From 2D AutoCAD to 3D SketchUp-It Doesn’t Have to Hurt

I received an e-mail last week from a reader who feels that he is being “forced” to move from AutoCAD to SketchUp, and he isn’t a happy CADer. I can relate. I first learned to make design drawings with pencil on paper many years ago. Eventually I made the move to AutoCAD, and bit the bullet a couple of times when a new computer or new software release meant I had to shell out a bunch of money to replace software that met my needs and worked just fine. I don’t use AutoCAD very often these days, so I moved back from the big boy version to LT, and I keep an old machine on life support for when I do need AutoCAD.

I’m sold on using SketchUp for the things I do on a regular basis. Most of that is furniture design and making detailed drawings of furniture and cabinets for publication. Last summer I co-wrote (with Glen HueyFurniture in the Southern Style and all of the illustrations came from SketchUp models. The format is similar to my first book Shop Drawings for Craftsman Furniture, and my other books of measured drawings. All of the illustrations in the earlier books began life as CAD drawings, so the differences between AutoCAD and SketchUp have been on my mind lately. The last book was faster to produce, with more accurate results, and more options for what eventually appeared in print than the first one, thanks to SketchUp.

I picked up on using SketchUp in a relatively short period of time, but one of the things that held me back was my expectation that SketchUp would behave like AutoCAD did. Like my irate reader, I thought SketchUp looked too cartoony, and that the interface had been simplified to the point that I couldn’t do serious and accurate work. What I finally figured out is that the simplicity of SketchUp is elegant and efficient. Most of the problems I had were complications I tried to introduce based on my past experience. I wasn’t catching on because using SketchUp was easier than AutoCAD. I kept getting surprised when I found out that an operation I expected to take four or five steps to complete took one or two. Today, when I go back to use AutoCAD I find myself annoyed at how many times I need to hit “Enter”, and how slow and inefficient my work is compared to when I use SketchUp.

The great leap forward for me came when I switched my focus from the finished drawing to building the model. Two dimensional CAD is essentially an efficient version of conventional drafting-it is an interpretation and representation of a physical object. When you learn mechanical drawing, you learn a language that allows you to communicate the details of a physical object.The problem is that any form of drawing, from a napkin-sketch to a set of CAD-generated blueprints, forces you to worry as much about what the drawing looks like as the physical properties of the object.

Three-dimensional modeling is far more direct, if you focus first on making a good model, then extract the two dimensional information you need from the model. You don’t spend time mentally translating because the language of SketchUp is closer to the language of building-this goes here, that goes there and this other piece goes in between. Do that one time in SketchUp, and you don’t spend any time worrying about whether or not the plan, elevation and section agree. Change the object and all the views change with it. Best of all, you don’t need to visualize what the relationship between parts will look like in three dimensions, based on different orthographic views, you can spin the thing around and look at it from any angle or distance you want.

If you’re struggling with learning SketchUp, step back and look for the reasons why. Part of the learning curve is developing hand/eye coordination that’s different from what you’re used to, especially if you’re experienced with mechanical drawing or conventional CAD programs. The other part is learning the language that SketchUp speaks. Shouting at SketchUp in AutoCAD language doesn’t do you any good, even if you shout really loud.

–Bob Lang

I teach SketchUp, here is the current schedule or e-mail to schedule a class

I also wrote a book to help woodworker’s learn how to use SketchUp. Find out about Woodworker’s Guide to SketchUp

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