Parametric Round Container (No Height Limit)

Threaded Capsule Box — Parametric Round Container (No Height Limit)

A fully parametric, screw-together round container split into two "cups" (base + lid) instead of a body-and-flat-cap design. Both halves have real usable interior volume, so you can print objects taller than your printer's build volume by splitting the height across two prints that screw together into one continuous, uniform-diameter capsule.

Why this design

Most printable round-box-with-lid models treat the lid as a thin flat cap with no interior space — so your maximum object height is limited by your printer's Z build volume. This model instead gives both halves a full interior chamber, joined by a threaded section, so:

No wasted internal space in either half
The useful internal diameter stays constant everywhere, including through the threaded joint — the extra material the thread needs is taken from the outer diameter (a barely-there step, well under a couple of millimeters typically), never from the inside
Base and lid share the same uniform outer diameter (no ledges/steps), so both parts print with zero supports
The lid auto-orients for printing: flat ceiling down on the bed, thread facing up (best adhesion, best print quality on the threads)

Quick start

Set D_int (useful inner diameter) and H_int (useful inner height, once assembled) to whatever you actually need to fit inside.
Set H_base to how tall you want the base piece to print — this is the only dimension actually limited by your printer's build volume. The lid's height is computed automatically to reach your target H_int.
Pick your nozzle size and material — nearly everything else (wall thickness, thread size, printing clearance) scales automatically from these two choices.
Generate the model and export/download your STLs.
Print a short calibration test first (temporarily lower H_int/H_base and regenerate) to confirm the thread spins freely before committing to the full-size print.

Parameters

Parts to render

Parameter	What it does
parts	both / base only / lid only — render one piece at a time
view_mode	print = parts laid out side by side, ready to print · assembled = visual preview only, joined together (do not print in this mode)

Nozzle

Parameter	What it does
nozzle	0.2 / 0.4 / 0.6 / 0.8 mm. Drives the auto-calculated wall thickness, thread pitch, tooth depth, and printing clearance below

Material

Parameter	What it does
material	PLA / PETG / ASA / ABS — sets a sensible default thread-clearance factor (PLA shrinks least/is most precise; PETG tends to string/gum up in the thread; ASA/ABS shrink more and warp more)
advanced_material_override	Tick to override the automatic factor with your own calibrated number
material_factor_manual	Used only when the checkbox above is ticked

Useful internal dimensions

Parameter	What it does
D_int	Useful internal diameter — the actual free space for your object, constant throughout the whole piece, thread included
H_int	Total useful internal height once base + lid are assembled
H_base	External printed height of the base piece — this is the one dimension bound by your printer's max build height

The lid's height and the piece's real outer diameter/total external height are computed automatically from the values above — no need to work them out yourself.

Thread — fine tuning

Parameter	What it does
thread_angle	Flank angle of the thread tooth (degrees). Lower = narrower tooth along the helix (less material/overhang) at the cost of less flank contact
thread_turns	Number of thread turns. More = stronger grip, but a longer "dead" section that isn't part of the useful diameter transition zone
tooth_factor	Radial tooth depth = nozzle x tooth_factor. Lower for less overhang while printing; below ~1.2 the thread gets fragile
thread_wall_factor	Wall thickness around the bore in the threaded zone = nozzle x thread_wall_factor. Lower to reclaim outer diameter; below ~2.5 risks a too-thin wall

Quality

Parameter	What it does
$fn	Circle resolution (facets per circle)
thread_fn	Thread resolution

Outer surface texture

Parameter	What it does
texture	none / vertical ribs / dots / bricks / embossed diamonds / decorative spiral — purely decorative, applied only to the smooth cylindrical section, never on the thread itself
texture_depth	How much the texture protrudes (mm)
texture_density	Repeats around the circumference (meaning shifts slightly by texture: rows/columns for most, number of wraps for the spiral)

Wall thicknesses — nozzle multipliers

Parameter	What it does
wall_factor	Wall thickness = nozzle x wall_factor
floor_factor	Base floor / lid ceiling thickness = nozzle x floor_factor

Recommended values

Balanced (robust + reasonable print time) — good starting point: thread_turns = 3, thread_angle = 30, tooth_factor = 1.6–1.8, thread_wall_factor = 3.5–4, wall_factor = 5–6, floor_factor = 6–8
Prioritizing minimal filament use, still solid: thread_turns = 3, tooth_factor = 1.5, thread_wall_factor = 3, wall_factor = 4.5, floor_factor = 5, texture = none

tooth_factor and thread_wall_factor have the biggest effect on material use, since they set the outer diameter (D_joint) of the entire piece, not just the joint area — these are the two most effective levers if you want to trim filament without sacrificing thread reliability.

Printing notes

Both parts print upright, no supports needed.
The lid auto-flips for printing: flat ceiling on the bed, thread facing up.
Always do a short calibration print first when trying a new material/nozzle combination — thread fit is the one thing worth checking before committing to a tall, long print.
If a screwed-together joint feels too tight or too loose, adjust material_factor_manual (with the override ticked) rather than re-slicing with different tolerances in your slicer.