PETG stringing at 200mm/s is almost always a temperature + travel speed
issue, not a retraction issue — which explains why bumping retraction did nothing.

1. Nozzle temp too high (most likely)
   240°C is on the hot end for PETG. At that temp, the melt pool stays
   liquid long enough to ooze during travel. Drop to 230-235°C and test.

2. Travel speed too slow
   At 200mm/s print speed, travel should be 250-300mm/s minimum.
   Check OrcaSlicer → Speed → Travel. Faster travel = shorter window
   for ooze to form strings.

3. "Avoid crossing perimeters" disabled
   Enable this in OrcaSlicer. It routes travels through the model
   interior — any stringing gets clipped rather than visible on the surface.

4. Wipe on retract not configured
   Enable "Wipe while retracting" in OrcaSlicer, set wipe distance to 2mm.
   This sweeps residual material back into the perimeter before the travel move.

Fix in this order: temp first, travel speed second. Those two alone will
resolve most PETG stringing on the K1 Max without touching retraction further.

Corner lifting on PLA with a textured PEI plate is usually a combination
of bed surface condition and first-layer squish, not just temperature.

1. Clean the PEI plate (most common cause that gets overlooked)
   Oils from fingers degrade PEI adhesion significantly. Wipe with
   isopropyl alcohol (90%+) and let it fully dry before the next print.
   Do this even if the plate "looks clean."

2. First layer squish too low
   In Bambu Studio, try increasing first layer line width to 120% or
   adding a -0.02mm to -0.05mm Z-offset adjustment. More squish means
   more contact area on corners.

3. Brim — the quickest fix for this specific problem
   Add a 5mm brim in Bambu Studio. For large flat parts with lifting
   corners, a brim eliminates the problem entirely. Remove with a
   flush cutter after printing.

4. Draft shield / enclosure draft
   If your X1C door is open and there is airflow across the bed,
   the corners cool faster than the centre and curl up. Keep the door
   and top closed for PLA, especially on large footprints.

IPA clean + brim will fix this immediately. The squish adjustment
is a good long-term calibration to make regardless.

G28                          ; Home all axes
M190 S{material_bed_temperature_layer_0}  ; Wait for bed temp
M104 S{material_print_temperature_layer_0} ; Start nozzle heating (no wait yet)
G29                          ; Run ABL mesh / load compensation
M109 S{material_print_temperature_layer_0} ; Now wait for nozzle temp

G92 E0                       ; Reset extruder
G1 Z0.3 F3000                ; Lower to first layer height
G1 X1 Y20 F9000              ; Move to purge start (left edge)
G1 X1 Y200 E14 F1200         ; Extrude purge line up the left side
G1 E-0.5 F3000               ; Retract slightly
G1 X4 F9000                  ; Wipe nozzle sideways
G92 E0                       ; Reset extruder before print starts

G91                          ; Relative positioning
G1 E-5 F3000                 ; Retract 5mm to prevent ooze
G1 Z10 F3000                 ; Raise Z 10mm (relative)
G90                          ; Back to absolute positioning
G1 X110 Y215 F9000           ; Park nozzle centre-back
M104 S0                      ; Turn off nozzle heater
M140 S0                      ; Turn off bed heater
M106 S0                      ; Turn off part cooling fan
M84 S120                     ; Disable steppers after 120 seconds

[gcode_macro START_PRINT]
description: Standard start macro with variable temp passing
gcode:
    {% set BED_TEMP = params.BED_TEMP|default(60)|float %}
    {% set EXTRUDER_TEMP = params.EXTRUDER_TEMP|default(200)|float %}

    # Home if needed (skips re-homing if already done this session)
    {% if "xyz" not in printer.toolhead.homed_axes %}
        G28
    {% endif %}

    # Heat bed first, nozzle to standby only (prevents ooze during bed wait)
    M140 S{BED_TEMP}              ; Set bed target (non-blocking)
    M104 S150                     ; Nozzle to standby — prevents charring
    M190 S{BED_TEMP}              ; Wait for bed to reach target
    M109 S{EXTRUDER_TEMP}         ; Now heat nozzle to full print temp

    # Load saved bed mesh
    BED_MESH_PROFILE LOAD=default

    # Short purge line on left edge
    G1 X2 Y20 Z0.3 F9000
    G1 X2 Y180 E12 F1200
    G1 E-0.5 F3000                ; Retract after purge
    G1 X5 F9000                   ; Wipe nozzle sideways

    G92 E0                        ; Reset extruder position

---
In OrcaSlicer → Machine Settings → Start G-code, paste:
START_PRINT BED_TEMP={bed_temperature} EXTRUDER_TEMP={temperature[0]}

/* Parametric Wall Spool Holder
   All key dimensions are Customizer variables */

/* [Wall Plate] */
plate_width = 60;          // mm
plate_height = 80;         // mm
screw_spacing = 40;        // mm, centre-to-centre
screw_dia = 4.5;           // M4 clearance

/* [Arm] */
arm_depth = 80;            // how far arm extends from wall
rod_dia = 20;              // spool axle hole diameter

/* [General] */
wall = 5;                  // wall thickness throughout
fillet_r = 6;              // inner corner fillet radius
$fn = 48;

module holder() {
    difference() {
        union() {
            // Wall plate
            cube([plate_width, wall, plate_height]);

            // Arm
            translate([0, 0, 0])
                cube([plate_width, arm_depth, wall]);

