I start my week 03. journey, Computer controlled cutting by designing, getting to know what kerf is, its importance, joints, getting to know some machines and parametric data. So lets begin by knowing the
machines will be using for this weeks assignment.
Laser cutting machine
What is a laser cutting machine?
Laser cutting machines is a tool used in a wide range of industries for precision cutting and designing projects. The laser cutting machine emits a high powered laser beam to either cleanly cut or a specific design on materials such as steel, plastic or wood. It is generally used
more for industrial manufacturing applications and the beam will either burn, vaporise or melt away the excess product, leaving a superior finished design or edge. A laser cutting machine has settings known as the computer numerical control (CNC), as well as laser optics, which control
and direct the laser beam’s intensity for the desired design effect or the specific cuts required in a manufacturing or design project. The laser beam is generated by a process whereby electrical discharges or a lamp trigger a lasing material within a confined container causing a chemical
reaction, resulting in a high powered beam being released. The beam is then reflected using a mirror in a stream of monochromatic light. From the mirror, the light is then directed by fibre optics or mirrors to the work area, with the narrowest point of the beam cutting or making the design
sketch on the material.
Laser cutting machine is often used in engineering for the precision cutting of components of machines. For industrial applications, a laser cutting machine is often used to cut structural and piping materials and flat sheet material such as metal. The CNC setting can also be
changed to etch or engrave all types of designs on metal, wood and plastic. Speciality CAD (computer aided design) software is used to program the CNC and direct it to perform either the cutting, engraving or etching specifications required for the laser cutting project. The size and
capacity of the laser cutting determines whether it can be used for smaller or larger-scale manufacturing projects.
A vinyl cutter is a versatile tool that is used to create a wide range of products from custom gifts to signs and banners. It is a computer-controlled cutting machine that uses a small blade to precisely cut vinyl material into various shapes and designs. Whether you're a small
business owner, a creative hobbyist, or just looking for a new side hustle, a vinyl cutter can be a valuable addition to your arsenal of tools.
One of the key advantages of using a vinyl cutter is the level of precision and detail that it provides. The small blade size allows you to follow intricate patterns and designs, making it the perfect tool for creating intricate stickers, decals, and wall art. This precision also means
that you can create clean, accurate cuts every time, ensuring that your final product is exactly what you envisioned. Another advantage of using a vinyl cutter is its cost-effectiveness. You won't have to spend a lot of money on expensive equipment or materials, and the vinyl material itself is
relatively inexpensive. This makes it an ideal solution for small businesses and hobbyists who want to create custom products without breaking the bank. Additionally, vinyl cutters are incredibly versatile, so you can create a wide range of products to suit your needs. Whether you're a small
business owner, a creative hobbyist, or just looking for a new side hustle, a vinyl cutter is a valuable investment that will help you bring your ideas to life.
Before we start lets learn a little bit about parametric design. Whay is parametric design?
When we talk about parametric design is a process that helps people in their designs, wether they are complex or not. This process is not only use by engineers, it also been use by arquitect, designer for example.
This process uses algorithms and mathematical equations so we can create customized products considering the material we will use. So it doesn't stick to a specific area. Now, this will help us because we can
input parameters to produce a much better and detail result.
Why is this important?
Well in this week we are learning about Computer controlled cutting so how it can help us:
Getting to know how the cnc laser cutting machine works.
Understanding kerf, which I explain ina section below this one.
It gives you a better understanding of the results you get of your design.
It helps define parameters that can benefit the design your about to manufacture. For example speed, intensity of laser.
Once you get the parameters you can take decisions on your final result, you which to cut or engrave.
And of course considering the material your using to make your design. For example it's not the same to cut or engrave in plywood then acrylic.
I start by making a design of a table that can show me the results and relation between power and speed set int the LSM (Laser cutting machine):
I design a table that shows the results of adjusting power and /or speed.
I define a table 23cm x 30 cm and a circle with a 1.5 cm diameter.
Now, I use the circular pattern command to repeat the circle the times I need. At the left part of the screen, you’ll see some parameters we must define, for example:
Direction #1: The horizontal line of the table, x axis.
Instance: the times you want to copy the circle, 10 times.
Direction #2: The vertical line of the table, y axis.
Instance: the times you want to copy the circle, 10 times too.
Select the entity you want to copy, in this case the circle.
As you see in the last imagen it copies in the wrong direction, so we must change the direction.
And there we have it, but we must separate them.
Make some adjustments and extrude.
I forgot that I was going to put text, so I added more space, add the numbers for the power and speed level:
2. Setting the Laser cutter machine
Before using the machine we must do some important things. I share with you the details:
Google the software we're going to need for the Laser cutter machine.
The software name is: RdWorks.
