Assembly & Wiring

Stub — section skeleton authored 2026-06-27; prose to follow.

4.1 Assembly Sequence Overview

This section presents the recommended assembly sequence for the complete DFCD build. Because the sliding screen mechanism constrains how cables can be routed and the drag-chain must be assembled before the chassis closes, the order of operations matters more than in a static enclosure. The section gives a high-level ordering before each subsequent section goes into detail.

4.2 Screen and Keyboard Slider Mechanism

4.2.1 Rail Assembly

The sliding screen rail allows the display to travel vertically or horizontally [VERIFY direction of travel from build video] over the keyboard, concealing it during transport and exposing it during use. This section covers the rail component assembly, the lubrication or friction treatment required for consistent slide action, and the travel stops.

4.2.2 Display Mounting

The 10.1-inch IPS LCD is mounted in the sliding panel. This section covers the panel retention, the cable routing through the sliding joint (including how the display ribbon cable enters the drag-chain), and the touch digitiser connection.

4.2.3 Keyboard Installation

The NOS 450 TKL keyboard is installed in the stationary lower deck. This section covers the keyboard’s USB cable routing to the Pi 5 and the physical clearance between the keyboard top and the underside of the sliding display panel in the closed position.

4.3 Trackball Module

4.3.1 Harvested Electronics Installation

The trackball electronics harvested from the Logitech Marble are mounted in the DFCD’s right-side trackball module. This section covers the harvest procedure (opening the Marble, extracting the PCB and sensor), the fit of the harvested assembly in the DFCD module, and the USB cable routing to the Pi 5.

4.3.2 Trackball Calibration

After installation, the trackball sensor may require configuration for the specific ball size and surface used in the DFCD. This section covers the OS-level trackball configuration (sensitivity, scroll emulation if used) and cross-references Vol 6 for software setup.

4.4 Power Path

4.4.1 NP-F Battery Integration

The NP-F battery pack mounts in the battery bay. This section covers the battery contact interface to the Joy-it step-down module, the retention mechanism that holds the battery in place during transport, and the polarity verification required before first power-on.

4.4.2 Joy-it Step-Down Module Mounting

The step-down module converts 7.2 V from the NP-F battery to 5.1 V for the Pi 5. This section covers the module’s mounting position in the chassis, the input and output wiring, and the output voltage verification step before connecting to the Pi 5.

4.4.3 Pi 5 Power Connection

The Pi 5 receives 5.1 V via its USB-C power input or via the GPIO 5 V pins [VERIFY which the reference build uses]. This section covers the wiring from the step-down module output to the Pi 5, including cable gauge and connector selection.

4.5 Rear USB Power and Signal Rails

The rear USB rails provide power and signal connectivity to modules that are mechanically docked to the chassis. This section covers the rail connector types (the 0B and 2B self-locking connectors and Y2M connectors from the BOM), the wiring from the Pi 5’s USB ports to the rail connectors, and the current capacity available to docked modules.

4.6 Controls and Indicators

4.6.1 Rotary Encoder Wiring

The rotary encoder with click function connects to the Pi 5 via GPIO [VERIFY pinout]. This section covers the wiring, the pull-up resistor requirements [VERIFY], and cross-references Vol 6 for the OS-level input event configuration.

4.6.2 Switch Wiring

The momentary switches (16 mm ×3, 12 mm ×1), tactile buttons (×10), toggle switches (×2), and slide switch each connect to GPIO or to the power path. This section covers the wiring for each control, distinguishing between those connected to GPIO (software-addressable) and those wired directly into the power circuit.

4.6.3 LED Wiring

Four 3 mm LEDs provide status indication. This section covers the LED wiring, the current-limiting resistor values [VERIFY], and the function each LED indicates.

4.7 Shoulder-Strap Mounts

The shoulder-strap mounts are structural features of the chassis with defined attachment points. This section covers the hardware that attaches to the mounts (swivel rings, D-rings, or similar [VERIFY]) and the strap configuration for comfortable single-shoulder carry.

4.8 Drag-Chain Cable Management

4.8.1 Cable Bundle Assembly

The drag-chain routes the cables that must flex as the screen slides: the display ribbon cable and any other wiring crossing the sliding joint. This section covers what goes into the drag-chain bundle and how the cables are supported at the entry and exit points.

4.8.2 Chain Installation

The drag-chain attaches to the sliding screen panel at one end and to the fixed chassis at the other. This section covers the end bracket attachment and the chain link count required to accommodate the full travel range without binding.

4.9 Connector Assembly

The 0B self-locking circular connectors, 2B self-locking connector, Y2M 8-pin connectors, and pogo pins each require crimping or soldering before installation. This section covers the assembly procedure for each connector type, the pinout assignments [VERIFY from upstream wiring documentation], and the locking/mating procedure.

4.10 Final Checks Before First Power-On

Before applying power for the first time, a set of verification steps reduces the risk of damaging the Pi 5 or other components. This section covers the mandatory checks: NP-F battery polarity, step-down output voltage verification at the Pi 5 power input, USB connections verified before the Pi 5 is installed, and the sliding screen travel check with cables routed.