Week 6: Computer-Controlled Machining

Designing the table

I wanted to design a table that would fit in the corner of my room to support my minifridge. I used Fusion360 to design my table, creating sketches for the top and legs, creating bodies, creating components, and assembling the components to ensure that the parts would properly fit together.

I created a .dxf file with all my sketches laid out within a 4'x8' sheet to make sure that I could properly machine my parts. My initial table design would not fit within the 4'x8' rectangle, but since I made my design (mostly) parametric, it was easy to rescale the table.

Cutting the parts

I took my .dxf file to the arch shop where I got help importing it into Mastercam and creating toolpaths. I ended up using three different toolpaths to (1) drill holes at all the interior corner points to ensure a square corner, (2) use a smaller bit to route the small cutouts on the table top, and (3) use a larger bit to route the longer edges. Since my design was press-fit, it was important to drill out the holes since there is no way the router bit can carve out a square.

I was using the Onsrud in the N51 woodshop to cut my parts. To use it, I secured the OSB to the bed and activated the vacuum seal. I loaded the machine computer with the gcode from Mastercam and started the job.

The z-depth specified on the computer left a bit of an "onion-skin" so we had to go in with utility knives to cut the pieces off of the bed. Thanks to Kellie and Anthony for helping me cut off my pieces!

Assembling the table

Once my pieces were freed, I had some work to sand down the parts and actually assemble the table. I used a metal file and sander to break off the onion skin and sand down the edges.

Once the legs were smooth, I attached them together to test my press-fit.

Then, I attached the table and carefully carried back to my dorm. I used a bit of wood glue to add some more stability. I haven't actually placed my minifridge on top yet because I want to finish the top so that a leaking minifridge won't damage the table, so I'll update when I have some time to add a coat of polyurethane and actually put my fridge on top.