Week 3: Computer Controlled Cutting

Assignment of the week:

Group assignment:

• Characterize your lasercutter's focus, power, speed, rate, kerf, joint clearance and types.
• Document your work to the group work page and reflect on your individual page what you learned.

Individual assignments

• Design, lasercut, and document a parametric construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways.
• Cut something on the vinyl cutter.

Learning outcomes:

• Demonstrate and describe parametric 2D modelling processes.
• Identify and explain processes involved in using the laser cutter.
• Develop, evaluate and construct a parametric construction kit.
• Identify and explain processes involved in using the vinyl cutter.

Requirements for the documentation:

• Link to the group assignment page.
• Explain how you created your parametric design.
• Document how you made your press-fit construction kit.
• Document how you made something with the vinyl cutter.
• Include your original design files.
• Include hero shots of your results.

Here comes another schedule for another week

Group Assignment

Summary

Laser Cutter:

A laser cutter is a tool used in prototyping and manufacturing to cut and etch flat materials. It operates by directing a focused laser beam to pierce and cut through materials according to specified patterns and geometries.

Techical Specifications:

• Work Area: 24″ x 12″ (610 x 305mm)
• Material Thickness: 7″ (178 mm)
• Camera System: 1 overhead
• Wire Connectivity: Included
• Resolution: Fully-flexible & user-controlled from 75 – 1200 dpi
• Maximum Engraving Speed: 120 IPS (3.05 m/s) with 5G acceleration. Computer-controlled in .001 increments up to 100%
• Color Mapping Feature: Links Speed, Power, Frequency, and Raster/Vector mode for more precise engraving
• Internal Memory: Store multiple files up to 1 GB. Engrave any file size
• Operating Modes: Optimized Raster, Vector, and Combined mode
• Auto Focus: Included
• Ventilation: 350-400 CFM (595-680 m3/hr) external exhaust to outside or internal filtration unit required. One output port, 4″ (102 mm) diameter

This is the C02 laser cutter that we have in our lab

These are all the functionalities of the touch screen control panel

I got the above 2 images from an online Epilog Fusion Edge Laser Cutter handbook .

Safety measures to keep in mind!

Fire Hazard

Laser systems can produce high temperatures, especially in vector cutting, and can result in burning when used with materials like acrylic. Always remain with the laser while in operation, make sure the area is clear of combustible materials, and have a fire extinguisher nearby.

Safety Features

The Epilog Model 16000 & 17000 laser systems have safety features like safety enclosures, interlocks that de-energize the laser when doors are open, visible emission indicators for the Laser Diode Pointer, and more. Do not remove panels and NEVER defeat the door interlocks.

Laser Safety

These laser systems are Class 2 laser products and conform with safety standards. Do not gaze directly into the laser beam. NEVER operate the engraver without protective covers on at all times, or look directly into the Laser Diode Pointer.

Electrical Safety

The AC input power is potentially lethal. Do not remove access panels while the machine is powered, and do not make or break electrical connections while power is applied. Do...

• Operate the machine under proper ventilation and housekeeping using the Laboratory Hood
• Keep the machine clean
• Always remain with the machine when in use

Do Not...

• Operate the engraver while unattended
• Operate it without proper ducting or ventilation
• Engrave or vector cut PVC-based products
• Modify safety enclosures

Characterizing Laser Cutter's Speed and Power!!

Key learning:

To get the best results with laser cutting, you need to balance how powerful the laser is and how fast it moves. For thicker or tougher materials, you might need more power. But if you go too slow, the material might burn. So, adjusting the speed helps control how much heat the material gets. It's like finding the right recipe for each material and design by trying different settings until you get the perfect cut.

KERF

Kerf is defined as the width of a cut or width of a material that is removed by a cutting process.

Laser Cutter Kerf Measurement:

For this week, one of our assignments was to characerize the laser cutter's kerf. Now, measuring kerf size accurately is essential to ensuring your laser machine's performance for your desired outcome.

material_thickness - kerf = slot_width

How to Measure Kerf?

These are the steps that we followed to measure the laser kerf:

• Design a piece with known dimensions. Keep it fairly small.

• Cut it with the laser cutter.

In our case we designed a simple shape with slots which differed in size by 0.2 mm

• Measure the slot width.

We used a digital caliper to measure the slots accurately

• Compare this to the measurement that you had in your file and calculate the difference between them.

• Divide the result from this calculation by two. (Since you have two lines that were cut, left and right or top and bottom).

• We got our average kerf as 0.1 mm!!

Here is the complete Group Assignment

Individual Assignment

Parametric Construction Kit

HEROSHOT!!

The third key concept is parametric design. This is an ordered way of working where specific details are given only in relation to one or a few base or control measurements. Then you are able to change the dimensions of the geometry by altering only those control measurements and the other, dependent, dimensions adjust themselves.

For the parametric construction kit, I decided to make a pressfit design in fusion and here are all the steps:

Pressfit design with Fusion 360

For the pressfit parametric design, I explored some ideas on google and found some really nice and beautiful designs. But I found them quite complex plus there weren't any TUTORIALS for the design!! So, I decided to make this as I found it simple and cool.

