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Featured Model of the Day

Pipe elbow STL 3D file 87° ⌀OD: 40 mm ⌀ID: 32 mm thickness: 4 mm 📦 #2504

1 object(s) - format STL

gizmo

Latest user-generated 3D models

Tube STL 3D file OD 25.7 mm, ID 21.9 mm, length 152 mm 📦 #11063

1 object(s) - format STL

gizmo

From the Blog

Why Modeling Strategy Matters in Procedural CAD Modeling

2025-12-14 · 3D Modeling · sylvain
why Modeling Strategy Matters in Procedural CAD Modeling why Modeling Strategy Matters in Procedural CAD Modeling

Why does modeling strategy matter so much in procedural CAD? Two scripts can produce the exact same geometry while showing very different generation times.

Using a concrete build123d example, this article explains why certain operations, such as fillets, become expensive when repeated at scale, and how a simple change in approach can drastically reduce computation time.

A clear overview of the key challenges in procedural modeling, highlighting the direct impact of design choices on CAD engine performance.

Read the article

A selection of custom 3D models

📦 Model #1483

1 object(s)
- format STL
Tube adapter STL file ⌀ 200–50 mm (Length: 80 mm)
Tube adapter STL file ⌀ 200–50 mm (Length: 80 mm)
Tube reducer ⌀200 mm to ⌀50 mm in STL 3D format. Total length of this junction is 80 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 30 mm, the smaller one of 30 mm as well. The ends have no fillet.
Parameter Value Unit
side A length 30 mm
side A outer diameter 200 mm
side A thickness 3 mm
side B length 30 mm
side B outer diameter 50 mm
side B thickness 3 mm
transition length 20 mm
axis offset 0 mm
ends fillet no fillet

📦 Model #3461

2 object(s)
- format STL
Honeycomb grille STL 3D file, center-to-center: 30x30mm, mesh: 3mm - Ø4mm
Honeycomb grille STL 3D file, center-to-center: 30x30mm, mesh: 3mm - Ø4mm
View of object #0
Download this square honeycomb grid as a STL file. Mounting holes are placed at the four corners (center-to-center 30x30 mm), each with a diameter of Ø4 mm. The overall dimensions reach 38x38 mm, with fine 3 mm cell size for maximum protection. A secondary color rim highlights the outer edge. This grid acts as a protective guard while allowing airflow.
Parameter Value Unit
length or center-to-center 30 mm
width or center-to-center 30 mm
mesh size 3 mm
dual color yes
holes yes
hole diameter 4 mm

📦 Model #4258

1 object(s)
- format STL
Pipe elbow STL file 90° ⌀OD: 26.3 mm ⌀ID: 22 mm thickness: 2.15 mm
Pipe elbow STL file 90° ⌀OD: 26.3 mm ⌀ID: 22 mm thickness: 2.15 mm
3D model of an elbow with a 90° angle in STL format. This elbow features an external diameter of 26.3 mm and an internal diameter of 22 mm. The tube thickness is therefore 2.15 mm.
Parameter Value Unit
outer diameter 26.3 mm
inner diameter 22 mm
angle 90 °
end fillets no

📦 Model #3612

1 object(s)
- format STL
Protective grid STL 3D file, center-to-center: 210x110mm, mesh: 10mm - Ø5mm
Protective grid STL 3D file, center-to-center: 210x110mm, mesh: 10mm - Ø5mm
Download this rectangular protective honeycomb grid model in STL format. Mounting holes are placed at the four corners (center-to-center 210x110 mm), each with a diameter of Ø5 mm. The overall dimensions reach 220x120 mm, with very large 10 mm cell size for peak ventilation. This grid serves as both a protective guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 210 mm
width or center-to-center 110 mm
mesh size 10 mm
dual color no
holes yes
hole diameter 5 mm

📦 Model #1084

1 object(s)
- format STL
Multi-compartment box STL 3D file: 200 compartments of 2×2×2 mm
Multi-compartment box STL 3D file: 200 compartments of 2×2×2 mm
This parametric compartment box provides 200 compartments measuring 2×2×2mm each. Overall dimensions are 42×82×4mm.
Parameter Value Unit
number of rows 20
number of columns 10
compartment length 2 mm
compartment width 2 mm
compartment height 2 mm
wall thickness 2 mm
compartment fillet (radius) 0.8 mm