The latest version is 8.01. Here's the download link: RdWorks
So I install it.
Preparing the files:
Now we are going to prepare the files so they can be use in the machine:
I went back to solidworks and open the parametric table and save in format .Dxf (Didn't know about this file extension).
.Dxf files are use for the laser machine.
I open Rdworks software and import the .Dxf file (parametric table)
After importing, we must modify some parameters:
Speed
Min power
Max power
Set colors to the circles, because i'm going to specify to the laser cutter machine what to cut.
I did this to cut line by line and make some modifications and understand the results.
I set the 3 parameters for each circle.
From left to right, I define the speed of 10 for the first line of circle. Then I will increase +10 for each line.
From left to right, I define the power to: 10 for min and 10 for max. I'm going to increase in +10 for each circle in the same row.
Set the priority of each circle.
By doing this I'll just have to change de speed +10 for each row.
FYI:Before cutting, triple check what you set to cut.
Double clic the output option at the right side of the Rdworks screen. By doing this you'll see the output changes to yes or no.
Configuring the machine:
We are almost done. Now we prepare the machine and make sure its ready to cut:
When the design is ready, I have to save the files in the right extension, .Dxf.
Set the table in the Laser cutting machine.
From de config option, RdWorks, set the laser head position to define where the cutting will start.
The green square and the cut origin must be in the same position.
Now we use the "white rectangle" and set the distance the laser will cut (3rd image, 2nd row).
Turn on the air extractor or you will fill up all over the place with smoke.
Connect the computer to the USB port of the Laser cutting machine.
Now we are ready to start cutting.
3. Kerf table design
Kerf is a new word and i wasn't sure that I understood it the first time they explain it to me. So, i thought it was like the waste of the material, but NO! I was wrong. I think I got until I cut the "Kerf table" and
take some measurements. To begin with this assignment I design a "kerf table" to understood and getting to know what was the kerf I have to consider.
Definition:
Kerf is defined as the width of a cut or width of a material that is removed by a cutting process. It was originally used to describe how many pieces of wood were removed by a saw, because the teeth on a saw are bent
to the side, so that they remove more material than the width of the saw blade itself, preventing the blade from getting stuck in the wood. When talking about CNC shape cutting with typical cutting processes, a kerf is the
width of material that the process removes as it cuts through the plate.
Inside the table I draw 20 vertical rectangles, width = 0.5cm and height = 8cm.
For this I consider plywood material of 1/4 inch.
I start cutting the Kerf table.
You can see there's a space at the end tof the "kerf table".
I measure the space, it's 0.87cm, this is the total but not my kerf.
Now I did some calculations:
According to my measurements:
I use the caliper tool and a ruler. (just to make sure, I took the rigth measure)
I have a 0.87 cm space at the end of the "kerf table".
So I took the 0.87cm and divided by 20 (amount of rectangles I cut).
the result of the division is 0.0435cm / 0.0171259843 in / 0.435 mm.
the result of the division is 0.0435 cm.
Remember i did this in a 3/16 in plywood.
4. Joints
I started my day designing joints using SolidWorks. Remember to consider kerf. I have to add some ecuations in solidworks and for every design and of course consider the measurement units of:
Kerf is 0.0435 cm
table, the width of my plywood, 3/16 in.
Press-fit joint
I draw the joint, set some relations and dimensions. (for this I’m using cm)
Next, I set the dimension and extrude.
Chamfer
For the next joint I realize that the press-fit joint and chamfer were similiar.
So I use my first joint design and make some changes, and save it with another name.
In this one I define a chamfer of 0.4 cm and that’s it for this one.
Snap-fit
For joint #3, I use joint #1 again and make some changes. But this time I tried the mirror command. With this I just need to do half of the design and replicate it.
Got to be careful with this command, you must set the dimensions correctly so that the mirror works as we want.
I use the press-fit joint again and make some changes.
I add it a 0.25 cm radius loop and a cut of 0.5 cm to the right side of the design.
I added a constructive line that will serve as a basis point to mirror the design.
Flexure
For this joint, I used snap-fit joint.
Add some details, like the rectangles beneath the rectangles with the half circle.
I apply the mirror command to the rectangles I added.
I used the cut extrude command.
Finger
For this joint im going to start from scratch .
I draw a 4cm x 4cm square.
I draw a 0.70 cm x 0.50 cm square inside the first square.
comando para repetir y extruir y cortar .
Results:
After designing in solidworks, I have to save the file in .Dxf extension files. I need this so the Laser cutting machine can read or see the desing.
Here are some results:
Individual Assignments
5. Box
For this week assignment I made a box, use some joints to put it together and consider kerf (not as easy as I thought). Had to do lots of test.
