Trestle Table – Playing With Curves

Article - September 17, 2010

So today I started to take my trestle table from a small sketch to………wait for it……. A BIG SKETCH! Yeah not super exciting but its a great opportunity to show the details of a very non-scientific part of my process. With so many curved lines at play, this is not something I can model up in StetchUp very effectively. So its pencil and paper all the way. You can see with the image on the left that I had several ideas to play with. Those are just two. But the bottom left version is pretty darn close to what I’m aiming for at this point. Obviously this is going to be an exercise in making one piece flow smoothly into the next. No abrupt changes anywhere. But before I can even think about making this thing a reality, I need to make a full-sized drawing. That’s where I’ll hammer out much of the detail.

I started by sketching the basic shape and including my best guesses on the angles and widths. The angle I liked the best (for the vertical pieces) turned out to be 80 degrees. The next order of business was to start “roughing in” the curves. This is something I like to do completely by eye, using my original miniature sketch for reference. I make wide pencil strokes back and forth and essentially scribble the curve in place just as a basic starting point. I will step back every few seconds and even screw up my vision to get a better feel for the flow of the piece. Not sure if anyone else does that, but sometimes, a set of curves is hard for me to judge when looking at it with absolute clear vision. So I actually go just slightly cross-eyed, intentionally, to create a blurry view. And oddly enough, I tend to see things that my clear vision doesn’t allow me to see. Is that weird? It sure sounds weird to say it.

Well anyway, once the curves are roughed in, I’ll go back with my French curves to see if I can match them up with my existing scribbles. The French curve produces beautiful asymmetric curves, so if I can get a close approximation to what I drew by hand, I will simply trace a nice clean line right over my scribble. Then I go back and remove the scribble with an eraser.

The basic structure and curves are now in place and its time for the fun/hard part. You have to decide if you like what you see, and if not, figure out how to fix it. So I tinkered with some more ornate feet, which ultimately looked too busy and bulbous. That then led me to thin out the foot for a more delicate look. Now we’re on the right track! I started to trim things back all over at this point, including the top and the vertical support. All in all, the more slender look put a smile on my face. The shape is beginning to look like something out of nature with a dash of whimsy, which is exactly what I’m going for.

Now the next step was to begin thinking about how this form would come to be from actual square pieces of wood. I will most likely use 8/4 stock for the top and bottom supports, with 6/4 stock on the vertical pieces. So my goal is to not only blend the vertical pieces to the top and bottom with respect to the curves, I also want to blend them in terms of thickness. The Sketchup image below gives you an idea of what the rough pieces might look like before blending. Also, I should note that the joinery connecting everything together will be a mortise and tenon. I may even use the Domino to make my life easier. You’ll notice in the final picture below that I quickly sketched in the potential locations for the two cross-members. I’ll worry about those tomorrow.

I can’t even begin to describe to you how subjective this part of the process is. As woodworkers, there are some things that we will almost universally agree look “off”. And there are surely things that we will all agree look “just right”. But everything else fits into that gray area, where its simply an expression of our personal taste. So don’t be too hard on yourself at this point. Its not easy going from a blank sheet of paper to an actual project. And don’t worry so much about making mistakes, that’s what erasers are for. I stared at the sketch for hours today, trying different curves, different feet, different thicknesses, and it was pretty clear that there would never be one right answer. I have a few more ideas and I really want to let this particular design “rest” overnight. Tomorrow I’ll look at it again with a fresh set of eyes and perhaps I’ll see something that wasn’t evident the day before. The next step will be to cut out my templates and make a prototype. I need to see this bad boy in 3D before going any further. And at some point here, I need to break out the video camera and start filming this episode. Wish me luck!

Recently I mentioned that this project might be a good candidate for a “design by committee” experiment. Well, once I started getting into the details with all the curves, I realized its actually a terrible candidate. If we attempt something like that in the future, its going to be on a project that’s a little more straight forward, not only in design but also function. I think I confused some people by calling it a gaming desk, when what I had in mind the whole time was a trestle table with no fancy storage. So we’ll do something like that soon, just not on this project.