What we would buy, what is already here, and what is only a class estimate. Order now is the only authorized spend. Nothing below with an estimate is a chosen part.
V1 direction, 2026-09-27 (R37–R40, decisions.md): the finish line is one 9.5" step, 9 of 10 attempts from a standstill; flat-ground pace 1.5 m/s top / 1.0 cruise; knee RS02 at the knee with a gravity spring; V1 terrain is flat + 1" sills + ~20° slopes. Nothing on this page changes for it — the same eight actuators, pack and MCU. Layout: Sheet 1.
Order now~$230Tires, tubes, carbon tube, Teensy 4.1 CAN kit, XT90-S, 8S 3300 mAh pack. Shipping extra.
Later, class estimate~$1,400Actuators are most of it; shortlisted, none ordered.
Working total~$1,640Order now plus the estimates. Eight RobStride units are ~$1,200 of it.
Order now — ~$230: tires, tubes, tube, Teensy 4.1 CAN kit, anti-spark, 8S pack
Teensy 4.1 + ICM-42688-P IMU + 3× CAN transceivers
~$55
The CAN real-time MCU. Three CAN buses, microSD blackbox. Added 2026-09-26. Why three buses.
1
XT90-S anti-spark pair
~$5
Harness side. The pack keeps a plain XT90.
On hand — $0
Qty
Part
State
Role
1
F765-Wing
Bench
P0–P1 bench board: blink, CRSF, one wheel. No CAN, so not the robot's controller (2026-09-26). The robot's MCU is a CAN board (Teensy 4.1 / H743-WING class, ~$30–70), picked with the actuators, not bought. Software.
2
Gyros on the Wing
On the board
MPU6000 and ICM20602, on SPI. The balance loop reads these. The Pi does not.
1
TBS Nano RX
Unconfirmed reuse
Pilot link. TBS firmware, CRSF, into the Wing. No Hux code.
1
Raspberry Pi 5
Unconfirmed reuse
Raspberry Pi OS Lite. Listens to the Wing. Cameras, faces, and pathfinding later. Not required to balance.
0–1
ESP32
Unused
On hand. Nothing planned. The Pi already has Wi-Fi.
Shop and bench — not in the total
Qty
Part
State
Role
2
Wheel hub
Shop
Lathe and mill. Bead seat 3.75".
1 pair
Zantle 5" walker wheel
Bench
Not purchased; previous claim superseded. Not the foot.
GIM8108-8 is a yardstick, seen near $85. It is not an order and it is not in the total. Nominal 7.5 N·m is tight for the 9.5 N·m roll example at 6 kg on the 14 inch stance, and it is a 24–48 V class part. Superseded by the RobStride shortlist on 8S (2026-09-26).
Actuators — ~$1,200, shortlisted, not ordered
Qty
Part
Est.
Role
2
Wheel actuator — RobStride 05 shortlisted
~$200
5.5 N·m peak, 191 g, driver and encoder on board. Sets the pace: 1.5 m/s top, 1.0 cruise (R38) with ~2 N·m of catch left at 1.5 on the 6" wheel. Its 44 mm housing is 0.24" proud of the 1.25" tire on each face — hub drawing before any order. Not ordered.
2
Hip roll — RobStride 02, roll axes at 3.0" (Sheet 1)
~$340
6.3 N·m hold whenever a wheel is up at the 3.0" axes (frontal model), vs 7 rated; ~11 at the old 5.4". The shift then needs 2.8" of leg-length difference to stay level — a controls term. Not ordered.
4
Knee (RobStride 02) and hip swing (RobStride 00)
~$680
CAN QDD working class on an 8S bus. Servo / stepper+belt is the fallback. Not ordered.
Power
Qty
Part
Est.
Role
1
8S 3300 mAh 50–60C LiPo, XT90
~$80
Decided 2026-09-26, in the order-now list. XT90-S anti-spark on the harness. About 700 g. Needs an 8S-capable charger.
1
Step-down and distribution
~$20
Logic and pose off the motor rail. No board picked.
Cameras and face — ~$180, later
Qty
Part
Est.
Role
2
Front stereo pair
~$40
Part of the seven-camera estimate. No module picked.
5
Back, left, right, top, bottom
~$100
About $20 each. No module picked.
1
Preset-face display
~$20
About 2.2" × 1.0". No panel picked.
2
RGB in each eye socket
~$20
Shines into the orbital cavity. The light is the eye.