Enclosure for mass production

[engmung]

Goal

A clean, strong enclosure that prints reliably at scale — moving from the split/glued
two-part design to a single-piece print on a larger bed, optimized for a 3D print farm
(PCBway prints + assembles for production).

Context / decisions

• Material: PLA (cost) or ABS (future)
• Production: 3D print farm at PCBway, printed + assembled there, scaling to dozens/hundreds.
• Support unavoidable but minimal, in non-cosmetic areas (removal = manual labor = cost).
• Vent holes (suggested) help cooling — also eases the thermal stress behind the PCB
  cold-joint failures (#).
• Laser-cut / acrylic / stainless versions: later, post-launch.

One-piece print

• Reorient for single-piece printing on the larger bed (no split, no glue)
• Minimize support; keep it in non-cosmetic areas
• Reduce warping: fillets on sharp corners, ribs under flat areas, uniform walls
• Add vent holes
• Confirm the board fits / stays serviceable

Snap-fits (two closing parts)

• Define the two joints (each needs its own snap-fit or slide)
• Parametrize clearance; print a tolerance ladder (0.10–0.30mm)
• Find a working range (not one point); re-test on more than one printer

Production handoff (PCBway)

• Write the print spec (material, layer height, walls, infill, orientation, post-processing)
• List critical dims + tolerances (snap-fit areas)
• Golden sample → inspect → approve → production run

Docs

• Add model files (STL + source) to repo
• Update build guide (settings, assembly, fitting the board)

[engmung]

test1

[engmung]

🔄 Update: Prototype Testing Results & Required Modifications (2026-06-24)

Just test-printed the revised one-piece enclosure. While the print quality is decent, we have several critical clearance, alignment, and print stability issues to fix before going into production.

---

1. Battery Slider Cover (Fitment Issue)

• Issue: The slider is loose and easily falls out. The current grooves/slots are too small to provide sufficient retention force.
• Fix: Increase the slider height by ~0.4mm and expand the slot/groove clearance to ensure a tighter lock.

---

2. Wire Routing Hole (Aesthetics & Alignment)

• Issue: The passthrough hole between the PCB and the battery compartment exposes the connection wires too directly, making it look messy. Minor tweaks to the current position won't solve this.
• Fix: Relocate the routing hole entirely in Blender to keep the cable management clean and hidden. (Still weighing options, but prioritizing relocation for now).

---

3. LED Matrix Back Cover (Floating Side)

• Issue: Since snap-fits were only implemented on one side, the opposite side is floating and lifting up. We need interlocking mechanisms on both sides.
• Testing Strategy: To save time and printing costs, I will not reprint the entire enclosure yet. I will slice and print small, isolated snap-fit joints, glue them onto this current prototype to verify the mechanism, and then update the master Blender file once confirmed.

---

4. Corner Warping & Lifting

• Issue: Experiencing classic thermal contraction/warping at the sharp corners, causing the edges to lift off the bed (as detailed in the Prusa Warping Guide).
• Strategy: I will try optimizing local slicer settings and bed adhesion first. If it keeps failing, we might have to print the enclosure vertically. (Note: PCBWay didn't have this issue with their previous run, so their production machines should handle it fine, but we need a reliable local test print first).

---

5. External Wall Artifacts / Layer Distortion

• Issue: A slight line/mismatch artifact appears on the outer wall, specifically starting at the layer where the internal structures/walls begin. This is likely due to uneven shrinkage between different wall thicknesses.
• Strategy: Adjust cooling settings and outer wall print speeds to minimize the artifact. Since past PCBway prints came out perfectly clean, this is likely a local printer tuning issue.

---

Next Steps

• Print small snap-fit test pieces and glue them to the enclosure for fitment validation.
• Relocate the wire routing hole in Blender.
• Adjust battery slider dimensions (+0.4mm) and groove depth.
• Tweak slicer settings to mitigate corner warping (or test vertical orientation).
• Optimize outer wall and cooling parameters to eliminate layer line artifacts.

[engmung]

Enclosure source iterated (commit 9d2c17c, branch dev): updated the Blender source (hardware/case/source/patternflow_v1.blend) and regenerated the one-shot experiment prints (hardware/case/print-ready/experiment/oneshot_test_{1,2}.stl), continuing the one-piece / rib work.

Status: print verification pending — keeping this open until a physical print is checked.

Still unresolved (not fixed in this pass):

• ⚠️ Warping / shrinkage on the flat areas → expecting to address this via slicing settings (not geometry) next.
• ⚠️ Visible layer lines on cosmetic faces.

So the "Reduce warping" checklist item is still open; the geometry side (ribs) is in, but the print-side tuning is the next step.

[engmung]

Anti-warp / seam pass on the one-piece print (commit bf6b8ca, dev)

Aimed at the warping + visible seam/lines. Geometry changes done; print check still pending.

Walls + corners — wall thickness 2mm → 3mm, and the outer corners rounded (fillet) only (inside left square). Thicker uniform walls + rounded outer corners should cut the corner-lift warping.

Snap-pins — added a small snap-pin on the slide joints (close-up of the shape):

Only 3 locations — deliberately kept low; more would make the two parts hard to seat. Should be enough to hold:

Slide joints — close-ups of the sliding pieces:

Next / still open

• Mouse-ear brims (anti-warp tabs at corners) — next.
• Warping + seam lines: geometry side addressed here; the rest is slicing-side tuning, to confirm on a real print.
• Snap-fit clearance: validate the 3-pin fit on an actual print (tolerance still untested).