G-code

Floor adhesion and initial rise probe — 2026-09-29 (sketch 2026.09.29 spiral floor probe, commit 998669c)

Ranges

The field corner is marked with a tail: on the front-left sample, a 5 mm extra segment protrudes from the edge where the floor transitions into the wall.

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle 255 °C, bed 70 °C (donor temperatures)
• The sample uses the actual Gridfinity foot profile, size 2 (nominally 41.5 mm, without tolerance), from 2026.09.29 gridfinity foot probe: R0.8 rounding, then a 45° chamfer over 0.8 mm → 1.8 mm vertical section → 45° chamfer over 2.15 mm
• Nine samples in a 3 × 3 grid, centres spaced 45 mm apart, field centred at X128 Y128
• Each sample is one continuous seamless spiral, printed at 20 mm/s throughout:
  1. Floor: from a 3 mm point to the edge (as in the foot), exactly 7 turns; cooling off. Each of the four sides has its own coil pitch and overlap (see ranges), so the final contour is a rectangle rather than a square: at a 1.0 mm line width, the distances from the centre to the edges are front 10.0 / right 8.6 / back 7.55 / left 6.5 mm.
  2. Wall: without stopping, the same spiral continues upward from the edge for another 5 turns along the actual foot profile (only the beginning of the rise, not the full 4.75 mm height); the side-to-side difference accumulated on the floor is preserved throughout the rise. Cooling is set to 100%.
• Corner rounding grows with the slowest side — the one with the least overlap
• The nozzle centreline is always offset inward from the true outer profile surface by half the line width
• Sample height ranges from 1.8 to 3.0 mm (6 turns at the row's layer height: 1 floor turn + 5 rising turns)
• Print time 4 min 36 s, filament 707 mm

Bamboo rods — 2026-09-27 (sketch 2026.09.27 bamboo probe, commit 4d188b1)

Ranges

The front-left corner is marked by a tail on the bed grid.

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 235 °C throughout the print, including the bed grid (M109 wait before the grid); bed at 70 °C
• Part cooling at 100%
• Field of 6 × 6 rods at 3.1 mm spacing, 15.5 × 15.5 mm between the outer rod axes, centred at X128 Y128; 6 joints per rod, no bridges; rod tops at Z 14.45 … 15.70 mm (calculated)
• Bed grid: 6 lines along X at Z 0.5, each beginning with a 0.2 mm³ drop extruded in place; 6 lines along Y at Z 0.7; 0.8 × 0.5 mm line with 1.2 overfill (0.48 mm³/mm), 10 mm/s; the front-left corner is marked with a tail extending 5 mm left from the front line
• Order: tier by tier — first joints of all 36 rods, then all second joints, and so on. Tier 1 follows a serpentine path from the front-left corner: along X left to right, the next line right to left, with lines proceeding front to back; each following tier traverses the same path in reverse, starting from the rod where the previous tier ended
• Each joint:
  1. Travel directly at 60 mm/s at the height of the joint just printed (before the first joint, 0.5 mm above the grid).
  2. Lower to the base.
  3. Extrude the Y-specific base drop in place at 6 mm³/s; omit it when set to 0.
  4. Thick section: rise by 2.5 mm minus the thin-section height, extruding 1.1 mm³ per millimetre of rise at 0.5 mm/s (calculated flow 0.55 mm³/s).
  5. Thin section: rise by its X-specific height, extruding 0.5 mm³ per millimetre of rise at 0.5 mm/s; omit it when set to 0.
  6. No pause at the top, no retraction, no lift.
• Joint height — thick + thin section = 2.5 mm; the base is not included
• Print time 18 min 51 s, filament 295 mm

Stem cube, straight travels — 2026-09-26 (sketch 2026.09.26 stem cube straight, commit 8395a88)

