Hardware Reference

Summary¶

The Hardware Reference is the component-level technical reference for libdrone Pro V2.4.6: frame architecture, printed parts specification, floating motor mount system, electronics layout on the Platform, connectors and wiring topology, propeller selection, environmental reliability, and mass budget. It is the 3.0.0 replacement for the V2.4.6 Hardware Reference document — with all specifications delegated to atoms and the structure providing navigation.

Concept¶

Architecture summary¶

libdrone Pro V2.4.6 is a 330mm True-X quadrotor with a five-layer PETG-PCCF-PCCF-PCCF-PETG sandwich body on four 2.0mm CF rods, four PETG arm shafts with T-lock attachment, and a sealed PETG Platform layer on top that carries the electronics and payload interface. → sandwich-structure explains the composite logic. → cf-rod-architecture explains the rod pre-tension system.

The body is not the drone — the body is the chassis that other systems mount to. The key insight of the V2.4.6 architecture: the electronics (FC, ESC, VTX, GPS, receiver) mount to the sealed Platform layer, not to the sandwich. The sandwich and Platform are separate; the Platform can be replaced without touching the sandwich.

Printed parts¶

The structural printed parts and their key geometry requirements are owned by their respective atoms:

Arm shaft: → arm-shaft — T-lock profile, rod channel, pinch slit, dovetail groove on bottom face for motor wire routing
Arm tab: geometry defined by T-slot variables; mates arm shaft to PCCF layers
PCCF X-body layers (3×): T-slots, rod channels, stack holes
PETG top/bottom layers: rod channels, battery slot, foam pads
Platform: three-zone wiring channels, MIPI centreline, GX12 chimneys, fan slot, battery rail — → power-signal-separation for the EMC geometry gates
Backplane: Pi bay (LCM-1 ready), payload boss pads, fan mounting
GPS/camera bracket: MIPI channel, camera slot, GPS mount above camera
Bumpers (ASA): energy absorption at first impact point

All printed parts carry version numbers in the FreeCAD parametric model. → variable-table-values is the single source of truth for all dimensions.

Floating motor mount system¶

→ floating-motor-mounts covers the complete system: O-ring specification (ID 4.0mm, OD 7.0mm, CS 1.5mm, 40–50 Shore A silicone), sleeve specification, assembly torque (0.4–0.5 N·m, cross-pattern), Super Lube 52004 lubrication, and the passive cover clearance verification.

The isolation system is the most maintenance-critical component in the build. → scheduled-maintenance defines the replacement intervals. → vibration-isolation-theory explains the physics that makes it effective.

Electronics layout — Platform nose-to-tail¶

The Platform layer carries all electronics on a single plane. The Y-axis positions (measured from body centre, Y+ = nose):

GPS/camera bracket: nose (+50mm)
ELRS receiver: +15 to +40mm, LEFT channel
FC/ESC stack: centreline around Y=0
GX12 connectors A+B: Y = −66mm (paired, X = ±25mm)
VTX: −104 to −133mm electronics zone
Fan: rear face slot
Battery rail: Y = −39mm to −148mm, RIGHT side exit

All electronics positions are fixed by the Platform geometry — they are not configurable. The Platform is the printed wiring board of the libdrone architecture. → power-signal-separation explains the three-zone wire routing that the Platform enforces physically.

Connectors and wiring topology¶

→ gx12-connector-standard covers the dual GX12-7 payload interface. → sk-wiring-reference covers the complete wiring topology with gauge specifications and routing rules. The critical connector types:

XT60: battery to ESC — 12–14 AWG, twisted pair
MR30: ESC to motors — pre-soldered pigtails, twist 3 phases per motor
JST-SH 4-pin: companion harness (LCM-1 Pi bay to FC UART6)
GX12-7: dual payload connectors — permanent panel mount, D-D bore

Propeller selection¶

→ propellers covers the physics and selection criteria. The V2.4.6 standard propellers:

HQProp 6×3×3 PC tri-blade: standard set. Higher pitch, better performance in wind, standard mapping profile.
HQProp 6×2.5×3 PC tri-blade: low-pitch alternate. Calm conditions, maximum flight time, lower motor temperature.
M5 flange nuts: CW and CCW pairs for 5mm shaft. Required — standard M5 nuts will undo in flight.

Rate Profile 1 is tuned for 6×3×3; Rate Profile 2 for 6×2.5×3. → betaflight-profiles covers the profile switching procedure.

Environmental reliability¶

→ conformal-coating covers the moisture protection application. The V2.4.6 addition: the Thermal Retention Shroud (TRS) changes the coating specification from permanent silicone to reworkable acrylic — → thermal-retention-shroud explains why.

→ thermal-management-cooling covers the Gdstime 3010 fan specification and always-on cooling strategy. → winter-protocol covers the sub-5°C operational constraints.

Mass budget¶

The target and gate masses are defined in → variable-table-values. They change with configuration. The acceptance rule: if any mass target is missed, investigate before maiden. Mass misses are usually wire routing issues, unexpected component weights, or bracket geometry changes — all of which have implications beyond just weight.

Reference¶

Component substitution guide¶

All critical components have documented alternatives. The substitution rule: if the specified component is unavailable, consult → design-rationale-index to understand which properties of the component are critical before selecting a substitute.

Component	Critical properties	Substitution risk
Matek H7A3-SLIM FC	H7 class, 6 UARTs, IMU moat	Medium — any BF-supported H7 board may work
Pilotix 75A AM32 ESC	AM32 firmware, BiDShot, 6S	Low — any AM32 4-in-1 6S unit
O-rings ID4/OD7/CS1.5	40–50 Shore A silicone	High — shore hardness is critical
CF rods 2.0mm	±0.05mm tolerance	Medium — verify diameter with calipers
Panasonic FM 1000µF cap	ESR <0.1Ω at 100kHz	High — generic electrolytics fail this

Procedure¶