Hardware Prototype Timeline

flux

The enclosure revision failed as a verification artifact, not necessarily because the overall v2c enclosure concept is wrong. The generated views were not reliable enough to prove that the selected parts, cables, and service motions physically fit, so I did not use them to authorize PCB changes.
What is resolved
The UI architecture is now clear:
  • The OLED and pushable encoder will share J9’s 3V3, GND, I2C_SDA, and I2C_SCL.
  • A smart I²C encoder avoids adding raw encoder A/B/push connections to the PCB.
  • The approved visual direction remains the screw-joined translucent enclosure with exposed controls, a guarded tube hatch, and a removable rear panel.
What remains unresolved
  1. OLED mounting
    • The candidate OLED PCB is about 29.2 × 26.7 mm.
    • The existing 36 × 24 mm opening is too large to retain it directly.
    • It therefore needs a carrier or bezel with verified screw locations, display alignment, panel thickness, and cable clearance.
    • That bezel would be visible, so it must be shown accurately before changing the detailed enclosure.
  2. Encoder mounting
    • The encoder electronics are suitable in principle, but the complete mechanical stack is not qualified.
    • We need to verify the threaded bushing, washers and nut, panel opening, 3 mm panel thickness, remaining shaft length, knob engagement, and push-button travel.
    • Without this, the knob might rub the panel, sit too far out, or lose its push function.
  3. Rear power inlet
    • A specific threaded panel-mount DC jack still needs to be fixed.
    • Its cutout, anti-rotation feature, nut clearance, solder-terminal depth, plug overmold, cable bend radius, and disconnect arrangement must fit the removable rear panel.
    • Rear-panel removal must not pull directly on solder joints or require cutting wires.
  4. Heater and thermal wiring
    • The heater block and tube holder are custom mechanical assemblies, not components already represented on the PCB.
    • The exact heater cartridge, block dimensions, thermal cutoff mounting, NTC packaging, thermocouple junction, strain relief, and thermal isolation still need qualification.
    • The proposed fine thermocouple wire is not directly compatible with the existing JST-XH contact range, which expects substantially larger conductors. A mechanically sound transition is required.
  5. Cable and service sweeps
    • We have not yet demonstrated that all plugs can be inserted and removed.
    • Cable bends must avoid the PCB, supports, hatch, optical chamber, and hot surfaces.
    • The rear panel must be removable with sufficient service slack.
    • The PCB/base assembly must remain removable without trapping the UI, power, heater, or sensor harnesses.
Why PCB routing is still on hold
The connector positions determine where the harnesses enter the enclosure and how much bend space they require. If one of those connectors needs to move after routing cleanup, the newly routed copper may need to be discarded.
Once those positions are mechanically frozen, I can make a surgical cleanup around U5, R9, R10, and D4 while preserving unrelated copper. That work will particularly address the wide HEATER_LOW_SIDE trace passing R10 with only about 0.36 mm local copper separation. It technically passes the present clearance rule, but it is poor margin in a noisy switching area.
So the current status is: the electrical UI strategy is selected, but the exact mounting and harness geometry are not yet proven. The PCB has deliberately been left unchanged until that proof is available.
G

greg

what's the next step?

flux

The next step is to finish the mechanical harness package before touching PCB routing:
  1. Select exact OLED mounting hardware/bezel, encoder mounting stack, and panel-mount DC jack.
  2. Define the heater block, cartridge heater, thermal cutoff, NTC, thermocouple transition, connectors, and strain relief.
  3. Update the approved v2c enclosure with those exact geometries.
  4. Verify plug insertion, cable bends, rear-panel withdrawal, and base removal.
  5. Freeze connector positions.
  6. Then clean only the U5/R9/R10/D4 switching area and rerun DRC/airwire checks.
The immediate actionable item is exact part selection and dimensioned mechanical modeling for the UI, power inlet, and heater assembly.

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