Assignment 3:Computer Controlled Cutting

Computer Controlled Cutting

This week assignment is based on Computer Controlled Cutting. The machines involved for cutting process are

1. Vinyl Cutting Machines

2. Laser Cutting Machines

In this week the other task is to make a Press Fit Design using parametric approach.

Vinyl Cutter

A vinyl cutter (or vinyl plotter) is a computer-controlled plotting device with a blade instead of a pen. A vector based design is created in a software program (usually Adobe Illustrator or Corel Draw). The vinyl cutter uses a small knife to precisely cut the outline of a picture into a sheet or piece of vinyl. The knife moves side to side and turns, while the vinyl is moved beneath the knife. The result from the cut process is an image cut into the material.

Vinyl Cutter used: GRAPHTEC CE6000-60

Before using, it is necessary to go through the specified manual to understand the basic functions of the machine.

Step 1:

Download the necessary drivers in your PC to interface the machine.

Step 2:

Attach a tool (cutter plunger, plotter pen) to the plotter.

Step 3:

Loading Roll Media

Lower the media set lever to raise the push rollers. Set the roll media on top of the stock shaft and then insert the roll media into the shaft. Position the media and push rollers to correspond with the width of media.

Step 4:

Aligning the push rollers.

Position the left and right push rollers to correspond with the width of the media.

Step 5:

GraphTech Studio is a software platform that comes with the plotter. To learn diffrent attributes of this platform i downloded this image from web. Next step is to import image in GraphTech Studio

Step 6:

After importing the image set the size of the image and then click on open the trace window as shown below.

Step 7:

Next step is to click on Select Trace Area and then select the image we want to trace

Step 8:

Now there are different trace settings to make trace as shown in green circle above. In this picture the yellow color represents the path along which cut tool will move. So it recommended to adjust the settings in such a way that coorect image is traced. After trace settings go to options available in red circle. Again we have three options which can be set according to user requirement. In my case i have selected the first option Trace, then separate the traced image and imported image. Delete the imported image from the window. Now click on open the cutters window .

Step 9:

To send the job to the cutter click on send to cutter. Before doing this make sure you have set the origin on the vinyl sheet.

Tools used for removing the cut material

Before cutting the picture for my project I have tested the sample images. Graphtec Studio is the platform to send images to the machine which is used in my lab.

For my project i have designed a AKGEC fab lab logo using CorelDraw. then imported it to Graphtech Studio.

To see the steps how i created the logo in CorelDraw refer my Assignment 2

Some snapshot while creating Logo for my Project.

Below you can find the logo for my project created using Vinyl cutting machine.

Laser Cutting

Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications, but is also starting to be used by schools, small businesses, and hobbyists. Laser cutting works by directing the output of a high-power laser most commonly through optics. The CO2 laser is suited for cutting, boring, and engraving.

Machine Used- SIL 682

Technical Specification

First step as guided by local instructor before cutting any shape on cardboard is to achieve the operating point. I have tested the sample shape at different Power and Speed. The test samples is shown below

Now to find the correct power and speed , fix one parameter (eg power) and vary another one (eg speed). If the material starts burning than vary the speed. If it doesnt work and you can opt to vary the fixed one.

From the test it s noticed that for P=30% and S=15 mm/sec the material started burning. The achieved operating point is P=30% and S=20 mm/sec.

Design of Press Fit Comb

For designing of Press Fit Comb I have used SolidWorks for 2D drawing. Below you can find the snapshot of sketch used to draw press fit Comb.The purpose of making this design is to know what cut thickness will give me the best press fit.

Details of the drawing

The design of the comb is parametric in the sense that slots thickness will vary according to the first slot thickness. We can change its hieght and length according to the user.

After designing the 2D model it is downloaded into the laser cutting machine. The comb after cut is shown below.

The observation made from press fit comb is the best press fit slot thickness for my material is 7.6 mm. The material is having thickness 7.7 mm

Parametric Design

In the parametric design assignment I have decided to make box of different sizes simply by using three basic blocks and connector.The steps taken to build this box are shown below. My design is parametric in the sense that using these blocks box of different sizes can be developed.

Next step is to design the 2D sketch of basic building blocks in SolidWorks

Basic Block 1

I have used parametric approach to design these 2D models. Parametric approach is very helpful when you are making blocks that have related dimensions.

After exporting these images to the laser cutting machine, the process of cutting started at achieved operating point (Power 30% Speed 20 mm/sec)

The basic building blocks for the structure are shown below

After taking out all the basic building blocks the remaining material is shown below

Snapshot for the base created from basic blocks

Connecters are used to provide mechanical strength to the base and side of the box.

After building the base connect the side of the box as shown in figure below

The final snapshot of the box after assembling the basic units and connectors are shown below.

Problems faced during the design

It is necessary to know about offset before making any press fit module. Offset is necessary to create in order to make a perfect attachment of modules. Initially design created by me was without taking any offset and the problems which occurred was during the attachment of modules. While removing the cut material from cardboard it is not coming perfectly. In order to resolve this perfect cut for a material is required. To achieve operating point a test should be conducted before cutting the actual shape.