once You Slowly Become an Intermediate User

You've played around with Part Design and realized almost all basic parts and components can be easily designed with this, but slowly when trying to assemble things, it becomes a lot trickier the more the number of parts you have. That's when the Part Workbench comes to the rescue. A few tools here are:
  • An incredibly powerful set of Boolean options that let you combine various parts to for a fused solids, or subtract one solid from another to modify that elusive curved surface Part Design didn't allow you to create a sketch on.
  • Extruding, filleting, chamfers and the works. All here.
  • A quick "smart dimension" like option to measure your work, although you might still have to use the Draft>Dimensions tool to satisfy your stern pedagogical professors.

A Few Final Parting Words

  • Earlier versions of FreeCAD were a little buggy, with it shutting down sometimes randomly while performing an operation, opening a sketch or pressing the Delete button. So it's a good idea to follow the practice of saving your work constantly, at each step.
  • If you're having a hard time modifying a part, or making strange projections, analyze the method you are using, because iffy methods are bound to throw errors later on. In this aspect, FreeCAD is brilliant, it makes you think about the optimal method to easily design a part. No shoddy work there.
  • Companies are dying for people who can design elegant parts. So without spending the $3995 premium on a copy of pro SolidWorks (or some such figure, just quoting a chap) if you can do the same work, you're going to be an obvious choice for any company.
  • Once you've begun, join the GrabCAD community and share your work proudly for all to see! (Please do remember to export it as a STEP file so others can download and use it.

Hope you enjoyed the article. Any suggestions, appreciation, comments, hate remarks (hopefully none) do jot them down below.