Assignmnt-3

Computer-control cutting

Task of the week	What I have did
Group assignment :	Studied laser cutter.
Characterize your laser-cutter's focus, power, speed, rate, kerf, and joint clearance.	Calculated the kerf for different materials in Group assignment.
Individual assignment :	Used different 3D and 2D designing softwares.
Design, lasercut, and document a parametric construction kit, accounting for the lasercutter kerf.	Designed and cut construction kit.
Show the different ways of assembling the construction kit.	Present the different ways of assembling it.
Design something for Vinylcutter.	Designed a logo for vinyl cutter and have cut it on vinyl cutter.
Cut the design on Vinylcutter.
Include the design files.

Week 3 :-

This week was dependent upon the previous week where we have explored our CAD designing tools by using various CAD software. This week we have one group assignment in which we have to study laser cutter in our lab. In which we have to find out Kerf, focus, power, speed, rate, and joint clearance for various non-metallic materials like MDF, cardboard, acrylic, plywood …etc. But we have found out 'Kerf' for MDF, cardboard, and acrylic.

Group assignment

In group assignment our task was to study all parameters related to laser cutter. Also we have to use consider that parameters. Also we have consider that parameters in our design to a construction kit by using number of laser cut parts. For more detail information related the group assignment work please click on above link (Group assignment).

Individual assignment :-

In individual assignment we have to cut any design on vinylcutter also we have design a construction kit with the help of parametric design part.

All about "Laser cutter" :-

Laser cutting is a technology that uses a laser to slice materials. Laser cutting machines are used not only for industrial manufacturing applications but it also can be used by schools, small businesses, and hobbyists. Laser cutting works by directing the high-power laser through optics. In our lab, we are using a CO2 laser. These types of laser cutting machines are used for cutting non-metal.

Specifications of “SIL laser cutting machine” : -

Cutting Material : - Acrylic, MDF, cardboard...etc
Automation Grade : - Automatic
Laser Power : - 100 Watt
Laser Type : - CO2
Cooling Method : - Water Cooling
Drive Type : - Stepper Motor
Engraving Speed : - 0-64 m / min
Working Voltage : - AC 230 V + 10%
Positioning Accuracy : - 0.1 mm ( MAX )
Cutting Speed : - 0~30 m / min
Working Area : - 1300 x 900 mm
Temperature Deg Celsius : - Temp 0 c ~ 45 c
Control Software : - RD-Works

Terminologies related to Laser cutter : -

Kerf : -

The laser itself has a thickness, called a “kerf”. The laser burns or vaporizes the material comes in contact with it, the kerf is the thickness of the portion of the material that is lost when the laser cuts through the material. For calculating kerf we have used this formula, (kerf=(X-Dir kerf+Y-Dir kerf)/2)

Focus : -

Understanding the rules of laser beam focusing is crucial to deliver a high-quality laser-cut parts. Maintaining focus position within the material is crucial to the repeatability of laser-cut parameters and for producing consistent edge quality. Focusing of the laser beam in ‘Laser cutter’ is don with the help of focusing lance. We place this lance in such a manner so that the laser will strike on it and results into the focused laser beam.

Speed : -

The selection of cutting speed is based on material and the thickness of the sheet. Different cutting speed will cause a great impact on the laser cutting quality. Selecting the appropriate cutting speed, can not only improve the work efficiency of laser cutting, but also get a better cutting quality.

Power : -

The most important factor that we need to consider while selecting the laser power of our laser cutter is the application that we want to use most often with laser. If we are using a laser cutter for engraving, the power between 25 to 60 watt with considerable high speed is good. For laser cutting of material we require power above 60 watts with the low cutting speed.

Safety factors : -

Operate the laser unless all covers are in place and interlocks are working properly.
Do not look directly into the laser beam. Laser beam is the invisible high energy which can causes severe eye damage.
Use materials that are inflammable, non explosive or will not produce any toxic by-products.
Remove material from the cutting bed after it has cooled.
Do not leave a laser cutting operation unattended.
Always clean up clutter, debris and flammable material in the laser cutter after use.
Always keep a properly maintained fire extinguisher nearby.
Do not use a laser cutter with a malfunctioning exhaust system or clogged air filter.

Parametric design in freecad by using spreadsheet : -

What is parametric design ?