📦 Model #6362

2 object(s)
- format STL
Rectangular-base box with lid STL 3D model – 84×45×20 mm, wall thickness 2 mm
Rectangular-base box with lid STL 3D model – 84×45×20 mm, wall thickness 2 mm
View of object #0
Rectangular-base box with a lid provided as a STL 3D file. Overall dimensions are 84 mm long, 45 mm wide, and 20 mm tall. The box features thin 2 mm walls. Interior and exterior edges are rounded. A small clearance is included to ensure a precise fit between the box and the lid. The internal dimensions, excluding rounding, are 80 mm × 41 mm × 16 mm.
Parameter Value Unit
length 84 mm
width 45 mm
height 20 mm
wall thikness 2 mm

📦 Model #2414

2 object(s)
- format STL
Small parts organizer with 4 drawers 110×90×110 mm STL 3D file, thickness: 2 mm
Small parts organizer with 4 drawers 110×90×110 mm STL 3D file, thickness: 2 mm
View of object #0
File of a multi-drawer box in 3D STL format. This model contains 4 compartments, arranged in 2 rows and 2 columns. Practically speaking, this means 2 rows of 2 compartments. Each compartment has usable dimensions of 110 mm wide, 90 mm high, and 110 mm deep. The wall thickness is 2 mm. The global dimensions of the box come to 235 x 191 x 116 mm. All the objects in this model were designed to be printed without support generation.
Parameter Value Unit
number of rows 2
number of columns 2
inner drawer depth 110 mm
inner drawer width 110 mm
inner drawer height 90 mm
wall thickness 2 mm
removable divider none

📦 Model #3475

1 object(s)
- format STL
L-bracket 200×150 mm STL 3D file, thickness 8 mm, hole diameter 5 mm
L-bracket 200×150 mm STL 3D file, thickness 8 mm, hole diameter 5 mm
Download this file of a right-angle bracket reinforced in STL 3D format. The dimensions are 200 mm in length, 150 mm in height, 15 mm in width, and 8 mm in thickness. The holes are designed with a diameter of 5 mm. Chamfers are done to the holes to seat the screw heads. The central reinforcement bar enhances mechanical strength and includes two passages for fastening. No support is needed to print this bracket, placed flat directly on the build plate.
Parameter Value Unit
length 200 mm
height 150 mm
width 15 mm
thickness 8 mm
hole diameter 5 mm
chamfer on the holes yes

📦 Model #4476

1 object(s)
- format STL
Tubing adapter STL 3D file ⌀ 40–37 mm (Length: 115 mm)
Tubing adapter STL 3D file ⌀ 40–37 mm (Length: 115 mm)
Tube adapter ⌀40 mm to ⌀37 mm in STL 3D format. Length of this connector is 115 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 40 mm. The ends are rounded to facilitate the connection of the two tubes.
Parameter Value Unit
side A length 35 mm
side A outer diameter 40 mm
side A thickness 5 mm
side B length 40 mm
side B outer diameter 37 mm
side B thickness 5 mm
transition length 40 mm
axis offset 0 mm
ends fillet fillet on bo...

📦 Model #1396

1 object(s)
- format STL
Round air vent STL file ∅ 71.2 mm, slat angle: 45° with central reinforcement
Round air vent STL file ∅ 71.2 mm, slat angle: 45° with central reinforcement
3D design of a round grille for air circulation in STL format. Its male diameter measures 71.2 mm. The slats have an angle of 45° and a low thickness of 1.6 mm. A central reinforcement reinforces the slats. This vent cover has a thin flange of 5 mm. The total diameter of this model is 81.2 mm.
Parameter Value Unit
male diameter 71.2 mm
slat angle 45 °
slat thickness 1.6 mm
flange width 5 mm
central reinforcement yes

📦 Model #2390

1 object(s)
- format STL
Round air vent STL 3D file ∅ 115 mm, slat angle: 45°
Round air vent STL 3D file ∅ 115 mm, slat angle: 45°
3D file of a round grille for air circulation in STL format. Its male diameter is 115 mm. The slats have an angle of 45° and a high thickness of 2 mm. This ventilation grille has a collar of 10 mm. The full diameter of this model is 135 mm.
Parameter Value Unit
male diameter 115 mm
slat angle 45 °
slat thickness 2 mm
flange width 10 mm
central reinforcement no

