2D cut - Laser and Vinyl

At the time we had have this assignment, the Epilog Mini was broke in our lab. Rhyzos Lab hosted us (from Insper) in order to achieve and finish this week tasks (as listed below). I learned that networking and helping each other inside the web is importand and brings better results on projects development for everybody. Once a lab is willing to share information and infrastructure with other labs, its power of improvement multiplies. After the laser cut machine maintenance was done, I could finish some extra work at our lab. Right now, we have two machines and a basic tutorial available.

The tasks asked are:

- Make lasercutter test part(s), varying slot dimensions using parametric functions, testing your laser kerf & cutting settings (group project).
- Cut something on the vinylcutter
- Design, make, and document a parametric press-fit construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways

Class material: Computer-Controlled Cutting

Equipment listed below:

Insper FabLab's operational manual here.

Epilog Mini - laser machine - tutorial01; tutorial02 and turorial03.
DuploTech - laser machine - software tutorial; user operation tutorial and machine download manual.
Roland GX-24 - vinyl machine - begginers tutorial and laptop decal tutorial.

Materials:

Cardboard - singlewave - 3,00 [mm] thickness.
Paper (paraná-paper) - color is not relevant - 3,00 [mm] thickness.
Vinyl sticker - 400 [mm] x 300 [mm] - color of your choice.

Group assignment - laser cut

Fusion360 design file here.

I refer to Victor Macusl's documentation for this topic. The link is here. In his webpage there is a description of our job and pictures of what we've made over there and Rhyzos lab.

Below, I will show some images of my part of group work. I made the design in Fusion360 of assembling parts to be cut in cardboard. Those parts had a variation in its dimensions and also the edges had two different formats. The idea of having this sample of small differences was to test assembling quality.

We learned that a good assembling quality would have a kerf (as you see in Kerf, the width of a saw cut) compensation to fit one part into another and also a choice of edges that makes easy to put parts togheter without braking anything.

Finally, we've learned that cardboar wave orientation over the cut format has an impressive influence. The parts mechanical resistence changes dramatically. So, for each application, I suggest to prototype different cardboards orientations to measure the one witch is going to present the best performance.

Software development - Fusion360. To have full access to design measurements and way of prototyping, please check sketch01 and sketch02. For a full check with Fusion360, the file would be here.

Creating gcode to laser cutter machine - LaserCad - 1.

Creating gcode to laser cutter machine - LaserCad - 2.

Extra information for this group assignment:

- Machine available at Ryhsos: Laser Cutter ecnc (Made in Brasil);
- Machine speed = 200 mm/s;
- Machine power level (min;max) = 50%; 50%.

Vinyl cut:

I made a strange profile drawing free hand in the cumputer. After that I stick it to my notebook. It was challenging 'cause I had problems with machine driver when installing it to my windows10 notebook. I borowed a lab computer to cut the vinyl. I choosed yellow collor and I think the result was nice.

Revisiting Vinyl Cut I had some time to remember how it works. I made de design with InkScape (you'll find more about this software in exercise02) and save it as pdf - that you can access here.

The vinyl sticker material is sold in rolls. But, as you work with it, it might happen that you end up with a piece left from a cutting work. Save each piece in a nice shape for smaller works (if you have space to keep those).

The process I had to do was "print" the pdf file with the lines I had designed. For this to work, there is the need to install the vinyl cut machine as a printer in the computer you have available. There will be an image bellow that shows Roland GX-24 and printer selected and also that you may "get from machine" the information of width and lengh of your material.

Software development - Inkscape.

Notebook yelow decor. For this to happend...
1) I removed from the sticker what I need to and only left the lines of interest.
2) I glued the yellow lines sticker in a transfer sticker (transparent and weak adhesive).
3) After that, I glued the transfer sticker over the computer and removed it. What was left was the lines it the right position.

This is the 'printer select' main screen + 'Properties' small form.
1) Choose Roland GX-24 as printer.
2) Click 'Properties'.
3) Click the button: 'Get from Machine'.
4) Observe if the sizes are the same in this form and also in the preview image.
5) Click 'Print'.

Laser cut - PressFit:

Fusion360 design file Press-fit.

This task was interesting. The challenge was to create a design that was parametric and had a shape which allowed assembling in different ways and structures. Material was cardboard 3,00 mm thickness as said above.

As the images will show, I made two different modules and cut a lot of them. In this way, I could try different assembled structures and have some fun creating objects.

The parametric design was handy once I needed to cut parts more than once, adjusting the laser machine and kerf interference. After analysing the inicial parts, I could make small changes in the parameter and propagate it over the whole set of designed parts (edges and surfaces).

The small parts drop to laser cut's waste box below its 'grill'. In a way to preserve your work, I suggest cleaning the waste box before starting it. So, if some parts fall off the cuting cardboard, they are easely recovered.

Sketching the pressfit models.

Software development - Fusion360. Everytime you read a value after "fx:" it means this value is linked into a function of x. Or it assures you that this design has parameters set. The image shows parameters defined to straight lines and fillets.

Sketching the pressfit models with Fusion360.

This is the parameters table. This is de place where to define parameters values and relations. I create two parameters, L (as in lengh) and Kerf (for laser cut kerf impact).
I measured the cardboard thickness and instead of 3,00 mm (material specification) it was 2,80 mm. So, the L constant is atributted 2,80 mm as value. This constant defines the size of the holes each pressfit part will have and is important it matches the same valeu as the material thickness (to 'fit' properly).

Sketching the pressfit models with Fusion360 and saving a copy as dxf.

After the same set of pressfit parts, It was noticed the Kerf attributed inicialy as to small (0,025 mm) and I had to adjust the value to 0,50 mm.

This is the last setup for this pressfit exercise. Kerf = 1,00 mm. Below you have images of laser cutting process and an object assembled with these pressfit parts. The Kerf parameter adjustment is key for this pressfit kit work properly.

This is the dxf file seen from the LaserWorks V8 CAD/CAM software (extra tutorial click here).
1) Select the lines you need to cut.
2) Select the same colour at the right side software panel. Choose the setup you need for cutting (values are shown in the next image).
3) Click 'Go Scale' to check if the laser cuting area is right above the material to cut.
4) Download files: Pressfit01; Pressfit02; Pressfit03; Pressfit04.

This is the laser cut machine panel.
1) Click the arrows to move laser head.
2) Select the Origin point to the laser machine and press the button 'Origin'.
3) Check the focus of your laer head with laser point or a presset object.

Laser cut experience, different tests and a lot of pressfit sets in the same cardboard area. I was changing origin preset and cutting it many times untill I get a good setup as the values I showed before for L and Kerf and also for the laser cut speed and power.

This is the object assembled as demonstration of pressfit possibilities.

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