week08

Computer-Controlled Machining

This week assignment was to make something big using plywood. I have used the Oriented Strand Board (OSB), an engineered wood particle board formed by adding adhesives and then compressing layers of woodstrands in specific orientations and I used the CNC machine to mill and cut the board. The dimensions of the OSB are 2500 L x 1250 W x 15 Thick.

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Inspiration

As an interior architect and having a background in design, I am very passionate about furniture and product design. For this week assignment, the first thing I thought about was the memphis group design movement which started in the early 80's and which was founded in Milan by Ettore Sottsass. Their design was the combination of value, chromatic palette, materials, and versality. Their main aim was to reinvigorate the Radical Design movement. The group intended to develop a new creative approach to design.

So I have decided to make furniture (A chair and a side table) and get inspired by the memphis design and try to play with the geometry shapes and maybe even add some colors.

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Design Process

I draw the design in SolidWorks a new engineering software for 2d and 3d design that I really found friendly to use. There are 3 steps to follow to build 2d and 3d design

Parts: to build each part of the design in 3d with the joints separalty in different files

Assembly: to add all the parts of different files in the assembly document to create the final shape and connect the joints together

Drawing : to add the same parts in the drawing document but in 2d to create a sheet with the board dimensions and all the parts inside the area to finally send it to the machine. The file should be exported as DXF

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Mill tools

Here is a clear list of the milling tools with all the dimensions.

Climb milling is when the direction of cut and rotation of the cutter combine to try to "suck" the mill up over or away from the work. Here is a diagram showing climb versus conventional milling :

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CNC machine

I opened the design as DXF in RhinoCAM, a Rhino plugin, to generate the path of the milling. The file should be prepared by steps:

Drilling: First step is to generate the points on the board to drill using a drill tool (3mm diameter) so the board can be fixed into the machine.

Profiling: Second step is to generate the inside parts using the correct mill tool (which is different than the drilling, 6mm diameter)

Profiling:Third step is to generate the outside parts using the same tool as the inside (6mm diameter)

Here is a clear list of the milling tools with all the dimensions.

Once all the steps are generated into gcode, the CNC machine can be able to read it using the Mach3CNC software. Few notes before processing:

Screw the board into to the machine

Always set the home origin

The Tool's length should be bigger then the board's thickness

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Failure

Note to self:

Always check the direction of the lines in the drawing (Rhino) before sending it to the machine, and MAKE2D

Better use chamfer edges for the joints !!

Always check the dimension of the board and specially the thickness in different location.

References

Some references that were useful and handy:

Flexible stream

Sketch chairr

Layer chair

Deferred procrastination

Love letter to plywood by Tom Sachs

Download the files here : Furniture file - solidWorks