What is cnc machine

(according with wikipedia)The CNC machine comprises of the mini computer or the microcomputer that acts as the controller unit of the machine. While in the NC machine the program is fed into the punch cards, in CNC machines the program of instructions is fed directly into the computer via a small board similar to the traditional keyboard.
The CNC machine comprises of the computer in which the program is fed for cutting of the metal of the job as per the requirements. All the cutting processes that are to be carried out and all the final dimensions are fed into the computer via the program.


Source:COEP college

The Shop bot machine at COEP is a 2.5 axis machine which is able to tool wood and and plywood, it has guide ways for X and Y axis, at the z axis is a router which is capable to spin at 18000 RPM It has a vaccum pump to such all the debris created by the tooling of the wood. It runs on 230V Ac supply, and can has a standard 8'*4' bed size.

Tooling

We are using end-mill as a milling tool for this machine, endmill is designed to traverse a path while cutting the material, this is the basic difference between an endmill and a drill bit.
sacrificial layer and squaring
Any shop bot machine has flat layer of plywood under the main cutting material, This is where we clamp our main part to. This layer is important or the protection of the endmill, in case the endmills plunges more than the thickness of the material it will cut into the sacrificial layer rather than the metal bed of the machine.


Source:coep college

Up to here we see the introduction of shopbot but now i move its design and actual working.