Computer-Controlled Cutting

As above title of this week suggests, it is all about Laser and Vinyl cutting. From this week our fab academy is going much and more interesting. This week is full of learning environment, learning and working with different CAD softwares like, SolidWorks, InkScape, and Rhinoceros 3D. And, working with machines like 'Epilog Laser cutting Machine' and 'Vinyl cutter machine'.

    Assigned tasks:

    There are two assignments of this week:

  1. Group Assignment
    • Characterizing lasercutter, making test part(s) that vary cutting settings and dimensions
  2. Individual Assignment
    • Cut something on the vinylcutter
    • Design, lasercut, and document a parametric press-fit construction kit
    • Accounting for the lasercutter kerf, which can be assembled in multiple ways

Group Assignment:

For group assignment, we are using a material test card which we found on Internet from Material Test Card for Laser Cutting and Engraving. This card is helpful to document the machine performance on any material. We are using 4mm cardboard to test machine parameters. In this test we are checking its engraving power, engraving performance on different font sizes, cutting accuracy by cutting different size shapes and, parabolic and straight line flexes by varying line spacing

Steps For Laser Cutting Machine

As per instructions we set cutting line strokes to 0.001 inches. Other vectors except 0.001 inches set to engrave with respect to their greyscale color. Then we convert our SVG file into PDF while setting page size to 32x20 inches from document properties and selecting 600 dpi as resolution for rasterization

setting up file in svg and convert into pdf

Now we open PDF file and press Ctrl+P to open printing properties, Select "Epilog Engraver WinX64 Fusion" in Printer Tab and "click Properties"

Raster/Vector power and speed settings

Click on combined in "Job Type". We set Raster power to 100% and speed to 100%. and Cutting power to 30% and speed to 10%, after setting up parameters click "OK" and the job transfer to Epilog Job Manager.

Job information in Epilog Job Manager

We select our job and check the preview by clicking on "preview".Select the location of job by dragging the image in preview menu and set where we need it on Laser machine bed, and click "Save"

Job Preview Window

After selecting the location click Save and click on print to transfer job to laser cutting machine.

Display of job information on Laser Cutting Machine panel

Press "GO" on machine panel and leave rest of the work on machine.

Laser Cutting Machine while working on Job

The perfect End Result.

Final Product

Comparision

Individual Assignment:

1. Vinyl cutter

A 'Vinyl cutter' is a computer controlled machine. This machine is controlled by a computer and operate similar to a printer. A vector based design is created in software program (I used InkScape) and then sent to the cutter where it cuts along the vector paths of the design. So, it doesn't work on bit map images, it works on vector based images or texts.

Steps of my designed project for Vinyl Cutter in InkScape

For this task, I created a design combination of my image and texts. In beginning, I put my image then applied 'Bezier curve' function and 'edit path by node (F2)' function for removing the background of my image. After this I used 'Trace bitmap (Shift+Alt+B)' function to gray out the image. Now, I put my image in the circle and wrote text then used 'put on path' function to change texts as circle, again i repeat this for another layer of words then cut down the two circles. And, also played few other functions to beautify my design.

Design process images are give below:

My photo, then I removed its background color


'Trace bitmap (Shift+Alt+B)' function to gray out the image


Drawing circles and writing words using text tool


Design is complete and ready for cut in "Vinyl Cutter machine"


Once designed was complete, I export the design in 'png' format then converted it into 'jpeg'. I opened this image in Roland Cutter software 'Cut Studio' and proceed the further steps.

Design is imported in Cut Studio


Steps of using Cut Studio

The necessary thing is to set the position of the vinyl sheet in vinyl cutter. So, I am writing below its steps.

Steps of inserting Vinyl Sheet in Vinyl Cutter

Vinyl cutter process images are given below:

Setting vinyl sheet and alligning it through little wheels. As described above in point no.3 and 4


Selecting sheet type, I used a piece of vinyl that's why I select PIECE. As described above in point no.6


vinyl cutter machine is in working condition, cutting my design through its small pin. As described above in last point, point no.8




Peeling out the unwanted sheet from design


Plugging the remaining material from on transfer sheet


That's on transfer sheet. Designed sticker is ready.


I used it on my laptop, one can use it in different things like jug or glass.

I also designed and cut few other stickers, I liked and enjoyed this process of sticker designing.



2. Laser cutting (press-fit construction based)

'Laser cutter' is a computer controlled machine and it uses a laser to cut the materials. In this week, for this machine, task was to construct a press fit product. For designing of this task, I used SolidWorks, Rhino 3D, and InkScape. I used different softwares because to finalize a software which I have to use for rest of assignments where needed. In last, I set my mind to work with SolidWorks, as it's a very powerful tool, no doubt Rhino is also good.

Press-Fit Construction is also known as friction-fit construction. There are few thumb of rules for press-fit construction kit:

For this task, I designed a simple open box using 'SolidWorks'. Snaps are given below:


But, I did not laser cut it, because I did this only for practice.

Again, I wanted to design a simple pen container box. For this, I used 'Rhinoceros 3D' software, which is non-parametric, to make it parametric we have to use 'grasshopper' which is 'visual programming language'. I installed 'Rhino 6' on my laptop. Then I tried to design the box, below snaps show my first sketch.

Connecting the pieces of the box


Bottom side of the box

Pen and pencils in the box, but top side is not connected well

Parametric design using SolidWorks

After experiencing it, I can say that SolidWorks is the best parametric CAD software. For fulfilling the basic requirement of this task, we have to laser cut a model which must be designed parametrically in any parametric CAD software like SolidWorks or Fusion360. I choose to design my model in SolidWorks.

For this, I visited the laser cut models of David Graas. And, selected following design.

This model is taken from the page of David Graas.


I started to design the model for myself, in SolidWorks. Few deigning process snaps are given below. My designed parametric model's files can be download from Here.

Designing process in SolidWorks by defining parameters in "Equations and global variables" in order to make the design parametric.


Fillet the corners to make then bit curvy for better look


Generated DXF files


Parametric variables for different parameters of the design.


Global variables are shown, this make my life easy.


Design is laser cut, total 24 parts are under use, by press fitting them we can achieve our final product.


Fitting the parts




Its very hard, I guess babies can sit on this table easily :P


Benefits observed by parametric design

Parametric design reduces the problems which occurs when we think to change the design parameters. take the my example, I designed it in SolidWorks by setting "global variables" of the parameters of the design. I choose 3 mm (0.118 in), because I thought to laser cut it on plywood of 3mm thickness which is available in our lab. When I complete my whole design, then I recognized that we have few sheets of 3mm plywood in our lab, in other hand I saw that we have 4mm (0.157 in) cardboard in abundant quantity. So, I set my mind to laser cut my design on cardboard. Here design needs to change from 3mm of thickness to 4mm. What I did, I just went to "Equations" and change the thickness from 3mm to 4mm in "global variables". This way, every where the design changed its thickness, and where ever I used this parameter it changed accordingly.

Learning outcomes and conclusion

Download all files from here

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