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 235 °C throughout the print, including the bed grid (M109 wait before the grid); bed at 70 °C
• Part cooling at 100%
• Cube of 3 × 3 × 2 cells measuring 3 × 3 × 3 mm each: 4 × 4 nodes at 3 mm spacing, 9 × 9 mm footprint, centred at X128 Y128; top of the final beam at Z 6.7 mm (calculated)
• Bed grid: 4 rows at Z 0.5, 4 columns at Z 0.7, 0.8 × 0.5 mm line with 1.2 overfill (0.48 mm³/mm), 20 mm/s; the front-left corner is marked with a tail extending 5 mm left from the front line
• 2 tiers at 3 mm each: 2.4 mm stem + 0.6 mm beam (4 passes at 0.2 mm increments). Stem tops by tier at Z 3.1 / 6.1
• 16 stems per tier, 32 total; serpentine traversal from the front-left corner: one row left to right, the next right to left, rows front to back
• Each stem:
  1. Lower to the top of the node with no gap.
  2. Unretract 0.8 mm and pause for 0.5 s.
  3. Rise 2.4 mm while extruding 0.5 mm³ per millimetre of rise at 0.5 mm/s (calculated flow 0.25 mm³/s).
  4. Pause for 1.5 s at the top.
  5. Retract 0.8 mm, lift 1 mm above the tops, and travel to the next stem at 60 mm/s.
• Beams over the stem tops on each tier, 4 passes at 0.2 mm increments, with the first at stem-top height:
  1. Layer 1, rows — back to front from the left edge: 0.07 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  2. Layer 1, columns — left to right from the front edge: 0.07 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  3. Layer 2, rows — front to back from the right edge: 0.14 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  4. Layer 2, columns — right to left from the back edge: 0.14 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
• Each beam line consists of two strands offset ±0.175 mm from the node axis (0.35 mm between strands), printed at 15 mm/s: outward along one strand, turn, then back along the other. Pads are extruded in place at 6 mm³/s
• Between beam lines: lift 0.5 mm, travel along the field edge at 60 mm/s, lower; no retraction
• Direct travels: except for the move from the start to the grid, each travel follows X or Y or includes a 0.175 mm offset on the second axis (at a field corner when switching beam passes and from the last beam of a tier to the first stem of the next tier)
• Print time 4 min 32 s, filament 62 mm

Stem cube, straight travels — 2026-09-26 (sketch 2026.09.26 stem cube straight, commit 8395a88)

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 235 °C throughout the print, including the bed grid (M109 wait before the grid); bed at 70 °C
• Part cooling at 100%
• Cube of 3 × 3 × 2 cells measuring 3 × 3 × 3 mm each: 4 × 4 nodes at 3 mm spacing, 9 × 9 mm footprint, centred at X128 Y128; top of the final beam at Z 6.7 mm (calculated)
• Bed grid: 4 rows at Z 0.5, 4 columns at Z 0.7, 0.8 × 0.5 mm line with 1.2 overfill (0.48 mm³/mm), 20 mm/s; the front-left corner is marked with a tail extending 5 mm left from the front line
• 2 tiers at 3 mm each: 2.4 mm stem + 0.6 mm beam (4 passes at 0.2 mm increments). Stem tops by tier at Z 3.1 / 6.1
• 16 stems per tier, 32 total; serpentine traversal from the front-left corner: one row left to right, the next right to left, rows front to back
• Each stem:
  1. Lower to the top of the node with no gap.
  2. Unretract 0.8 mm and pause for 0.5 s.
  3. Rise 2.4 mm while extruding 0.5 mm³ per millimetre of rise at 0.5 mm/s (calculated flow 0.25 mm³/s).
  4. Pause for 1.5 s at the top.
  5. Retract 0.8 mm, lift 1 mm above the tops, and travel to the next stem at 60 mm/s.
• Beams over the stem tops on each tier, 4 passes at 0.2 mm increments, with the first at stem-top height:
  1. Layer 1, rows — back to front from the left edge: 0.07 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  2. Layer 1, columns — left to right from the front edge: 0.07 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  3. Layer 2, rows — front to back from the right edge: 0.14 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
  4. Layer 2, columns — right to left from the back edge: 0.14 mm³/mm strand, with 0.2 mm³ pads at both ends of the first strand.
• Each beam line consists of two strands offset ±0.175 mm from the node axis (0.35 mm between strands), printed at 15 mm/s: outward along one strand, turn, then back along the other. Pads are extruded in place at 6 mm³/s
• Between beam lines: lift 0.5 mm, travel along the field edge at 60 mm/s, lower; no retraction
• Direct travels: except for the move from the start to the grid, each travel follows X or Y or includes a 0.175 mm offset on the second axis (at a field corner when switching beam passes and from the last beam of a tier to the first stem of the next tier)
• Print time 4 min 32 s, filament 62 mm