For this, I created my own design in Fusion 360

Design 1:

1. First set parameters for your design and to calculate the slot width, subtract the kerf from the material thickness.

To navigate to the parameter box, first go to modify and then to change parameters



We got our kerf as 0.1 mm, so we multiplied by 2 as we are calculating for two sides and subtracted the value from the material thickness which gave us the

slot_width


2. Then create a circle on the base sketch and set the diameter as circle_diam - slot_length

3. Use the offset tool on the sketch and set the offset value as circle_diam

The space between the two circles gave me the

slot_length


4. Extrude the space between the two circles. Set the extrusion value as slot_width

5. After the extrusion, create a side sketch of a square using the rectangle sketch tool with slot_width as its side length.

6. Then cut through the ring by using the extrusion tool.

Now we got a slot with the correct slot lenght and the correct slot width.

7. SEVEN MORE TO GOO!! Actually NO! Use the circular pattern tool to make the seven remaining slots by referring to the first slot.

Here are the results:

8. Make the first sketch of the inner circle visible and extrude it by setting the value as the slot_width

Design 2:

1. First set parameters for the sketch and to calculate the slot width, subtract the kerf from the material thickness like we did for Design 1.

2. Create a sketch of a circle and extrude it by setting the value as slot_width

• I made the circle diameter twice the value of the previous design circle.

3. Then split the circle in two and create another sketch on the semi-circle for the slot.

• To make the slot on the semicircle, first draw a square by setting its side length value as circle_diam/4
• Then make a center rectangle on the center line of the square by setting the width and length as slot_width and slot_length respectively.
• Do the same for the opposite side.

4. Then go back to sketch mode and make a circle which just meets the corners of the squares.

• Extrude the circle which and we finally get the shape!!!

Here is the result!!!

Chamfering

After I was done designing the shapes, I chamfered the edges.

Saving svg file for laser cutting:

• Now, to make the design suitable for laser cutting, I used the project tool to select the top face of the shape.

• Then, I saved the file the sketch as a dxf file.

• To arrange the designs for laser cutting, I used inkscape.

• First I set the width and height of the document as 60 cm and 30 cm respectively as this is the maximum area that our laser cutter can cover.

• Lastly, I arranged the designs efficiently on the page and saved it as an svg file.

ALL DONE!!!

Assembling Pressfit Designs

Here's the design I wanted to make!!!

And guess what?? CINDERELLA'S CARRIAGE!!

Vinyl Cutter:

This is the vinyl cutter that we have in our lab:

Model: GS-24

Input: 24 V , 0.9 A

Maximum cutting area width: 22.9 in (584 mm), Length: 984.25 in (25000 mm)

Maximum cutting speed 19.69 in/s (500 mm/s) (all directions)

A vinyl cutter serves as an introductory tool for crafting signs. It operates by directly cutting computer-generated vector designs, encompassing patterns and text, onto a roll of vinyl. This vinyl material is loaded into the cutter and fed via either a USB or serial cable connection. Primarily utilized in sign-making, vinyl cutters are instrumental in producing banners, advertisements, and various signage.

The following image shows a labelled vinyl cutter with the function of each component. This is the same model as we have in our lab.

Image Source.

Here are the functions of the operation panel:

Image Source.

I got the above images from google

For the vinyl cutting, I decided to print a sticker of me and my friends that Sir Rico drew for us!!!

So firstly I had to use 'trace bitmap' tool for the process which I have done in detail in the previous week but here is a very brief process:

1. Go to the "Path" menu and choose "Trace Bitmap."
2. In the Trace Bitmap dialog box, adjust the settings according to your preference, such as the number of scans and threshold.
3. You can then fine-tune the traced vector image using the editing tools in Inkscape.

That's it! You've successfully traced a bitmap in Inkscape!!

This is the eagle gang, by the way. We got this name after our instructor, Sir Anith's former friend group name.

Printing sticker on the vinyl cutter:

Import Design: Import your design into the cutting software. Ensure that the design is correctly scaled and positioned within the cutting area.

Configure Cutting Settings: Set the cutting parameters such as blade depth, speed, and pressure based on the type and thickness of the vinyl material you're using.

For this cut, I used the pre-filled value using the material selector : - Force : 10 - Speed : 5

Perform Test Cut: Before cutting your entire design, it's a good idea to perform a test cut on a small piece of vinyl to ensure that the settings are correct.

Send Design to Cutter: Once you're satisfied with the test cut, send the design to the vinyl cutter for cutting. Make sure the cutter is set to "cut" mode.

The above parameters (force and speed) worked for my test cut so I am proceeding with my main design!!

Monitor Cutting Process: Keep an eye on the cutting process to ensure that the vinyl is being cut correctly and there are no issues.

Your sticker is now applied and ready for use!

This is the the final result of my cut! And it turned out pretty well!!

I had a really hard time weeding as the graphics were pretty intricate but I had fun!!

Design Files

• Pressfit SVG
• Fusion Pressfit Design
• Vinyl Cutting Svg

Here is the link for our group assignment Group Assignment:

I made the whole documentation in markdown and generated the html format from chatGPT. So, special thanks to chatGPT for helping me convert my whole Markdown text to HTML!!!

Thank you for visiting!!!