The assignment of this week concern to create "something big" with the milling machine.Before know it was something big, I've thinked about a Bat Box.
because I think they are really useful and ecological methods against mosquitos.
However it was a little small for the theme. Than I changed my mind into another useful thing (for me!). And I opted for a table for my sofa.
I made the project with Rhinoceros, and I made it with an height of 60 centimeters.
I've watched several junctions online on Make, and I've choose the Teddy bears (or this is how I call its!).

Machine used: CNC Milling Machine Enterprise.
Program used: Art Cam.

I made the model using Rhinoceros. I drawed the lines in 2D, and just extruted it to test the proportions.

Those "bear" junctions gave me a little problem. The the hole junction results with a size lower then the mill.
I avoided this problem just making a second file. One with holes and the second one with perimeters.
When files are ready, I exported in CAD.


Rhino files.
DXF files.

Before start the operation we require the protective device: gloves, glasses, mask, and ear protection.

For machine setting I used ART-cam, and the steps are those:

1-Set the surface width and depth (2'000 and 1'000 mm.)

2-Set the mill. On the line, inside the line, and outside the line (inside for holes, and outside for boards).

3-Finish depth. 19mm to be sure of the perforation, because the height of the surface was 18mm.

Setting:

Material: OSB (Oriented Stand Board) 2100 x 1100 x 19 mm.

End mill: 6mm.

Feed rate: 76 mm/s

Plunge: 50 mm/s

Spindle: 15000 rpm.

4-Set the mill options. Square top, 8mm circumference, and stepdown=5 (the machine mills 5mm every step, that means it need 4 passages to reach 19mm).



Changing the mill. ALWAYS with protections.

Now the machine was almost ready. And I need to set the origin point.

Was useful to make a photo of axis coordinates, to restart exactly the operations in case of problems.

I blocked the surface in anothe sacrifical one with screws and finally I started the mill.

I wasn't sure about the cutting process, and I wasted more space than necessary between the pieces.

Than I set the machine with board files, and clean the sawdust with the vacuum cleaner.
I got a problem in the process: I placed the surface too close, reaching the machine end point.
I resolved in the "old manners" measuring the distance and moving the base more distant from the machine.


Little adjustments with sandpaper and this is the final result!

This table was designe for a sofa use. It can be inserted near the sofa, letting the passage from the legs on the external part.