Stem cube — 2026-09-26 (sketch 2026.09.26 stem cube, commit 5f8c95e)

Ranges

• Bridge extrusion: from 0.48 to 0.07 mm³/mm. It stays constant within each tier and changes from tier to tier, bottom to top: 0.48 / 0.35 / 0.25 / 0.15 / 0.07 mm³/mm.

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 235 °C throughout the print, including the bed-level grid (M109 wait before the grid); bed at 70 °C
• Part cooling at 100%
• Cube of 5 × 5 × 5 cells: 6 × 6 nodes at 3 mm spacing, 15 × 15 mm footprint, centred at X128 Y128; top of the final grid at Z 18.2 mm (calculated)
• Bed grid: 6 rows at Z 0.5, 6 columns at Z 0.7, 0.8 × 0.5 mm line with 1.2 overfill (0.48 mm³/mm), 20 mm/s; the front-left corner is marked with a tail extending 5 mm left from the front line
• 5 tiers at 3.5 mm each: 0.3 mm gap + 3 mm stem + 0.2 mm column lift. Stem tops by tier at Z 4.0 / 7.5 / 11.0 / 14.5 / 18.0
• 36 stems per tier, 180 total; row-wise traversal — each row left to right, rows front to back
• Each stem:
  1. Lower to the node, stopping 0.3 mm above the top of the node (the grid column beneath it).
  2. Unretract 0.8 mm and extrude a 2 mm³ base in place at 6 mm³/s.
  3. Rise 3 mm while extruding 1.4 mm³ per millimetre of rise at 0.5 mm/s (calculated flow 0.7 mm³/s).
  4. Pause for 1.5 s at the top.
  5. Retract 0.8 mm, lift 1 mm above the tops, and travel to the next stem at 60 mm/s.
• Grid over the stem tops on each tier:
  1. Rows at stem-top height, 15 mm/s, using that tier's extrusion; add another 0.5 mm³ in place at every node at 6 mm³/s.
  2. Columns 0.2 mm above the rows, 15 mm/s, at the same extrusion, with no extra material at the nodes.
  3. Between lines: lift 0.5 mm, travel at 60 mm/s, lower; no retraction.
• Peak flow 7.2 mm³/s, calculated for bridges at 0.48 mm³/mm × 15 mm/s
• Print time 25 min 34 s, filament 636 mm

Stem probe with a base — 2026-09-26 (sketch 2026.09.26 stem probe base, commit 69c0b94)

• Printer: Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Material: Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 255 °C for the grid (donor temperature), then 235 / 245 / 255 / 265 °C for the four blocks; bed at 70 °C
• Part cooling: 100%
• Four blocks in a 2 × 2 arrangement, each block 48 × 60 mm, 16 mm gap, field centred at X128 Y128; 235 °C front left, 245 front right, 255 rear left, 265 rear right
• One shared grid for all blocks: rows at Z 0.5, columns at Z 0.7, 0.8 × 0.5 mm line with 1.2 overfill (0.48 mm³/mm), 20 mm/s; the front-left corner is marked by extending the front line 5 mm to the left
• Matrix: extrusion along X is 0.2 / 0.5 / 0.8 / 1.1 / 1.4 mm³ per mm of lift; lift speed along Y (front to back) is 0.25 / 0.5 / 1 / 2 / 4 / 8 mm/s
• Stem spacing: 12 mm; 30 stems per block, 120 total
• Each stem:
  1. Lower to Z 1.0, leaving a 0.3 mm gap above the grid node.
  2. Unretract, then extrude a 1 mm³ base in place at 6 mm³/s.
  3. Rise to Z 5.0: 4 mm with the column's extrusion rate and the row's speed.
  4. Pause for 1.5 s at the top.
• Travel moves: 0.8 mm retract, rise 1 mm above stem tops, travel at 60 mm/s, lower, then 0.8 mm unretract
• Order: print the entire grid at the donor temperature, then print blocks from coldest to hottest while waiting for each temperature with M109; stems within each block are printed in rows from left to right
• Peak flow: 11.2 mm³/s, calculated for the 1.4 mm³/mm × 8 mm/s cell; the generator reports no warnings
• Print time: 17 min 8 s; filament: 750 mm