📦 Model #1158

2 object(s)
- format STL
Enclosure with screw-mounted lid STL 3D file: 110×70×35 mm
Enclosure with screw-mounted lid STL 3D file: 110×70×35 mm
View of object #0
Download this enclosure with a screwed lid in STL format. The dimensions are 110 mm long by 70 mm wide and 35 mm high. The lid measures 20 mm high. Wall thickness is 4 mm. The enclosure does not have cooling.
Parameter Value Unit
length 110 mm
width 70 mm
total height 35 mm
lid height 20 mm
wall thickness 4 mm
screw margin 0 mm
fit clearance 0.1 mm
cooling zone(s) no cutouts

📦 Model #1363

1 object(s)
- format STL
Pipe elbow STL 3D file 30° ⌀OD: 50 mm ⌀ID: 46 mm thickness: 2 mm
Pipe elbow STL 3D file 30° ⌀OD: 50 mm ⌀ID: 46 mm thickness: 2 mm
Model of an elbow with a 30° angle in STL format. This pipe elbow has an outer diameter of 50 mm and an inner diameter of 46 mm. The tube thickness is therefore 2 mm.
Parameter Value Unit
outer diameter 50 mm
inner diameter 46 mm
angle 30 °
end fillets no

📦 Model #4414

2 object(s)
- format STL
Round box with lid STL 3D file ⌀ 134 mm - Height: 20 mm, Shell: 2 mm
Round box with lid STL 3D file ⌀ 134 mm - Height: 20 mm, Shell: 2 mm
View of object #0
Get this circular box model in 3D STL format. Its diameter is 134 mm and its total height is 20 mm. The wall thickness is 2 mm. A fillet located at the bottom of the box makes it easier to grip objects.
Parameter Value Unit
external diameter 134 mm
total height 20 mm
wall thickness 2 mm
fit clearance 0.2 mm
inner bottom fillet 1 mm

📦 Model #3981

1 object(s)
- format STL
Rectangular tube adapter STL file 220x90 mm to 180x95 mm – transition: 140 mm
Rectangular tube adapter STL file 220x90 mm to 180x95 mm – transition: 140 mm
Rectangular duct connector downloadable as STL 3D file. The internal cross-section on side A is 220x90 mm (rectangular), while side B is 180x95 mm (rectangular). Each sleeve provides an insertion length of 40 mm. The transition section runs for 140 mm and the overall length is 220 mm, sleeves included. External chamfers are added at the ends to make it easier to push the adapter into ducts or pipes. An offset of 70 mm along the Y axis is applied to side B with respect to side A.
Parameter Value Unit
side A internal width 220 mm
side A internal height 90 mm
sleeve length on side A 40 mm
side B internal width 180 mm
side B internal height 95 mm
sleeve length on side B 40 mm
thickness 3 mm
transition length 140 mm
Y offset 70 mm
Z offset 0 mm
end chamfers outside

📦 Model #4145

1 object(s)
- format STL
Honeycomb grille STL file, 195x80mm, mesh: 7mm
Honeycomb grille STL file, 195x80mm, mesh: 7mm
Download this rectangular protective grid file in STL format. The overall size is 195x80 mm, with wide 7 mm cell size to enhance ventilation. This grid acts as a protective guard while allowing airflow.
Parameter Value Unit
length or center-to-center 195 mm
width or center-to-center 80 mm
mesh size 7 mm
dual color no
holes no

📦 Model #3502

1 object(s)
- format STL
Protective grid STL 3D file, 60x60mm, mesh: 8mm
Protective grid STL 3D file, 60x60mm, mesh: 8mm
Download this 3D square honeycomb grid model in STL format. The overall size is 60x60 mm, with wide 8 mm cell size for optimal air circulation. This type of grid serves both protection and ventilation roles.
Parameter Value Unit
length or center-to-center 60 mm
width or center-to-center 60 mm
mesh size 8 mm
dual color no
holes no

📦 Model #768

1 object(s)
- format STL
Rectangular prism STL 3D file 100×42×57 mm
Rectangular prism STL 3D file 100×42×57 mm
A 3D STL file of a box. Its overall dimensions are 100×42×57 mm. This model has no fillet on the sides.
Parameter Value Unit
length 100 mm
width 42 mm
height 57 mm
fillet radius 0 mm

