Week 7 ( March 15, 2017)
Computer-controlled machining(CNC)
Assignment
Make something big (on a CNC machine).
CNC router (Or Computer Numerical Control router) is a computer-controlled cutting machine related to the hand held router used for cutting various hard materials, such as wood, composites, aluminium, steel, plastics, and foams. CNC stands for computer numerical control. CNC routers can perform the tasks of many carpentry shop machines such as the panel saw, the spindle moulder, and the boring machine. They can also cut mortises and tenons. ( Wikipedia.org ).
The CNC machine in our lab is J-cut 1325B type and the bed size is 130 CM x 250 CM. Depending on the type of material and purpose we have to be very specific on selecting the ‘bits’,
There are several types of bits based on the swirls,no. of flutes and arrangement of the bit-pattern:
1-Up-cut
2-Stright
3-Down-cut
4-Compression
This week's assignment is make something big using CNC machine. CNC is a big milling machine. We already used small milling machine for make PCB board at Week 4 but this time the machine is way bigger and more powerful.
My project for this week is a kids Chair, I designed by using onshape.com
I got to admit that this was not an easy task. First of all, I had to think about what I want to make. Since my classmates here were planning to make the furniture.
My link for the design is as follows My Onshape design
I designed he sides and as well as the chair structure in onshape after very much effort and exported to DXF format.
I scaled my design in to a miniature size and then I lasercut the design of miniature form to ensure that it fixes well.
CNC Machining
Firstly I loaded my dxf format file in to art CAM.Then I selected the parts to cut inside.
I choosed the milling tool as 3 mm
Then I defined the outside cut areas and generated corresponding tool path.
I loaded my art cam converted file .plt file in to the CNC controller and started to cut the design.
Finally I got my CNC cut output as shown in the picture above.
The problem with the final out put was I needed to file much to get it properly inserted inside the other