Assignment 4 :Computer Controlled cutting

Task

1. Group Assignment:characterize your lasercutter's focus, power, speed, rate, kerf, and joint clearance
2. Individual Assignment:cut something on the vinylcutter design, lasercut, and document a parametric press-fit construction kit, accounting for the lasercutter kerf,

The fourth week of fab academy is about computer controlled cutting,name itself describes the task.so,after wendesday's lecture, on Thursday our instructor gave us basic idea of our Laser and vinyl cutter and most important about "safety Insrtuction"she (Miss Komal Raut)divide us in group of 2 then we starrted actual on work.

Plan for this week

• 1. Characterise laser cutter & vinyl cutter
• 2. In group assignment -calculate kerf ,test laser cutter
• 3. In indivisual assignment -cut something on vinyl,cut parametric and pressfit design on laser cutter

Laser Cutting

At Vigyan Ashram we have "SIL"laser cutter

SIL built laser engraver and cutter which is engineered & manufactured in India.We are also having Epilog laser cutter but the bed size of it is smaller than SIL. we are using SIL mostly,If I will get time I will try Epilog also.

The "LASER” is Light Amplification by Stimulated Emission of Radiation.The laser is a column type structured beam having high intensity of light, with single wavelength,. In our case of a typical CO2 laser, that wavelength is in the Infra-Red part of the light spectrum, so it is invisible to the human eye. The beam is only about 3/4 of an inch in diameter as it travels from the laser resonator, which creates the beam, through the machine’s beam path,

Specification

Model No:1325 – 1318

Laser Type:Co2 DC Glass laser Tube

Laser Power:80 Watt

Processing Area(Bed size):900 x 600 mm

Working Speed :Adjustable

Power Supply ACv230V, 50HZ

Format Supported: .DXF .OBJ

Steps to start laser cutter

Mains(Power Supply)→Isolation transformer→UPS→Air compresser→cooler→mains(laser)→Laser on→Exhaust on→Lamp→redbeam on→Interface with computer→download the file→start →

The laser cutter can be operates using just mains and compressor but we are using all the equipment because

Kerf Calculation

Kerf calculation is the narrow channel left behind by the laser/saw.

for this calculation me and Manoj Sahukar,we tried two tests

What is this ?

This is a test of finding minimum kerf at different power and speed of laser for "MDF"material.In this test we design a structure in matrix form in horizontal direction we kept power constant and vary speed'in vertical direction we kept speed constant and vary power

How we did this?

We design the the rectangle as per above matrix design in "RD Works"(this is software we used for interfacing the laser cutter and .dxf files)and we set power and speed as per design

As file is ready now,set the bed level of laser by adjusting knob on laser cutter.as shown

After confirming the bed level,set the origin at required place,(chose the position of origin where material wastage can be minimize) then enter the file for laser cut trace the frame and start the laser,it will cut the file,our laser cutting video for kerf calculation is as below

What I did?

After laser cutting we calculate the kerf for cutted part by using vernier,in below image you can see the reading "39.79"for power 65%,speed 20 mm/s"and other reading are as shown in above table.

we found this different kerf readings

second test

For this test we used "comb",we design skech like comb having scale 2.2-1.5,cut it in 2 no.s for 2 mm thickness and tried to fit it in each other,Here we find 1.7 as a perfect match so kerf = 2.0-1.7 =0.3 mm

In this task I used solidworks and fusion 360 for parametric and pressfit design,I simply draw the different shapes that can be fit in different combination,and cut it on laser by adding kerf value

After cutting on laser cutter ,models look like

Credits: I refered documents of last year Fab academic student"Brandon Prentice"

Laser Engraving

I made penstand of cardboard,then I tried laser engraving on cardboard itself I used design I draw in previous assignment,In inkscape I tried diffrent designs of circle so in this week I am engraving the same for engraving I put speed 100 and power 15 for cardboard.then result is like

Here we can understand laser cutter,kerf calculation,parametric and pressfit design.

Download Laser cutting files here

Vinyl Cutter

On Thursday our instructor gave us idea about vinyl cutter.We have "Raland Camm-1"vinyl cutter

Material required-Vinyl paper,X-acto,maskking tape,vinyl cutter,etc.

Steps to follow,

1.Design the file in vector software- I used corel draw,I made title of my project"Key Security system",& for my plywood board"Key Holder"& one "key" symbol

For design I simply used the text format choose the different font for each letter ,then I draw simple 'Key' using free hand tool and line and saved it as .png

After designing part set your PC for interfacing as below

Vinyl Cutter setting

Software setting

Open terminal on Ubuntu OS,fab module screen will open,then enter password,then select image format from dropdown ,load image,select vinyl cutter,segments from dropdown

Machine setting

After making this switch on the vinyl cutter,set the paper roll ,check origin,

After cutting on vinyl ,for proper removal of the paper we need maskking tape and x-acto

Download Vinyl files from here

Screen printing

After vinyl cutting the file I have to explore more,so our instructor told us that we can use the left cutting part we can use for screen printing,good idea,but we were unable to do it because we were unknown about"screen Printing" then Mr.Vishal Jagtap from Vigyan Ashram helped us ,he took one explainatory section about

What is screen printing?
This is a method in which ink or colour is applied directly to the surface to be printed or vinyl cutted. The image to be printed should be transferred to the screen such that the non-printing areas are blocked off and the fabric serves as a stencil. The ink is wiped across the screen to pass through the unblocked pores and reach the substrate.

There are number of techniques and machine for scrren printing but we did it using traditional method,

Steps to screen print

Error and Solution

When I started working on vinyl,I got two errors on display of sensor error and origin error.I repeate the whole process to solve this process then I found that sensor error occurs due to mis allignment of paper roll on sensor,and origin error occurs due to I moved the slider manually away from the origin ,then I fixed it.

Summary