            // Fillet cylinder at inner corner
            translate([0, wall, wall])
                rotate([0, 90, 0])
                    cylinder(r=fillet_r, h=plate_width);
        }

        // Screw holes in wall plate (vertical)
        for (z = [plate_height/2 - screw_spacing/2,
                  plate_height/2 + screw_spacing/2]) {
            translate([plate_width/2, -1, z])
                rotate([-90,0,0])
                    cylinder(d=screw_dia, h=wall+2);
        }

        // Rod hole at arm tip
        translate([plate_width/2, arm_depth - wall/2, -1])
            cylinder(d=rod_dia, h=wall+2);
    }
}

holder();

Outer wall speed applies to all outer perimeters.
Small perimeter speed is a subset — it kicks in only for perimeters
below a radius threshold (default ~6mm diameter loops).

Why it matters:
At high speeds, tight curves cause visible quality loss — the printer's
motion system overshoots corners on small arcs, creating bumps on screw
bosses, round holes, and small cylindrical features.

Recommended ratio:
- General / decorative prints: 40-50% of outer wall speed
- Functional parts with tight tolerances: 25-30%
- Example: 150mm/s outer wall → 40-60mm/s small perimeters

The threshold (what counts as "small") is adjustable in OrcaSlicer
under Quality → Small perimeter threshold. Default 6mm is reasonable
for most 0.4mm nozzle printing.

For a 60-degree overhang with a 30mm bridge, you want tree (organic)
supports rather than normal supports. Here is the specific setup:

Support type: Tree (auto) — Bambu Studio handles placement well
Top interface layers: 2-3 (critical for surface quality)
Interface spacing: 0.2mm (this gap is what makes removal clean)
Interface pattern: Rectilinear
Support/model Z distance: 0.15-0.2mm

For the 30mm bridge:
- Enable bridge flow ratio 0.85-0.90 (slightly underextrude bridges
  to reduce sag)
- Bridge speed: 25-30mm/s regardless of your print speed
- If the bridge still sags: add a single support only at the centre

The interface layer spacing (0.2mm) is the key variable — too tight
and supports weld to the part; too loose and surface quality degrades.
Start at 0.2mm and adjust by 0.05mm increments.

For outdoor, UV-exposed, high-temp parts, your ranking is:

1. ASA — best choice for this application
   UV stable by design. HDT around 95-100°C handles 45°C summer easily.
   Requires enclosure (K1 Max has one — good) and 240-260°C nozzle / 90-100°C bed.
   Minor warping risk on large flat parts — use a brim and keep the door closed.

2. PETG — acceptable but UV degrades it over 1-2 years outdoors
   Will yellow and become brittle after extended sun exposure.
   Fine if you are willing to reprint every couple of years.
   Easier to print than ASA if you are less experienced with it.

3. ABS — avoid
   Less UV stable than ASA, warps badly, fumes. No advantage over ASA.

For ASA specifically on K1 Max:
- Use the Creality or Polymaker ASA profile as a starting point
- Reduce print speed by 30% vs your PLA speeds for first layer
- 4+ perimeters, 35-40% infill for structural pot holders
- Print with door closed and top cover on to trap heat

Flow rate calibration measures whether your printer is extruding the
right amount of plastic. Here is the complete process:

Step 1 — Print a calibration cube
  In your slicer, create a 20x20x20mm cube. Set:
  - 1 perimeter only (no infill, no top/bottom layers)
  - 0.4mm line width (matching your nozzle)
  - Disable seam alignment (use random seam)

Step 2 — Measure the wall thickness
  Use digital calipers. Measure each of the 4 walls in multiple spots,
  5-10mm up from the bed. Average the readings.
  Ignore the seam side — it will always be slightly thicker.

Step 3 — Calculate correction
  Target wall thickness = your nozzle diameter = 0.4mm
  
  New flow % = (0.4 / measured average) × current flow %
  
  Example: If you measured 0.43mm and flow is currently 100%:
  New flow = (0.4 / 0.43) × 100 = 93%

Step 4 — Apply and re-test
  Enter the new flow % in your slicer profile.
  Reprint the cube and re-measure. Repeat until walls are 0.40mm ±0.01mm.

Typical range: 90-105% is normal. Outside this suggests an e-steps issue.

Pressure advance (PA) compensates for the lag between the extruder
motor pushing filament and that filament actually reaching the nozzle tip.
At corners and speed changes, without PA, you get blobs (too much pressure)
or gaps (not enough). The value tells Klipper how far ahead to start
adjusting extrusion for upcoming speed changes.

To find your value:
1. Run SET_VELOCITY_LIMIT SQUARE_CORNER_VELOCITY=1 ACCEL=500 in Mainsail
2. Run the PA test: TUNING_TOWER COMMAND=SET_PRESSURE_ADVANCE
   PARAMETER=ADVANCE START=0 FACTOR=.005
3. Print a tall narrow tower at moderate speed

Reading the result:
  Look at the corners of the tower from the bottom up.
  - Bottom (low PA): corners have blobs and excess plastic
  - Middle (correct PA): corners are sharp and clean
  - Top (too high PA): corners show gaps or slight pull-back
  
  Measure the height of the clean section from the bottom:
  PA value = height_mm × 0.005

Typical values by extruder type:
  Bowden (long): 0.4–0.8
  Direct drive: 0.04–0.15
  K1 Max with stock extruder: usually 0.02–0.06