adilkalam/print-prep

Print-Prep Skill

RULE: Never recommend a setting without explaining WHY and stating confidence level.

Hard Rules (Non-Negotiable)

1. Never apply settings without explaining WHY and stating confidence level (Empirical / Research consensus / Inferred)
2. Never recommend calibration values (K-value, flow rate, exact max volumetric speed) -- these MUST be calibrated per spool via Flow Dynamics and Flow Rate calibration
3. Never assume two spools behave identically -- even same brand/color can vary in diameter, moisture, and additive ratio. Always note spool-specific variables.
4. Never ignore model geometry when recommending speed/cooling -- a cylinder, a cube, and an organic sculpture respond differently to the same settings
5. Never recommend Proto-Pasta Steel/Brass PLA on P2S -- brass nozzle + abrasive filament = nozzle destruction. X1C with Diamondback only.
6. Always compute actual speed from max volumetric speed:

   actual_speed = max_vol / (layer_height * line_width)
   

   Flag if actual speed falls in VFA zone (70-170 mm/s). Show the math.

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MCP Tools Available

When working in the ~/3d-models project, Claude has direct access to bambu-3mf MCP tools for reading and writing 3MF files and presets.

Settings Tools (read/write 3MF files directly)

• list_presets -- Scan ~/3D-Models/_presets/ for available filament and process presets
• read_settings -- Extract print settings from a 3MF file or JSON preset. Returns project_settings and filament_settings.
• apply_preset -- Merge a preset JSON into a 3MF file at a specific filament slot. Creates backup.
• update_settings -- Surgical key-value override on a 3MF file. Creates backup.

Slicer Tools (require OrcaSlicer CLI)

• slice_analyze -- Run OrcaSlicer on a 3MF to get real time/weight/cost estimates
• slice_compare -- Compare multiple presets via actual slicing, get recommendation
• slice_batch -- Calculate batch production metrics (time/cost for N units)
• read_orca_config -- Read Orca_print.config XML metadata from 3MF (no CLI needed)

Tool Usage Rules

• When recommending settings, OFFER to apply them directly via update_settings or apply_preset instead of only giving manual Bambu Studio UI instructions.
• When the user asks "how long will this take" or "compare profiles", use slice_analyze / slice_compare for real data instead of guessing.
• Before recommending changes, use read_settings to check current state first.
• All write tools create .backup.3mf automatically -- safe to use.
• 6 gcode keys are NEVER modified (machine_start_gcode, machine_end_gcode, layer_change_gcode, before_layer_change_gcode, change_filament_gcode, template_custom_gcode) -- the MCP enforces this.
• If OrcaSlicer CLI is not available, slicer tools return helpful install instructions -- settings tools always work.

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Pre-Flight Assessment

Before recommending ANY print settings, assess these six questions. Do not skip any.

1. What filament? -- Determines base profile (silk, matte, standard, HTPLA, etc.)
2. What filament condition? -- When was it last dried? How long in AMS? Moisture degrades all PLA types.
3. What geometry? -- Overhangs (angle?), thin walls, tall/narrow, cylindrical, organic? Geometry changes cooling, wall order, and seam strategy.
4. What goal? -- Speed, quality, balanced, display piece, functional/structural?
5. What printer? -- P2S (brass nozzle, PMSM servo, adaptive airflow) vs X1C (Diamondback available, stepper extruder). Settings do NOT transfer between them.
6. What changed since last successful print? -- New spool? Different model? Settings adjustment? Environment change?

If the user does not provide this information, ask for it. Do not guess.

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Setting Interaction Web

Settings are coupled. Changing one without understanding the coupling produces failures. These are physical constraints, not preferences.

Temperature-Speed Coupling

Higher speed = less time in the melt zone = temperature must increase to compensate.

| Outer Wall Speed | Silk PLA Nozzle | Standard PLA Nozzle | Why | |------------------|-----------------|---------------------|-----| | 30-40 mm/s | 215-220C | 200-210C | Long dwell in melt zone | | 60-100 mm/s | 220-225C | 210-215C | Moderate dwell | | 200+ mm/s | 230-235C | 215-220C | Short dwell, needs more thermal energy |

If you change speed, flag that temperature may need adjustment. If you change temperature, note whether the speed profile is still compatible.

Nozzle material caveat: Brass (109 W/mK) is the P2S default. Diamondback (543 W/mK) delivers heat 4.7x more efficiently -- same speed works at 5-15C lower. Hardened steel (50 W/mK) needs 20-30C higher.

Cooling-Speed Coupling

Higher speed = less time between layers = cooling must increase.

For silk PLA: mica particles must be locked into reflective orientation by cooling. Insufficient cooling = matte patches.

| Outer Wall Speed | Silk PLA Fan | Standard/Matte PLA Fan | |------------------|--------------|------------------------| | 30-40 mm/s | 40-50% | 80-100% | | 200+ mm/s | 100% | 100% |

YouTube guides say 40% fan for silk because they assume 30-40mm/s. At 200mm/s on P2S, 100% constant fan is correct (Empirical).

Max Volumetric Speed -- The Real Speed Limiter

The slicer sets a requested speed, but the printer caps actual speed at the max volumetric limit:

actual_speed = min(requested_speed, max_vol / (layer_height * line_width))

Example of the VFA trap:

• Requested: 200 mm/s outer wall
• Max vol: 8 mm3/s
• Layer: 0.16mm, Width: 0.45mm
• Actual: 8 / (0.16 * 0.45) = 111 mm/s -- VFA zone (70-170 mm/s)

ALWAYS compute and show the actual speed. If it falls in VFA zone, say: "Your settings request Xmm/s but max volumetric limits actual speed to Ymm/s (VFA danger zone 70-170mm/s). Increase max vol to Zmm3/s to reach requested speed."

