Low- or No-Cost CAD (MCAD Modeling Column)31 Dec, 2007 By: IDSA ,Mike Hudspeth Cadalyst
These 2D and 3D modeling tools suit shoestring budgets — for work or for home.
When I was a kid, I built models all the time, and being a huge science fiction nut most of them were spaceships. After a while, I started to build my own designs, but I was always somewhat limited by the parts I could get or what I could make.
When I got a little older, my company jumped onto the 3D solid modeling bandwagon. I was hooked! I had access to a tool that would allow me to make my models any way I wanted, without physical limitations. The only problem was I only had so much time on the computer, and — go figure — the company wanted me to con-centrate on work-related activities. I needed something of my own.
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It was then that I started looking around for affordable modeling software that would run on my brand new 386 computer. I didn't find much, but eventually I found a program that said it could do what I was looking for. I spent way too much money for it — $399 — and tried to learn it. I never got anywhere. It was a disaster, but it taught me a few things about 3D modeling software, not the least of which was to look very carefully before I buy.
Nowadays, we designers have it so much better. The software has improved immeasurably, prices have come way down (even for the high-end stuff), and we have access to support channels like never before. It's a modeler's paradise! For next to nothing, we can access capabilities that were once only affordable to large multinational companies. Some of it is even free! Let's take a look at some of the tools you can acquire on a shoestring budget.
Figure 1. Draft IT has object snaps and dynamic dimensioning.
Many people are happy dealing in 2D geometry. Even a self-declared evangelist of 3D modeling like me has to admit that there is certainly a place for 2D work. But I couldn't call myself a decent 3D evangelist if I didn't point out that if your product occupies 3D space, your company would probably benefit from 3D modeling.
Siemens PLM Software (formerly UGS) has been working to get CAD users to transition from 2D to 3D. It has created many tools toward that end. One of its most interesting attempts has got to be the Solid Edge 2D product scheme. Declaring that 2D CAD is now a commodity item, it split off the drafting module and started giving it away scot-free! That's right, you can have just about the same level of 2D drafting software prowess as a several thousand–dollar seat of AutoCAD for nothing.
Another free 2D product is Draft IT from CADLogic, a British company. It's very straightforward, easy to use, and full of functionality. You just click and drag your entities, and dynamic dimensions rubberband out to let you know what you're doing. You have snaps (figure 1) that will ensure that your lines end where you intend. It's a relatively small download (37 MB) and runs very fast.
Figure 2. Inventor LT can import and export many software formats.
Of course, when you're ready to move to 3D, you have some great low- or no-cost options. Autodesk has an amazing free offer for Inventor LT. Inventor LT lets users create parametric models, translates a surprising number of standard modeling formats (something you usually have to upgrade for [figure 2, p. 37]), and creates production-ready drawings that are associative back to your model. It even has photorealistic capabilities. Now for the downside: It has no assembly capability. No sheet metal. No standard parts library. No available add-ons. And last, but not least, the license is good only for one year. Autodesk hopes you will like it enough at the end of your license agreement to buy it for somewhere in the neighborhood of $1,000.
Arguably the leader in the midrange 3D solid-modeling industry, SolidWorks presents SolidWorks Personal Edition. To download it online you need to sign up for a free seminar on 3D modeling, which is very valuable. You also can contact your SolidWorks reseller directly, and if you ask nicely they'll send you a CD. I like this approach because it nets you backup media. You get the basic core of the production version of SolidWorks on the CD, but it has restrictions. For example, you can't use it for commercial output; it has its own file format that cannot be opened by any other version of SolidWorks. The license will expire after 90 days, but you get the option to renew for free. It places a watermark on anything you print that clearly identifies it as the noncom-mercial version. You can't export to any other program, so the files you create will exist in SolidWorks PE pretty much forever.
Figure 3. This quad-bike design was the first-place winner in the Alibre Design Xpress contest. It was designed by Grant Marshall.
Alibre Design Xpress (figure 3) seems to have one of the best overall mixes of capabilities that I've seen so far. You can do parametric 3D design, assemblies (of as many as five parts), and even 2D drafting. It even provides user support! One of the nice things about Alibre is its built-in tutorial offering. The tutorials are the same as for the Professional (paid) version of the software, and they help you get up and running very quickly. If you register for Alibre Design Xpress, you get access to more functionality such as data exchange and the ability to create assemblies of as many as 10 parts.
For the nonhistory-based modelers among us, CoCreate's OneSpace Modeling Personal Edition (87 MB) lets you create great 3D models and 2D drawings (figure 4). You are limited to as many as 60 parts, which is the greatest number of any free application. Automatic feature recognition is a tremendous capability even for a paid program, much less for a free one. It lets designers use data from anywhere.
Figure 4. CoCreate OneSpace Modeling Personal Edition lets you build history-free models and then create drawings.
Not for Free
Of course, not all software is free. But some software is still an exceptional bargain, even if you have to pay for it. Take Caligari's trueSpace ($595, see figure 5). It might not really be considered CAD because drafting is basically nonexistent, but nonetheless it's good for modeling. trueSpace is a lot more freeform than any of the other programs I've discussed here. Designers start with a primitive form and push and pull it into whatever shape they want. You aren't going to find many programs in this price range that also do animations and rendering.
Figure 5. trueSpace has some amazing animation and rendering capabilities. It's not free, but it's not very expensive, relatively speaking.
And finally, Robert McNeel and Associates' Rhino ($995) is another program users can get into for free. Huh? You can download a fully functional version of the software and pay for it later when you want to use it commercially. It's used heavily in the industrial design community, and with good reason. Its capability is on par with the best out there in freeform modeling and rendering. It's a great way to start and a great tool for continued use. It's compatible with so many different file formats that some people use it simply as a translator.
Something for Nothing
Why do companies give away their software for free? They have several reasons. One is to make a splash, as Alibre did when it first released Alibre Design Xpress (back then it was called X CAD to heighten the mystery). Another reason is to gain market share. Companies also do it because they have other software they want you to buy, and the free stuff acts as a hook so they can reel you in. And then, most often companies want you to be able to learn how their software works so that when you upgrade to high-priced capability, you'll think of them first.
Mike Hudspeth, IDSA, is an industrial designer, artist, and author based in St. Louis, Missouri.