Computer-controlled Machining

Make something big on the Shopbot CNC router. Here is the link to see the details.

This week exercise was about Milling with showboat CNC Router and i have decided to design a chair which is inspired by Icosahedron Geometry and idea was to make such a design that you can use in different ways for different comforts. The material we are using for the chair is OSB(Oriented strand board). I have used RHINO as a tool to design chair and and i am using press fit joinery as detail to join all the pieces of the chair together. Here is the link to download the .DXF file for Chair.

Material and Fabrication Details

Material and Shopbot Details:
Material: OSB - (2500 mm, 1250m, 14.3 mm)(Oriented strand board)
Machine: Shopbot Gantry
End Milling Tool: 6 mm
Software: Shopbot Pathworks

Toolpath strategies:
Pocketing in oder to mark the holes so that you can screw the board in oder to fix the board on machine
Profiling with inside to make holes on the board, to fix the different pieces together(Press fit joinery)
Profiling with outside to cut the pieces out from the board so that tool bit run outside the line
Save work as ShopBot Part File (.sbp) to run on ShopBot or as .crv file to work with again in PathWorks.
Configurations:
Profile: Allow follow this line "means"
Cutting Depths: 16.3 mm (I kept 2mm more then material thickness to makesure that it will cut properly)
Material Vectors: on
Directions: Climb
Name: IkosaChair(name as you want)
Tool: end mill (6mm)
Cutting Params: Path Depth - 5 mm (step level)
Step Over: 8000 - 12000
Feed Rate: 40 mm
Plug Rate: 10 mm (z-axis)
Toolpaths: Toolpaths list
Select Order: drill, inside, outside
Select item: (drill) and then save as template
Select item: (inside & outside) and then save as template (you can save them separately if you are changing the tool)
Save complete projec for possible changes
Partworks 3d
Cuts > C3 Home X > Use sensor machine to find the 0,0
Load the File: first drill, second interiors and, exteriors
Set spinnable "ON" - green button on the desk control
Press "OK" after set the spinnable "ON"

IkosaCHAIR

Some important notes on the strategies and tolerance.

When you are using this joinery you have to be very careful how you are making the holes in oder to fix it together and that completely depends on the material thickness so the OSB board, so the board i was using was 14.3 mm and we made some test to find the tolerance and i need to make holes bigger, which was 14.6 mm so the tolerance was 0.3 mm for the shopbot machine. in my case, this tolerance worked out very well and i didn't had spend more time one cleaning the wood or fixing the pieces together so it always advisable to make a small test first to find the right tolerance for all these machines.