For this week’s assignment, I built a CNC Zen garden. Our lab’s ShopBot dust collector accumulates tons of sawdust each week, so I thought it would be interesting to create a project that does something with this refuse material.

I created the pattern in Inkscape, using Extensions> Render> Spirograph.

I used Part Works to set up my file to run on the ShopBot CNC Router.  Most of the input values are inconsequential since I ran the machine with the spindle off, but I did set my tool diameter to .25 inch, feed rate to 102 ipm, and plunge rate to 30 ipm.

 

Spirograph pattern file available here

 

I made a simple box to contain the garden. My strategy was to use finger joints to join the parts together. I did have to add notches to the corners since the diameter of the tool would naturally create rounded corners, making it difficult to fit the corresponding pieces together.

Shopbot file available here

Settings:

Bit: .125" endmill; Pass Depth: .1"; Spindle Speed: 12,000 RPM; Feed Rate: 1.7 IPS; Plunge Rate:0.5 IPS; Stepover: 40%

Applications

I thought it might be interesting to somehow capture the pattern once it is made. I could see this as a way to turn sawdust into wood composite panels. I tried a few experiments, mixing sawdust with a binding agent. So far, no luck- the pattern looks awful when cut into a damp mixture.