Infill/Wall Overlap -- Hidden Quality Killer for Silk

Silk PLA's mica particles amplify sub-surface infill patterns as visible shimmer disruption on outer walls. Discovered empirically.

| Filament Type | Safe Overlap | Why | |---------------|-------------|-----| | Silk/Glossy | 0-10% | Mica particles amplify sub-surface patterns. 25% default causes visible gyroid ghosting. | | Matte | 15-20% | Light-scattering surface hides infill ghosting | | Standard | 15-25% | Semi-glossy surface does not amplify patterns visibly |

For silk: default to 0% overlap. If user reports "wavy patterns on silk walls," infill overlap is the first diagnostic, not cooling or speed.

Tradeoff: Reducing overlap to 0% weakens infill-wall structural bond. Fine for decorative silk. Not acceptable for structural parts.

"Slow Down for Layer Cooling" -- The Print Time Bomb

When enabled, all moves slow to meet minimum layer time. Cascading effects:

• Inner wall speed drops from 300mm/s to 15-20mm/s
• Print time can explode (observed: 1hr to 5hr on a single model)
• Speed variation on outer walls creates gloss banding on silk

For silk PLA on P2S: Disable entirely. The 100% constant fan handles cooling. For matte/standard: Can leave on, but expect longer prints on small models.

Sub-setting: "Don't slow outer walls" -- exempts outer walls from slowdown. Only visible when parent toggle is ON.

Wall Order -- Model-Dependent, Not Universal

| Wall Order | Best For | Avoid When | |------------|----------|------------| | Outer/Inner (outer first) | Silk display pieces, simple geometry, dimensional accuracy | Steep overhangs >60 degrees | | Inner/Outer (inner first, DEFAULT) | Complex geometry, steep overhangs, general purpose | Surface quality paramount on simple shapes |

Do NOT globally set wall order. Analyze model geometry first.

Scarf Seams -- Geometry-Dependent

• Good for: cylindrical geometry, round features where seam visibility matters
• Poor for: angular geometry (cubes, hexagons -- seam visible on flat faces)
• Setting: Filament > Scarf Seam Type > Contour, Length 10mm

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Calibration Gating

What Can Be Set From Knowledge

These values can be recommended based on the master reference:

• Nozzle temperature range
• Fan speed
• Outer/inner wall speed
• Max volumetric speed (starting point)
• Layer height
• Flow ratio (starting point)
• Infill/wall overlap
• Wall order
• Seam strategy

What MUST Be Calibrated Per Spool

These values CANNOT be guessed. Recommend calibration, never a specific number:

• K-value (pressure advance) -- Flow Dynamics calibration. Different per filament AND per nozzle.
• Exact flow ratio -- Flow Rate calibration. Two spools of same filament can differ by 7%+.
• Exact max volumetric speed -- Validation print at intended speed. Apply 8-10% safety margin.

When to Recalibrate

| Trigger | What to Recalibrate | |---------|---------------------| | New spool (even same brand/color) | Flow Dynamics, Flow Rate | | Changed nozzle | Everything | | Nozzle temp changed by >10C | Flow Dynamics | | New filament type (first time) | Full calibration | | Quality degraded on known-good profile | Check moisture first, then recalibrate Flow Rate |

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Anti-Hallucination Guards

These Do NOT Exist in Bambu Studio -- Never Reference Them

• There is NO "Settings > Filament > Import" menu path
• There is NO "Preferences > Profiles" panel
• There is NO "Profile Manager" window
• There is NO drag-and-drop preset import
• There is NO "Apply Profile" button in the toolbar
• You CANNOT paste JSON settings into Bambu Studio directly
• There is NO command palette or search for settings

Note: While Bambu Studio has no "Apply Profile" button, Claude can apply presets directly to 3MF files via the bambu-3mf MCP (apply_preset and update_settings tools). This is NOT a Bambu Studio UI feature -- it modifies the 3MF file which Bambu Studio then reads.

When Uncertain About a UI Element

• Say "I'm not certain this menu path exists in your version of Bambu Studio -- please verify"
• Never fabricate a UI flow. If you do not know the exact path, describe the SETTING KEY and VALUE and let the user find it.
• Reference the master doc: ~/3D-Models/docs/bambu-studio-settings-master-reference.md

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When to Apply This Skill

ALWAYS apply when:

• User asks about 3D print settings for Bambu Studio
• User asks about filament recommendations or comparisons
• User is preparing a print (any filament, any printer)
• User reports a print quality issue (use interaction web for diagnosis)

Scale the overhead:

• Quick question ("what temp for silk?"): Answer from filament table in references/filament-data.md, note confidence level
• Full print prep ("set up this model for silk on P2S"): Full pre-flight assessment, load references/filament-data.md for complete profiles
• Troubleshooting ("wavy patterns on silk"): Use interaction web to diagnose

SKIP when:

• Non-3D-printing work
• OpenSCAD design work (different skill)
• General CAD/modeling questions unrelated to print settings

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Reference data: For filament profiles, Bambu Studio UX navigation, preset files, output format, pitfall catalog, and P2S hardware context, see skills/print-prep/references/filament-data.md. Load via Read tool when needed.