MATERIALS — FULL BOM
ITEMSPECUSESTATUS
Nylon monofilament0.1mm (label: 0.4), 120m rollAll fibers — both coarse + fine✓ SOURCED
Nichrome wireAWG34, 0.15mmCoarse fiber heater✓ SOURCED
Nichrome wireAWG40, 0.08mmFine fiber heater✓ SOURCED
Sewing threadThin polyesterFiber binder✓ SOURCED
PET braided sleeve4mm, 5mFascicle housing✓ SOURCED (purple/black)
Strong Elastic Crystal Beading Cord0.5mm elastic PET, 120mElastic tendon core✓ SOURCED
Kevlar threadAny braidTendons + ligaments✓ SOURCED
Mineral oil / silicone oilLight gradeFascicle cooling fluidFuture improvement
IRLZ34N MOSFETTO-220, N-channel logic-levelPer-fascicle PWM switch✓ SOURCED (10pcs)
1N4007 diode1A 1000V flybackBack-EMF protection✓ SOURCED (100pcs)
Ceramic capacitor104 (0.1µF), 50V, 100pcsDecoupling / noise✓ SOURCED
Electrolytic capacitor100µF, 16V, 50pcsBulk capacitance, filtering✓ SOURCED
Glass fuse 5×20mmSlow blow, 0.2–20A assortedCircuit protection✓ SOURCED (100pcs)
Glass fuse holder5×20mm, 15AFuse mounting✓ SOURCED (5pcs)
Fast wiring connectors2-pin with latch, 30pcsMuscle group connections✓ SOURCED
Tinned copper wire24 AWG, 5mPower bus wiring✓ SOURCED
3D-printed TPU skeletonMonolithic print-in-placeBones — full arm structureFuture build
TPU joints with PTFE coatDip in resin, polish, PTFE dry lubeLow-friction pivotsFuture build
Lab PSU30V / 10ADev + testingIn cart
ESP32Dev boardControlOwned
RESISTANCE + POWER TARGETS

COARSE FIBER (AWG34)

RESISTANCE / 10cm10–25Ω
AT 12V / 25Ω5.8W per strand
PWM RANGE40–100% duty cycle
CONTRACT TIME0.5–2 seconds
COOL TIME3–8s dry / 1–3s oiled

FINE FIBER (AWG40)

RESISTANCE / 10cm~40Ω
AT 12V / 40Ω3.6W — run at 20–30% PWM
PWM RANGE20–40% duty cycle
CONTRACT TIME~0.5 seconds
COOL TIME~1 second

POWER BUDGET — FULL ARM ESTIMATE

~50 FINE FIBERS @ 20% PWM~36W continuous baseline
~30 COARSE FIBERS IN GROUPS OF 5–10~30–90W burst
PEAK TOTAL ESTIMATE<200W — well within ATX 600W
CONTROL VOLTAGE12–24V DC
MOSFET TYPEN-channel, IRLZ44N or IRF540N