Assignment 7

FabAcademy 2020

7

COMPUTER CONTROLLED MACHINING

Introduction

The numerical control CNC Router is a very useful tool when cutting materials such as wood and a wide variety of soft materials, such as acrylic, MDF or some metals such as aluminum, brass, bronze, among others.

Its beginning was in the industrial revolution in 1770, at the beginning the machines were operated by hand, although in the end there was a tendency towards automation. In 1952, John C. Parsons and the Massachusetts Institute of Technology developed the first numerically controlled milling machine, constructed of bulbs, using a binary code and drill tape. In 1976 the microprocessor was applied to computers, which finally gave a huge leap in the development and application of the CNC as we know it today.

A CNC Router is a machine controlled by a computer and its function is to make cuts automatically. The trajectories of the cuts are controlled by a system called numerical control, which sends the coordinates of the cut with millimeter precision from the computer. They are very useful in performing identical, high-volume jobs, as they often produce consistent, high-quality work.

Group Assignment

Test runout, alignment, speeds, feeds, and toolpaths for your machine

http://fabacademy.org/2020/labs/ciudadmexico/group-assignments.html

G A

GROUP ASSIGNMENT

Individual Assignment

For this assignment I have decided to develop a first prototype of a chair which will serve me both to apply the basic concepts of ergonomics for a 7 year old, as well as the use of digital manufacturing and the use of tools (Router CNC). The aim is that this first chair serves as a starting point to develop my final project.

The intention with this first design is that the chair is a robust element that avoids as much as possible the accidental movement of the chair by different users. For this reason, the chair has been planted as a large wooden block on the scale of a child between 6 and 8 years old.

For the design of this chair I have decided to use AutoCad, as it is a very familiar tool for me. Later I will use Rhino and Grasshopper for the following designs.

The design of the chair took into account the optimization of the material, since my intention was to use only a 1.22x2.44 meter sheet of wood.

At first I had some problems for not fixing the table to the CNC cutter. In the end, those little details are very important.

CNC design cutting

Pre-assembly. Due to the drill bit I used and the characteristics of the wood, some pieces were broken a little at the corners, however, I was no longer able to return to the workshop due to the health contingency due to COVID19. However, the end result was good.