This week I tested out a joint design that I am hoping to use to connect the base to arm and arm to head of a lamp I am designing for light and interactivity. I decided to go with a dogbone design created to hide as much of the joint as possible. The vertical piece of wood slides into the base from the bottom using the weight of the base to hold everything in place. Miraculously, a tolerance of .01 ended up resulting in a very satisfying tension fit where the base needs to be pushed down with force onto the vertical piece but cant be pulled apart without lots of back and forth wiggling. The end result includes just a little bit of empty space at the side of the joint. In the next version, I want the outside edge of lamp arm to be flush with the base perimeter. I am planning on insetting the bottom of the arm and using the routing table to chamfer the edges of the arm so that it can slide in without having any empty space visible in the joint. Additionally, the joint is much larger than necessary. I designed this with a .25 inch bit but it can be reduced to a .125 inch bit with the dogbones smaller and closer together.

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This week I worked on insetting parts. I decided to go with a spiral which turned out to be a choice I regretted due to the time it takes to cut a spiral with a CNC. The path is almost as long as the full volume of a shape and you have to multiply that by two when you inset pieces.

I started off with vectorworks, creating a spiral, then I used the filet tool to expand the corners so that a .125 inch bit could fit into all the pathways. Next I offset the inner spiral .01 from the spiral channel as well as the outer circle .01 from the pvc circle that the “chip” gets inset into.

Next I had to do some sanding to get the acrylic with dichroic applied to it to match the height of the black acrylic that it is inlayed into as I forgot to account for the thickness of the film in my machine settings. Even if I did remember, it would have been quite a task to get it to line up exactly as I would have needed to use thicker black acrylic or take off some of the back of the acrylic with the film applied to it. I taped the dichroic spiral to the bottom of the pvc mount and sanded it down. Next I applied acrylic weld and found out that my tolerance of .01 was too high and there was a noticeable gap between the acrylic and dichroic. Luckily it is not visible when the “chip” is inset into the pvc base.