The term “parametric” does come from parametric equations in math. In parametric design we have to set up calaculations where, we have to give some numbers and add the mathematical function to get desired output in the design.

For the parametric designing follow the steps : -

First open freecad and draw 2D sketch in sketure without any diamension.

Select 'spreadsheet' from the dropdown menu.Spreadsheet is get open in and we can see it in the model-tree of the sketch.

Double click in the column of spreadsheet and write any name for the diamension of the sketch also select in the next column and type the diomension.
Select second column and click on right button of the mouse. Window of cell properties is open, select on 'alias' and type the name of the diamension and press Ok.

Double click on any link from the sketch, go to skectcher again and select diamension, a window is get open. Now click on the dropdown arrow at the extreme right again a window get open.
Now write the name of the diamension suppose 'Length' and click ok.We can see the change in diamension of the skectch.

Apply the same process for each link of the sketch. Finally we get the parametric design.Where if we change one diamension of a link then the same diamension given to other link is also get change.

Click on "none" button to remove selection.

Click on colors option in the task menu and select curve to adjust the colour combinations of selected portion.

RD-works : -

In RD-works we can arrange the blocks we are going to cut on the laser cutter. It will help us to arrange the cutting parts in the software. By using this software we can save the wastages of material we are going to cut on the laser cutter. In short RD- works is the virtual platform where can set the cutting parameters and also placing of cutting parts on the virtual sheet to save the wastage while actual cutting.

Steps for starting 'Laser cutter' : -

Press following buttons one by one to start 'Laser cutter' : -

Main switch ⇒ Isolation transformer ⇒ UPS ⇒ Air compressor ⇒ Cooler ⇒ Main button on laser ⇒ Lamp ⇒ Exhaust

First load a cardboard sheet on the bade of laser cutter. and adjust the focus by us leveller.

We don't have Probe which will be used to adjust the focus in the laser cutter automatically. Because it is not in the working condition. We have adjust the focus by using bed-leveller which is nothing but the cutted workpiece of acrylic material as shown in the image.
I have refer this document to understand the process we are following in our lab. The practical apporach to keeping your laser in focus.

Now adjust the position of header by using keys as shown below.

Load the images with multiple number in the memory of laser cutter.

Now, we have to start our laser cutter.

Laser cutter will cut the shapes as shown above.

Now, I have connect the shapes and have tried to build a stand to place rubber, sharpner and lot many things.

Also, I have tried to build a Pen stand.

Multi- purpose 'Pen-stand' is ready.

A construction kit :-

Week1-1

Vinyl cutter :-

Vinyl cutter is use to cut stickers with various shapes of logo, frame,...etc. Mostly this machine is use in "Radium shop".

Stepwise process for designing a logo in 'Coreldraw' : -

Open coreldraw, draw the shape by using pen tool from 'Freehand' option on the left hand side of the screen.

Draw the sketch as shown below.

Fill the colour in the sketch by using 'Fill tool'.

Press 'ctrl+G' to group all changes in the image.And export image as '.png' from the file menu. Our image is ready.

Open computer with 'Ubantu operating system' Copy image in the pen-drive and connect it with the computer of 'Vinyl cutter' and feed that in the computer.

Operate vinyl cutter : -

After designing a logo now it's time for Vinyl cutting operation. Before using vinyl cutter for cutting logo we have set some parameteres for cutting our design as given below.

Now open Terminal and give command 'Fab' to opening 'Fab-module' software.

Load the ' Vinyl papar '. Before loading vinyl paper make sure that the hand lever should be at the down position. It is mechanical arrangement in the machine. After loading the vinyl paper press the lever in the upward position.

Difficulty that I have faced :-

At the first time when I have loaded the vinyl paper and started to move the header, It was not moving. Because I have the place the vinyl paper away from the paper detecting lese. So, while loading the vinyl paper make sure our vinyl paper should be on the paper detector lens as shown below. Otherwise the header does not move from it's position.

Now adjust the rubber roller at the exact position of the white strips.

In the below image we can see the header and the cutting blade for cutting vinyl papar.

Once we have load the vinyl papar and have fixed the position rollers. Now its time for fixing the position of (origin)header near the white strip as shown in the image. If the position is finalized then press enter. We can see all changes like position of origin, distance between rollers on the dispaly.

Enter the command Sudo fab for opening the software to operate vinyl cutter.

Open the image and apply all commands given below in the image.