Bill of materials
Hardware is sourced separately from our $12 digital packs. Below are suppliers we’d use ourselves for the Animatronic Hand and future builds — local makerspaces first when you can, specialty electronics when you need reliability.
Why: Often the cheapest per seat for 3mm birch; you learn kerf and fit in person. Local makerspaces — often the best per-seat cost for birch.
Search for: “makerspace laser cutter near me,” Baltic birch 3mm sheet.
Ask your local library, Fab Lab, or school shop.
Why: Mail-order laser fab from DXF/SVG; strong STEM / education path. Mail-order laser fab from your DXF/SVG files; strong STEM / education path.
Search for: Upload pack cut files; 3mm birch / wood options per their materials list.
sendcutsend.comWhy: Long-standing SVG/DXF fab service; useful when a makerspace isn’t nearby.
Search for: Birch plywood / wood sheets matching 3mm design thickness.
ponoko.comWhy: Primary electronics source for serious / classroom BOMs — selection, datasheets, reliability.
Search for: Arduino Uno / ESP32 DevKit, Dupont jumpers, breadboards, 10k potentiometers, PCA9685.
digikey.comWhy: Education-friendly Arduino-adjacent boards, sensors, and tutorials.
Search for: RedBoard / Uno-compatible, Qwiic sensors, servo accessories.
sparkfun.comWhy: Trusted education electronics and learning resources.
Search for: Metro / Feather / ESP32 boards, servo drivers, STEM kits.
adafruit.comWhy: Broad component catalog for connectors, passives, and development boards.
Search for: Microcontrollers, headers, wire, educational Arduino kits.
newark.comWhy: Convenient for SG90 multi-packs, jumper assortments, AA holders. Prefer DigiKey / SparkFun / Adafruit first; disclose Associates if/when approved.
Search for: “SG90 micro servo 9g 5-pack,” Dupont jumper M-M M-F, 4×AA battery holder with switch.
amazon.comWhy: Spec-grade M2/M3 screws, locknuts, shoulder bolts — when you want exact hardware.
Search for: M2 / M3 socket or Phillips machine screws, nylon-insert locknuts, optional shoulder bolts.
mcmaster.comWhy: Convenient if you’re already ordering electronics; small packs of metric hardware.
Search for: M2 M3 screw assortments, hex nuts, standoffs.
digikey.comWhy: Fast for a weekend build; quality varies — check thread pitch and locknut fit on a scrap hinge first.
Search for: Metric machine screw kit M2–M3, nylock nuts.
amazon.comWhy: Braided fishing line / Spectra (10–20 lb) is the flexor material — low stretch is the point. Craft elastic is wrong.
Search for: “Spectra braided fishing line 10–20 lb,” zip ties, small beads for tendon stops.
amazon.comWhy: Wood glue or medium CA for non-pivoting bonds; painter’s tape for labeling tendons.
Search for: Wood glue, medium CA, masking tape — never glue a hinge closed.
Any reputable local store.
Why: M2/M3 hex or Phillips drivers and needle-nose pliers make locknuts and servo horns less painful.
Search for: Precision screwdriver set, needle-nose pliers, digital calipers (mm).
sparkfun.com · adafruit.comWhy: Free software for the pack sketch (Uno / ESP32 with library notes).
Search for: Arduino IDE download.
arduino.cc/en/softwareProduct links for five live packs — Animatronic Hand, Servo Expression Face, IR Tripwire Doorbell, Birch Differential Rover, and Gyro Leveling Platform. These are affiliate links (same disclosure as above). We still recommend DigiKey for classroom bulk and Amazon for cheap SG90 5-packs when that matches the BOM.
Packs: Hand · Face · Tripwire · Rover · Gyro
Select Arduino Uno in the IDE. SparkFun Original.
View on SparkFunPacks: Hand · Gyro
ESP32 path when the pack allows; use ESP32Servo / pack notes.
View on SparkFunPacks: Hand · Face · Gyro
SG90-class size. SparkFun unit price is higher than Amazon 5-packs — fine for one digit / classroom sample; commodity SG90 packs still OK for full Hand ×5.
View on SparkFunPacks: Hand · Face · Tripwire · Rover · Gyro
Breadboard / header wiring.
View on SparkFunPacks: Hand · Face · Tripwire · Rover · Gyro
Club / multi-pack builds.
View on SparkFunPacks: Hand · Tripwire · Rover · Gyro
Optional power / sensor layout.
View on SparkFunPacks: Hand · Face · Rover · Gyro
External 5 V-ish rail for motors/servos; share GND with MCU. Prefer a switched holder when available.
View on SparkFunPacks: Hand · Face · Tripwire · Rover · Gyro
For classic RedBoard (mini-B).
View on SparkFunPacks: Rover
Preferred dual DC driver for Birch Differential Rover.
View on SparkFunPacks: Gyro
SparkFun’s current IMU; pack docs still allow GY-521 / MPU-6050 clones. Treat as a capable substitute (library differs).
View on SparkFunPacks: Tripwire
Emitter for IR Tripwire Doorbell (pair with a phototransistor from DigiKey/Amazon; SparkFun detector SKU not linked yet).
View on SparkFunPacks: Hand
Optional finger-curl control.
View on SparkFunPacks: Hand
Optional cleaner multi-servo wiring / expansion.
View on SparkFunTypical hardware ~$42–148 depending on makerspace vs mail-order laser and whether you already own a controller. Digital pack is separate ($12).
Full verified BOM lives in the pack. Prefer DigiKey + makerspace/SendCutSend; use SparkFun cart picks for education boards; Amazon for commodity SG90 packs.
Integrity
We recommend suppliers we’d use ourselves. When a link earns a commission, it’s disclosed above — never at extra cost to you.
