part 0: about the course

• emphasis
  • more "how"; less "why"
    • very little theory
    • lots of hands-on ("hobbyist") work
    • the "why" is also cool!--it's just not going to be our focus
  • more digital fabrication; less robotics
    • robotics is also cool!--it's just not going to be our focus
  • tools and techniques you can keep using after the course
    • the printing & cutting services we'll use are cheap and accessible
    • a great 3D-printer (BambuLab A1) is under $500 (NOT $50,000)
    • most software we will use is free (besides, unfortunately, SolidWorks; but OnShape is pretty accessible)
    • code has very few dependencies
  • fundamentals
    • projects will have only minimal starter code
    • projects may not always be "flashy" (our robots will have fewer features than most LEGO robots)

---

• lectures
  • tuesday lecture will be live math-ing/coding/CADing and is mandatory
  • thursday lecture will be fun (ethics, current events, a paper, guest lecture, etc.) and is optional

---

• homework
  • homework will primarily involve making stuff
  • you may also need to do reading and write summaries

---

• lab
  • lab is time for you to...
    • learn specific tools/techniques (3D-printing, soldering) in a supervised setting
    • work on the homework
  • you are expected to have read and started the homework before lab

---

• learning goals
  • how to write straight-forward, relatively-fast, flexible ("boring") code
    • arrays are the one true data structure
    • "plain old data" structs (no constructors, no inheritance)
    • for loops (using an index; using a pointer)
    • "staight shot through main" (helper functions better actually help us with something)
  • how to create straight-forward, functional ("boring") geometry (2D and 3D)
    • in code (exporting DXF; importing & exporting STL)
    • using CAD software (LAYOUT, SolidWorks, ZBrush??)
    • programmatically (Manifold / OpenSCAD)
  • how to fabricate geometry
    • 3D-printer (by self; via online service)
    • water jet / lasercutter (by self; via online service)
  • how to make a machine
    • adding threads (tapping, press-fit nut, T-slot nut)
    • bearings
  • how to make a circuit board
    • bread-boarding
  • how to make a robot

---

• how to succeed in the course
  • be willing to draw (and bring paper and pencil!)
  • be willing to do repetitive ("boring") work
  • be willing to ask questions (not asking questions about machines when uncertain is physically dangerous; you must ask questions in you're unsure what you're doing)
  • have zero or more prior experience with digital fab or robotics
  • know C or be willing to learn it quickly
    • we will call malloc/calloc, memcpy, fopen&fclose, printf/sprintf/fprintf like they're our bff's
    • we will make struct's; lots and lots of boring struct's (STL stl = {};)
    • we will use pointers (&array[i]/array + i, ...)
  • expect to spend 10-15+ hours per week on homework
  • start homework early if you intend to finish it 🙂👍

topic: mechanical

notes: from material to machine

• material is metal or plastic
• manufacturing (fabrication) means turning raw material into a part
• a machine is made from parts
• a machine tool (3D-printer, water jet, mill, lathe, drill press, broach, brake) is a machine for making other parts and machines
• additive manufacturing means adding material (glue gun, laying bricks, 3D-printer)]
• subtractive manufacturing (machining) means removing (cutting) material (scissors, mill, lathe, water jet)
• assembly means putting different parts together (into a machine)

homework: load a DXF

• do NOT try to parse the entirety of the DXF spec; just parse one of these (thank you John Burkardt)

homework: load and save an STL https://ozeki.hu/p_1116-sample-stl-files-you-can-use-for-testing.html

the power of digital manufacturing (from geometry to part)

• geometry is the shape of a part
• modeling means creating geometry on the computer
• DXF is a file format for 2D geometry
• STL is a file format for 3D geometry
• CNC (computer numerical control) is a class of machine tools that are controlled by a computer
• G-code is a programming language for CNC machines
  • G-code is typically produced (semi-)automatically from geometry
• ✨ if we can model it, we can build it

3 TODO: designs, solidworks, layout, slicer, * CAD (computer-aided design) is the use of compute

2D

3D

Cheat Sheet

• Bambu Studio
  • if you have overhangs, don't forget to Enable support
• Layout
  • a reasonable hole for tapping an M3 screw is 2.5mm
  • a reasonable through-hole for an M3 screw is 3.4mm
  • a reasonable through-hole for the head of a socket cap M3 screw is 6mm
  • a reasonable wall thickness for PLA is 2.0mm
  • don't forget to Clean your sketch at the end! (removes duplicate lines, etc.)
• KiCad
  • mashing escape can be helpful to deselect things
  • SMT is surface-mount; THT is through-hole
  • have to double-click to assign footprint
  • Inspect -> Measure Tool
  • Insert on Mac is Fn + Enter
  • double-click to finish drawing a line
  • the cross section of the switch pins is a rectangle (pythagorean theorem let's goooo)
  • F is front; B is back
  • (pcb) if you get something off grid, you can use M to move it back on
• Soldering
  • use right gauge of wire for stripping or else the wire will break when you use it
  • be very fast (and not too hot) when soldering to the switch or you will 100% melt it
  • WASH YOUR HANDS after soldering (do NOT touch your mouth)
• LED circuit through-hole PCB
• LED circuit surface-mount PCB

2d cutting

(one project that goes through all the techniques would be good)

wheels?

OMAX LAYOUT

building a box with standoffs sounds cool

add some motors?

vinyl cutting

some surface finishing

? silicone casting

T-nuts https://www.instructables.com/How-to-Build-your-Everything-Really-Really-Fast/

maybe a lamp?

• water jetting

• standoffs

• deburring tool

• tapping

• reaming / press fitting ?

3d printing

solidworks square nut press fitting teardrop shapes

✨ OpenScape + ShapeWays for "impossible print" (powder bed)

motors

sensors