Before you can make something you need a design. For some things, like your super secret cookie recipe, you can keep the design in your head. If you want to share designs or preserve them for posterity you need to document them in some way. While pencil and paper are still time honored tools for initial designs most makers eventually resort to Computer Aided Design (CAD) tools because they have a number of advantages:
- CAD designs fast and easy to modify once you learn how to use the CAD program
- CAD designs are easy to copy and share
- CAD designs are flexible
- They can be used to generate files that run CAM (computer aided manufacturing) systems to make physical parts with 3D printers or other CNC (computer numerically controlled) machines
- CAD designs can be used by structural, thermal, electrical, magnetic or other analysis programs for testing designs without having to build them first
- CAD designs can be used with rendering programs to produce photo realistic pictures of how objects will look before they are built.
Unfortunately there are some disadvantages to CAD that make it inconvenient for individuals to use:
- CAD programs can be difficult to learn
- CAD programs are usually expensive
- CAD programs can require expensive computers to run effectively
In the past few years there has been a lot of progress on eliminating some of these disadvantages. The following are some interesting free programs that offer useful CAD functions to makers on a budget. In most cases these programs are free with very limited restrictions on use and functionality.
Sketchup provides a free 3D CAD program that has a fairly intuitive interface and a fairly comprehensive set of features. A more capable paid Pro version is available but you can go a long way with the free version. I found this program easy to learn with lots of tutorial material and examples online.
OnShape is a cloud based CAD system currently in beta testing but they offer free accounts and it appears they will continue to offer free access after the beta test period. The major restriction on a free versus paid account is a limit on the number of private drawings you can have in their cloud storage. Currently, if you are willing to make all but five of your designs public you can use this software for free. It has much of the power of SolidWorks and it is being developed by a large group of former SolidWorks developers and employees. It runs in a browser as a service on a remote server so it will function on systems without expensive graphics systems since most of the processing is done in the cloud. However it will not function at all if you lack a decent internet connection. My initial experience with OnShape was very positive. It is not a particularly intuitive program for me but there are plenty of good tutorial videos. If you are familiar with Solid Works it is probably an easy learning curve. Even with no SolidWorks background and limited recent CAD experience I was able to do a lot in a short period by following tutorial videos. I’m not sure how convenient the cloud based model will be given the amount of time I spend in internet dead zones but the functionality is very impressive.
Autodesk Fusion 360: http://www.autodesk.com/products/fusion-360/overview
Fusion 360 is AutoDesk’s cloud based CAD but it can apparently be run without constant internet access. It also includes significant CAM (computer aided manufacturing) capabilities. I have downloaded but not explored this product. I plan to try it out to see how easy it is to fabricate a simple 3D printed object with it and will add to this review as I learn more about this product by using it.
If you are looking for free CAD I would suggest trying out one of the above tools. These are all proprietary software but they have capabilities far beyond the free open source CAD tools I am aware of. They also have a reasonable learning curve and lots of free tutorial information online. With products like these available for free registration there is little reason not to take advantage of the many benefits of CAD no matter how meager you design needs are.