Stem probe — 2026-09-25 (sketch 2026.09.25 stem probe, commit 8c2a9b4)

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm, donor _donor_3mf/L.gcode.3mf
• Temperatures: nozzle at 255 °C for the base grid (the donor temperature), then 235 / 245 / 255 / 265 °C by block; bed at 70 °C
• Part cooling fan: 100%
• Four blocks in a 2 × 2 arrangement, each 48 × 60 mm, with a 16 mm gap between blocks, centered at X128 Y128; 235 °C front left, 245 °C front right, 255 °C rear left, 265 °C rear right
• One base grid shared by all blocks: rows at Z 0.5, columns at Z 0.7, 0.8 × 0.5 mm line with a 1.2 over-extrusion factor (0.48 mm³/mm), 20 mm/s; the front-left corner is marked by a tail, with the front line extending 5 mm left beyond the field
• Parameter grid: along X, extrusion 0.2 / 0.5 / 0.8 / 1.1 / 1.4 mm³ per mm of upward travel; along Y (front to back), upward speed 0.25 / 0.5 / 1 / 2 / 4 / 8 mm/s
• Stem spacing 12 mm, 30 stems per block, 120 total
• Each stem:
  1. Descend to Z 0.7, directly to the base-grid node with no gap.
  2. Unretract 0.8 mm; there is no separate base.
  3. Rise to Z 5.7, a 5 mm move with the column’s extrusion rate and the row’s speed.
  4. Pause for 1.5 s at the top.
• Travel moves: retract 0.8 mm, lift 1 mm above the stem tips, travel at 60 mm/s, descend, unretract 0.8 mm
• Order: print the entire base grid at the donor temperature, then print the blocks from coldest to hottest while waiting for each target temperature (M109); within each block, print the stems in a snake pattern, with even rows left to right and odd rows right to left
• Peak flow 11.2 mm³/s, calculated for the 1.4 mm³/mm × 8 mm/s cell
• Print time: 19 min 15 s; filament: 740 mm

Generator — run.py.

Retraction test — 2026-09-25 (sketch 2026.09.25 retract probe, commit 3e6c6ca)

• Printer, filament, temperatures, and cooling are the same as above
• Field: a 10 × 10 grid of rods at 5 mm spacing (45 × 45 mm), centered on the bed
• Along X, left to right: retraction 0; 0.2; 0.4; …; 1.8 mm
• Along Y, front to back: pause at the top before retraction 0; 0.22; 0.44; …; 2.0 s
• Corner marker at (0, 0), front left: the bottom grid line extends 5 mm to the left beyond the field
• Grid: 0.8 × 0.5 mm lines with 20% over-extrusion (0.48 mm³/mm), 10 mm/s. Rows (along X) at Z 0.5 mm, columns (along Y) at Z 0.7 mm. Each line is printed separately; the nozzle lifts 0.5 mm between lines.
• Rod: rise 5 mm from the top of the grid (Z 0.7) while extruding 0.8 mm³/mm at 5 mm/s (4 mm³ per rod); pause according to its row; retract according to its column at 30 mm/s; lift 1 mm and travel to the next node at 60 mm/s; descend, then unretract by the same distance.
• Path: serpentine by rows
• Print time: 5 min 17 s (excluding start and end); filament: 347 mm

Four mesh walls — 2026-09-24 (sketch 2026.09.24 mesh walls, commit 8953858)

General:

