Computer Controlled Cutting

This week I decided to make a press-fit tree construction kit. Although I have some experience with Rhino (which I used for last week's assignment), I've never used SolidWorks. SolidWorks seemed like the right choice for this assignment because I needed to think about material thickness and possibly make adjustments around that variable. Two of the features of SolidWorks that I used this week were Equations (combined with the Smart Dimensions tool), and the Assembly view.

Thinking parametrically in design was a new concept for me, especially coming from Rhino, where I have taken a more free-form approach to modeling. I found parametric design both liberating and tedious. Liberating in the sense that I could have some confidence that my pieces would fit together, and tedious because it took more planning and forethought than I am used to. All in all, it was a great exercise for me, and I was so thankful for all of that work when I cut the pieces on the lasercutter and everything fit together right away! And I knew that if it didn't work, I could make simple changes to fix it.

I used several equations in my design:

• "materialThickness" = .165in
• "slotWidth" = "materialThickness" - 2 * .007in - .006in (taking into account the kerf and offset)
• "tabWidth" = "materialThickness"
• "treeRadius" = 2in
• "treeTopHeight" = 3in

Once I had modeled all of the pieces in separate files, I brought them all together in one assembly. Once they were in the assembly, I mated some of the sides together, and when they all merged together into one central unit, it was pretty exciting.

The parametric design actually freed me up to be creative when I got to the lasercutter. Since I knew the hole size for the trunk of the tree to fit into the treetop was accurate, I was able to create new treetop shapes - squares, diamonds, ovals, etc. on the fly and know that they would integrate with the rest of my construction kit. My settings gave the pieces a tight fit, but for my purposes it worked well because I needed the pieces to stay up by themselves on the tree trunk.