MAKE SOMETHING BIG

The goal this week was to design and fabricate a 2D object into 3D. Regarding the design, I wanted to fabricate a Kneeling chair.So i designed the 3D model in Rhinoceros.

The Material we had available was one piece of O.S.B in order to make something big with this size 2500mm (length) x 1250mm (width) x 15mm (thickness)

For this assignment we could'nt use nails or glue and before designing anything was important to have a look to the wood joints.

This model seems perfect also to join two pieces of wood through two sections, so I drew the dog-bone fillet.Before cutting my big piece of O.S.B I made a test to check the holes of the join 0.5 mm smaller than the piece for a better grip.

The final 3D model

Partworks

Once the Rhino file was ready I used the command Make2d in Rhinoceros to take their blueprints.
I nested them in a square equal to the dimentions of my O.S.B. to mill and I exported as a .dxf file to Partworks,the CAM program I used for making my G-Code.The first thing to do was set the size of working area in the Job Setup, then Z Zero and the Thickness of the material.Then I opened the .dxf file, joined all the lines as vectors,tool joint open vector under edit vectors,select CNC mill radius,add clamps (machine-> table clamps) to fix wood to the machine,select toolpath,the drill Endmill 6mm,cutting parmeters,feeds and speed with a spindle of 1200 rpm, feed rate 40mm/s, Plugin Rate 20.
At the end Save toolpath and Calculate and the program has elaborated a strategy in 2D for the cut.

PROFILE INSIDE

PROFILE OUT

Shopbot

- Place the wood sheet in the machine and fix it
- Select and fix the tool mill. - "home" the machine.(I used the arrows yellow console and moved the spindle)
- Add 20mm to the z-axis ( to avoid to touch the board)
- Remove the tabs created with Partworks with a hammer and chisel
- Remove screws using a driller
- Remove Material

Issue during the cut: I left not enough space between 2 parts of the chair and one of my OSB parts has broked a little bit. I used a sand paper to adjust it.

Final result

Considering the Material we used to complete this assignment the structure is not rigid enough. To ensure the requested strength of a chair while using the given Osb matarial I added 3 additional sections within this specific prototype. Only removing the additional structures would ensure the requested strength, using proper materials like Plywood or Wood.

KeyShot render and the 3D model below.

DOWNLOAD FILES.