• Printer, filament, temperatures, and cooling are the same as above
• Four 20 × 4 × 20 mm walls (length × thickness × height) at the corners of a 100 × 100 mm square: A (78, 78), B (178, 78), C (78, 178), D (178, 178)
• The walls are printed one at a time, each in full: A, B, C, D
• Base of each wall: two solid 0.2 mm layers, 0.45 mm lines along the wall, 20 mm/s
• The wall faces run at y = ±1.2 mm from the centerline
• Strand: 0.35 × 0.2 mm (0.07 mm³/mm), 15 mm/s
• Droplets are extruded in place at 6 mm³/s
• Travel between walls: 0.8 mm retraction, lift to 1 mm above everything already printed, travel at 100 mm/s, descend, unretract
• Print time: 8 min 42 s (excluding start and end); filament: 598 mm

A “Truss” (bottom left):

• Six nodes along the wall at 3.6 mm intervals (x = −9…9), alternating between the front and rear faces to form a zigzag in plan view
• A 3 mm³ droplet at each node; node positions stay the same in every row
• Rows alternate direction
• 1.2 mm row height, 16 rows total

B “Running bond” (bottom right):

• 2.5 mm³ droplets on both faces at 4 mm intervals
• In even rows, droplets sit at x = −8, −4, 0, 4, 8; in odd rows, at x = −9, −6, −2, 2, 6, 9
• Each row is a closed loop: front face, crosspiece, rear face, crosspiece
• 1.2 mm row height, 16 rows total

C “Rails and posts” (top left):

• Seven tiers, each 2.86 mm high
• A rail is a continuous line around the perimeter of a tier. The first rests on the base (0.45 × 0.2 mm, 20 mm/s); the others bridge across the tops of the posts (0.45 × 0.3 mm, 8 mm/s). Eight rails total.
• Posts: four on each face per tier; bases spaced 5 mm apart; tops shifted 2.5 mm along the wall
• Each post is printed upward at 0.12 mm³/mm and 4 mm/s, followed by a 0.6 s pause at the top
• Post lean alternates from tier to tier
• Travel between posts: 0.8 mm retraction, 0.5 mm lift

D “Braid with stitches” (top right):

• Five nodes on each face (x = −8…8, 4 mm spacing)
• Even rows: crisscrossed strand, two zigzags between the faces
• Odd rows: ladder pattern — front face, crosspiece, rear face, crosspiece
• A stitch at each node: strand down to 0.2 mm above the row below; 1 mm³ extruded in place; strand back up; 3 mm³ droplet
• 2 mm row height, 10 rows total

Shader lattice on a cylinder, 1 mm layer height — 2026-09-24 (sketch 2026.09.24 shader lattice layer 1mm, commit 0f940c0)

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm
• Temperatures: 255 °C nozzle, 70 °C bed
• Part cooling fan: 100%
• Relief cylinder: radius from 20 to 28 mm (8 mm outward relief), centered at X128 Y128
• Pattern: 10 periods around the circumference, 25.1 mm vertical period
• Base: a continuous line along the lower contour at Z 0.2 mm, 0.5 × 0.2 mm, 20 mm/s
• Layer height: 1 mm. First droplet layer at Z 0.7 mm (0.5 mm above the base), 50 layers total, final layer at Z 49.7 mm
• Droplet spacing along the contour: 4 mm. Each new droplet is placed midway between the droplets of the previous layer.
• Droplet: 2.5 mm³ on the surface, 4 mm³ on the ribs (where the contour runs radially); extruded in place at 6 mm³/s. 5140 droplets total, 5090 of them on the ribs.
• Strand between droplets: 0.35 × 0.2 mm (0.07 mm³/mm), 15 mm/s
• Travel across holes: 0.8 mm retraction, 0.6 mm lift, travel at 60 mm/s, descend, 0.8 mm unretraction. 719 travel moves total.
• Print time: 71 min 19 s (excluding start and end); filament: 8847 mm

Shader lattice on a cylinder — 2026-09-24 (sketch 2026.09.24 shader lattice, commit ae2bc4d)

