Creating a Design: #

For this week’s assignment to “make something big,” the first item that came to mind was a replacement shelf for one in my kitchen that broke earlier this summer. After a conversation with my housemate about this idea, he mentioned a tool called MakerCase. This is a nifty online tool that produces 3d designs for boxes that can be assembled using finger joints. Based on the available space, I am hoping to create replacement cabinet that has 5 shelves, and that is 76" tall, 33n wide, and 13" deep. I want to have a finger size of roughly 5.065, along with 1 row, and 5 columns. This will allow me to have fewer finger joints and will hopefully make the assembly easier. Based on measurements from students this past weekend, I am making setting the material thickness to 0.435 inches.

Click to download initial Makercase Design

With a DXF file from Makercase, I opened up the design in Fusion. From here, I added additional finger joints to the back of each shelf, I added holes on each wall of the shelf to hold a wooden dowel, and I increased the overall height so that the top should have an edge to it. I also added points to every inside corner to account to create dogbones, and I arranged the panels so that they were laid out on two side-by-side 48" x 96" sheets.

CNC Machine Tutorial: #

The CNC tutorial this week was rather brief and involved a test design. We walked through the process - which mostly involved Chris modifying the files on Mastercam - then plug a USB into the CNC machine, selected the Gcode, and ran the machine.

• 1/4 bit for large paths
• 1/8 for smaller piece and for holes
• OSB has smooth and rough side

The CNC Machining Process #

After sending the modified DXF files to Chris, I went to the architecture shop at N51. We spent about 30 min resolving minors issues on the Mastercam software, like deleting a few lines, and reselecting lines and points. I’ll be honest that other than watching what Chris was doing, which seemed to involve creating the correct paths and exporting the Gcode file, I’m not really sure the software actually works. I’m not sure if this was true for all sections, but the jist of this week felt like “make a design and send it to Chris.”

The first sheet ran successfully, but I ran into issues with the second sheet. We thought that the machine was not registering the design, however, after the second attempt at remilling, we realized that a bit had broken. Chris installed a new bit and we re-ran the file. This time it was successul. The only cavet was that because we were running just part of the design and because the bit had broken mid-milling, some of the “onion skins” were closer to squash skins. They were about 1/8" thick and required a jigsaw to cut them out.

While the CNC machine was milling out the second sheet, I was sanding, routing, and rasping the pieces of the shelf. Following the completion of the second sheets, I also finished the additional pieces. In total, the milling and finishing process took about 5.5 hours.

Milling #

Resources #

https://www.makercase.com/basicBox

This week we will be using OSB, and center cutting end mills

• up cutting and down cutting end mills

Machinery Handbook

Diameter of tool is a good index of how deep you can go with an end mill Conventional vs climb machining

Class Notes: #

Shopbot: 4’x 8’ x 1’ work volume

Recitation Notes: #

I didnt feel like the recitation this week was very useful for folks in the arch section since Chris was the one operating the CNC machine and making changes to Mastercam.