Step 1: Modeling in AutoCAD
I modeled the shelves in AutoCAD by drawing the shapes in 2D, extruding them into 3D and subtracting the inner volumes. The final shelves will be made from 3/4" plywood, with each unit piece measuring 9" inner diameter and 10.5" outer diameter. The depth of the shelves will be 15". For now I've only built a prototype set which has been scaled down by 1/3 and cut from 1/4" plywood. I exported these shapes from AutoCAD as a single stl file to send to 123D Make.
I've attached the dwg and stl files for both the full sized and scaled versions of my tetris shelves.
Step 2: Send to 123D Make
In 123D Make, I set the joint type to finger joint with 12 fingers for each joint. I specified the dimensions of my material and 123D Make created 2D vector files with the correct finger size and fit them onto sheets for laser cutting.
Step 3: Cut and assemble pieces
I removed all the pieces and inspected the edges, some needed additional sanding/finishing. I separated the pieces by size (there are 6 different lengths) and compared them to my 123D Make model. To be safe, I assembled my tetris pieces without glue first.