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm
• Temperatures: 255 °C nozzle, 70 °C bed
• Part cooling fan: 100%
• Relief cylinder: radius from 20 to 28 mm (8 mm outward relief), centered at X128 Y128
• Pattern: 10 periods around the circumference, 25.1 mm vertical period
• Base: a continuous line along the lower contour at Z 0.2 mm, 0.5 × 0.2 mm, 20 mm/s
• Layer height: 2 mm; first droplet layer at Z 0.7 mm (0.5 mm above the base); 25 layers total; final layer at Z 48.7 mm
• Droplet spacing along the contour: 4 mm. Each new droplet is placed midway between the droplets of the previous layer.
• Droplet: 2.5 mm³ on the surface, 4 mm³ on the ribs where the contour runs radially. Extruded in place at 6 mm³/s. 2370 droplets total, 2360 of them on the ribs.
• Strand between droplets: 0.35 × 0.2 mm (0.07 mm³/mm), 15 mm/s
• Travel across holes: 0.8 mm retraction, 0.6 mm lift, travel at 60 mm/s, descend, 0.8 mm unretraction. 369 travel moves total.
• Print time: 33 min 31 s; filament: 4107 mm

Droplet spiral stitch — 2026-09-23 (sketch 2026.09.23 drip spiral stitch, commit 67fa49a)

Ranges

• Droplet volume: 4 to 8 mm³. It follows a sawtooth over every revolution: the first droplet (0°) is 4 mm³ and the last one (345.6°) is 8 mm³, increasing by 1/6 mm³ ≈ 0.167 mm³ per droplet. Formula: V(i) = 4 + 4·i/24, i = 0…24.
• Pitch: 2 to 5 mm. It stays constant within each revolution and increases stepwise by 0.1875 mm on every new revolution. Formula: h(n) = 2 + 3·(n−1)/16, n = 1…17. Values by turn, mm: 1 — 2.00 · 2 — 2.19 · 3 — 2.38 · 4 — 2.56 · 5 — 2.75 · 6 — 2.94 · 7 — 3.13 · 8 — 3.31 · 9 — 3.50 · 10 — 3.69 · 11 — 3.88 · 12 — 4.06 · 13 — 4.25 · 14 — 4.44 · 15 — 4.63 · 16 — 4.81 · 17 — 5.00.

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm
• Temperatures: 255 °C nozzle, 70 °C bed
• Part cooling fan: 100%
• Cylinder Ø40 mm, centered at X128 Y128
• Base: 3 spiral turns at Z 0.2 mm (radii 18.65…20 mm), 0.5 × 0.2 mm line, 20 mm/s
• 25 droplets per revolution, 14.4° step, 5.03 mm arc distance between droplets
• Flat turns: every droplet of a revolution is at the same height; the lift to the next turn happens at the end of the revolution
• Each droplet:
  1. A 0.35 × 0.2 mm strand (0.07 mm³/mm) at 15 mm/s to the next droplet, at turn height.
  2. Descend with the same strand at 15 mm/s to the top of the droplet on the previous turn + 0.2 mm.
  3. Extrude 1 mm³ in place (6 mm³/s).
  4. Rise with the same strand at 15 mm/s back to turn height along the same vertical line.
  5. Extrude droplet V(i) in place at 6 mm³/s (4 mm³ in 0.67 s, 8 mm³ in 1.33 s).
• 17 turns, total height 59.7 mm
• Print time: 14 min 7 s; filament: 1396 mm

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm
• Temperatures: 255 °C nozzle, 70 °C bed
• Part cooling fan: 100%
• Cylinder Ø40 mm, centered at X128 Y128
• Base: 3 spiral turns at Z 0.2 mm (radii 18.65…20 mm), 0.5 × 0.2 mm line, 20 mm/s
• 25 droplets per revolution, 14.4° step, 5.03 mm arc distance between droplets
• Flat turns: all droplets of a revolution at one height, the lift to the next turn happens at the end of the revolution
• Pitch increases stepwise on every revolution: from 1.5 mm (turn 1) to 3.0 mm (turn 27), h(n) = 1.5 + 1.5·(n−1)/26
• Droplet volume follows a sawtooth over every revolution, from 4 to 8 mm³: V(i) = 4 + 4·i/24, i = 0…24
• Each droplet:
  1. 0.35 × 0.2 mm strand at 15 mm/s to the next droplet, at turn height;
  2. travel down without extrusion at 10 mm/s to the top of the droplet on the previous turn + 0.2 mm;
  3. 1 mm³ extruded in place (6 mm³/s);
  4. rise back to turn height while extruding V(i) at 6 mm³/s (≈1–3 mm/s);
  5. 1 s pause.
• Full file: 27 turns, 61.0 mm tall, 30 min 49 s, 2078 mm of filament; the first 3 turns were printed

