Week 05 Class Notes¶
2/18/2026 Scanning and 3D printing¶
https://fabacademy.org/2020/labs/ulb/students/quentin-bolsee/projects/samd21e_piano_piezo/ Uses piezoelectric touch sensor.
Use digitalWriteFast(pin, val) -fast, sends directly to the pin, no safety should there be a mistake Not digitalWrite(pin, high) - slow
Inigo Gutierrez Febles used capacitative circuits https://fabacademy.org/2026/labs/leon/students/inigo-gutierrez/ His final project uses stepper motor to raise and lower a desk.
9:24 Neil is impressed with the PIOs on rp processors. More versatile and customizable, because there are many little processors that you can program peripherals from.
RFC sensors for interactivity (interactive gameboard)
10:08 Neil cuts in to show code for displaying video on website
https://github.com/YouMakeTech/PicoRetroGamingSystem Codes for gaming
Lecture notes¶
3d Scanning¶
touch prob Coordinate measuring machine (cmm) Point clouds to polygons (triangles) Measurement from the probe includes the probe so you must subtract the probe
Scanning - binocular vision 3d by comparing the difference in images taken the same distance from the object (depth), but a slight distance from each other horizontally, the greater the difference the greater the distance from the observer. Mark a point on the object so that you can match up the points on the 2 images meshing/triangulating a solid (Poisson surface reconstruction) Enough points close together you can work out the normal angles to the surface in small triangles, and create the slopes of the object’s surface Creality CR-Scan Ferret Pro 3D Scanner Infrared scanner ~$300 Small, plugs into computer, can take color images as well Cameras must measure picosecond intervals to 3d scan Cellphone cameras are now able to do this!
File format¶
3d Printing¶
Additive process Not much waste Can do very complicated designs that would be very complicated to mill Can make complicated, interconnected objects in 1 one print (gears) (FFF) Fused Filament Fabrication is not a trademarked term, Fused Deposition Modeling (FDM) is trademarked Bambu uses this. Extrudes hot material onto previous layer (PLA is relatively safe, made from polymerized sugar, sometimes as titanium… added to make uv resistant) Materials release ultra-fine particles over time. VOCs
Infill Free-flow infill pattern allows you to pour liquid into the object to fill it up. Support Skirt - clears the nozzle before printing Brim - more contact to hold print in place Raft - prints under and around the print to level and help stick to plate Internal structure (11:40) Add cylinders randomly to act like fiberglass, and add strength Multi-filament print Different materials have different properties. Add a bendable material and a conductive material, or stiffer material PVA? - dissolves in water Meltable wax material for lost wax casting https://machinablewax.com/wax-filament/ Fitting 3D printed parts together Minkowski sum (the kerf of the 3d printer) Freecad incorporates this -OpenSCAD Smoothing print Can use a solvent to smooth lines on material, be careful Suspend object in a vapor chamber with solvent (acetone)
Stereolithography (SLA) -uses a laser to harden a resin that is cured by uv light -each layer rises when cured so that the printer is building from the top down SLA 3D is more precise but not as fast as pixelated … that pixelated the image by layer to cure each layer at one time. -must wear PPE, and follow a strict after print (post processing) workflow that washes the print, and cures it further.
Material Jetting- Multi material printing -prints multimaterial, and cures as it prints -allows a range of different material properties -used for surgery practice
The 3dPrinting Handbook