Week 05

This is my 5th week at FabAcademy. This week I have learnt a lot about 3D scanning and printing. The assignment of the week consisted of the following tasks:

group assignment: - test the design rules for your 3D printer(s) individual assignment: - design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively - 3D scan an object (and optionally print it)

Group assignment

Regarding the group assignment, along with my colleagues José Antonio Vázquez and Francisco Ruz, we were instructed about distinct tests that can be utilized for assessing the callibrations and performance of 3D printers. After discussing with my colleagues, we finally chose a very complete test that it is available here: https://www.thingiverse.com/thing:2656594#google_vignette. The test consists of a multiple 3D printing test in which bridging, hole, overhang and diamter test are all performed. The design was done by Marián Trpko3, see an illustration of the test in the following figure.

In oder to test it in our printers, we first installed the software Prusa Slicer which is a easy printing design platform for the Prusa printers, that allows for easily and fast configure the different parameters for printing and visualize the slicing of the different layers.

Once installed, my mate José Antonio Vázquez, who is really an expert on the topic, guided us about the differnt configurations and parameters up to generating the gcode necesssary for the printers to print. This whay I imported the stl file of the test and opened it on the prusa software. Then we changed the expert mode of the software to normal user and configured a draft/fast deafult configuration for printing PLA with 0.3 mm slicing. Here you can see the stl model after importining it in the Prusa software

Once, configurated the main parameters, the sofware automatically slices it and generates the gcode. You can see the different layers and visualize the fillings and operations necessary for the printer to manufacture the selected object. Here you can see the resulting slicing as well as the generated gcode.

Afterwards we proceeded with the printing in the prusa MK3 Plus along with the printing in the in-house printer. Here you can check out all the details of our group assignment: https://fabacademy.org/2025/labs/aindustriosa/week05.html

Individual assignment part A: design an object that cannot be printed by substraction

Regarding the individual assignment, I designed an icosaedron that it is contained inside a cube, which represents a clear example of object that cannot be printed by subsctraction. I accomplished the design in a parametric way in Grasshopper. First I tried to generate it directly by Python code, but some mistake happened that later on when exporting the stl file to the Prusa slicer did not happened. So I resorted to my colleague Jose Antonio who helped me to implement it with normal Grassshopper commands (not with Python), which worked nicely. The strategy for the design was generating the design was basically drawing the curves in Rhino and then using the pipe command see an illustration of the design process in Grasshopper here (you can download the file in the las section of this assignment):

This resulted in the following output geometry in Rhino

Then the icosaedron and cube files were backed in Rhino and were respectively exported into stl files to be then read in Prusa slicer. Here you can see the slicing of the geometry prior to printing in the Prusa slicer software:

And here you can see the result after printing:

After cutting and ammending some mistakes, the inside icosaedron could be moved respect to the surrounding cube:

Individual assignment part B: scan an object

Regarding the scanning part of the assignment, I dowloaded the Scaniverse app which allows for 3D scanning with smartphones even when the phone does not have lidar hardware, which is my case. This free software is available for both Android and Mac phones, here you can check and download the scanning software: https://scaniverse.com/. The software consists of a very easy-to use tool, in which the user just needs to scan an object from different angles after setting an approximate scanning depth. The scannig process takes about 4 minutes for a small object, like in my case one printed figure in the lab. Here you can see the figure I scanned during the scanning process:

Once scanned, a point cloud is generated which finalises with a mesh generation and subsequent export to stl file. Here you can see the point cloud generation process as well as the resulting scanned object.

Files for dowload and replication

Here you can download the important files of the week:

Grasshopper file of the non-substraction printing design Grasshopper

Stl files of the non-substraction file to be imported for printing Icosaedron Cube

Stl file of the scanned object: Scanning