Observations

• Dipping the nozzle to the previous turn did not produce knots: at 1.5–1.62 mm pitch and 5–9 mm³ droplets, every droplet is smooth.
• The weak spot is where the strand leaves the droplet. A possible cause: during the 1 s pause under full cooling the top of the droplet cools down, so the thin strand (0.07 mm³/mm) barely fuses to it and gets stretched instead.

Pitch is how far each turn sits above the previous one, i.e. the height from which a droplet is extruded onto the turn below.

Print parameters

• Bambu Lab P1S, 0.4 mm nozzle, Textured PEI Plate
• Syntech PETG White, Ø1.75 mm
• Temperatures: 255 °C nozzle, 70 °C bed
• Part cooling fan: 100%
• Cylinder Ø40 mm, centered at X128 Y128
• Base: 3 spiral turns at Z 0.2 mm (radii 18.65…20 mm), 0.5 × 0.2 mm line, 20 mm/s
• First wall turn at Z 0.7 mm, or 0.5 mm above the base
• 25 droplets per revolution, 14.4° step, 5.03 mm arc distance between droplets
• Connecting strand: 0.35 × 0.2 mm, 15 mm/s
• Pitch remains constant within each revolution and increases stepwise on every new revolution: from 1.0 mm (turn 1) to 3.0 mm (turn 30), h(n) = 1 + 2·(n−1)/29
• Droplet volume follows a sawtooth over every revolution, growing from 1 to 4 mm³: V(i) = 1 + 3·i/24, i = 0…24
• Each droplet is extruded in place at 6 mm³/s: 1 mm³ in 0.17 s, 4 mm³ in 0.67 s
• 30 revolutions, total height 60.7 mm
• Print time: 9 min 44 s; filament: 904 mm

Observations

• The larger the droplet, the higher the wall remains intact and the later smooth droplets turn into knots.
• In every sector, the wall breaks within 0–5 revolutions after the knots begin to appear.

Geometry

• Cylinder radius: 5 mm (10 mm diameter)
• Total print height: 60.2 mm (0.2 mm base + 60 mm droplet wall)
• Angular step between droplets: 10°, or 36 droplets per revolution
• Horizontal arc distance between adjacent droplets at a 5 mm radius: 0.873 mm

Spiral pitch

Vertical rise per revolution:

• from 1 mm at the bottom to 10 mm at the top
• one smooth linear transition over the full height

Droplet volume

• From 0.01 mm³ to 5 mm³
• Angular sawtooth: linear growth over the full revolution (0→360°), followed by an abrupt reset to the minimum at the start of the next revolution
• Each droplet is extruded in place without nozzle movement: the nozzle travels to the point and extrudes while stationary

Droplet extrusion speed

• Constant: 50% of the donor filament profile's maximum volumetric flow. For PETG on the P1S this is 12 mm³/s, so the experiment uses 6 mm³/s regardless of droplet size
• Converted to filament feed for 1.75 mm filament: 2.5 mm/s; in G-code this is F150

Connecting strand

It holds the droplets together around the circumference; without it, the structure cannot stand.

• Width: 0.35 mm
• Cross-section height: 0.2 mm
• Volume per millimeter of travel: 0.07 mm³/mm
• Travel speed: 15 mm/s
• Independent of spiral pitch, so its thickness remains constant

Base

• Solid disk for bed adhesion
• Spiral from center to edge, with a 0.5 mm line width and 0.2 mm height
• The number of turns is chosen for approximately 10% overlap, leaving no gaps

Donor: L-profile by Justagwas
Material: PETG
Printer: Bambu Lab P1S
Nozzle: 0.4 mm