📦 Model #4309

1 object(s)
- format STL
Multi-compartment box STL file: 100 compartments of 50×50×50 mm
Multi-compartment box STL file: 100 compartments of 50×50×50 mm
This parametric sectioned box features 100 storage spaces measuring 50×50×50mm each. Overall dimensions are 555×555×55mm. A 20mm fillet applied to each compartment provide a better grip stored in slots. The dividers are particularly robust.
Parameter Value Unit
number of rows 10
number of columns 10
compartment length 50 mm
compartment width 50 mm
compartment height 50 mm
wall thickness 5 mm
compartment fillet (radius) 20 mm

📦 Model #2892

1 object(s)
- format STL
Shelf bracket 250×100 mm STL file, thickness 8 mm, hole diameter 6 mm
Shelf bracket 250×100 mm STL file, thickness 8 mm, hole diameter 6 mm
Model of a right-angle bracket reinforced in STL format. The dimensions are 250 mm in length, 100 mm in height, 50 mm in width, and 8 mm in thickness. The screw holes have a diameter of 6 mm. Chamfers are done to the holes for a cleaner fit of the screws. The central reinforcement bar reduces bending and includes two clearances for fastening. No support is needed to print this bracket, lying flat directly on the build plate.
Parameter Value Unit
length 250 mm
height 100 mm
width 50 mm
thickness 8 mm
hole diameter 6 mm
chamfer on the holes yes

📦 Model #3491

1 object(s)
- format STL
Protective grid STL file, center-to-center: 107x107mm, mesh: 10mm - Ø5mm
Protective grid STL file, center-to-center: 107x107mm, mesh: 10mm - Ø5mm
3D square protective honeycomb grid model as a STL file. Mounting holes are placed at the four corners (center-to-center 107x107 mm), each with a diameter of Ø5 mm. The overall dimensions reach 117x117 mm, with very large 10 mm cell size for maximum airflow. This grid serves as both a protective guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 107 mm
width or center-to-center 107 mm
mesh size 10 mm
dual color no
holes yes
hole diameter 5 mm

📦 Model #1696

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL 3D file ⌀99.5 mm to 170×100 mm, thickness 2 mm
Round-to-Rectangular Tube Adapter STL 3D file ⌀99.5 mm to 170×100 mm, thickness 2 mm
Download this file in STL format of a round-to-rectangular tube adapter with an outer diameter of ⌀99.5 mm and a rectangular section with inner dimensions 170×100 mm. The wall thickness is 2 mm and the overall length is 120 mm. Chamfers are applied on the outside of the cylindrical end and on the inside of the rectangular end to ease insertion.
Parameter Value Unit
cylinder outer diameter 99.5 mm
cylinder inlet length 30 mm
rectangle internal length 170 mm
rectangle internal height 100 mm
rectangle inlet length 30 mm
offset Z 0 mm
offset Y 0 mm
total length 120 mm
thickness 2 mm
chamfer chamfers on ...

📦 Model #2293

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL file ⌀100 mm to 196×86 mm, thickness 2 mm + offset
Round-to-Rectangular Tube Adapter STL file ⌀100 mm to 196×86 mm, thickness 2 mm + offset
Download this file in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀100 mm and a rectangular section with internal dimensions 196×86 mm. The shell thickness is 2 mm and the total length is 200 mm. The adapter has an offset of 53 mm along the Z axis.
Parameter Value Unit
cylinder outer diameter 100 mm
cylinder inlet length 40 mm
rectangle internal length 196 mm
rectangle internal height 86 mm
rectangle inlet length 53 mm
offset Z 53 mm
offset Y 0 mm
total length 200 mm
thickness 2 mm
chamfer no chamfer

📦 Model #984

1 object(s)
- format STL
U-shaped handle STL file 50×140×14 mm (Center-to-center 126 mm)
U-shaped handle STL file 50×140×14 mm (Center-to-center 126 mm)
Download this STL 3D model of a simple U-shaped furniture handle. The overall dimensions are 50×140×14 mm. The handle features a square profile combined with a smooth transition. The bores are 6 mm diameter and have a 126 mm center-to-center distance.
Parameter Value Unit
width 50 mm
length 140 mm
thickness 14 mm
shape (0:square,1:circle) 0
transition (0:right,1:rounded) 1
fillet radius 0 mm
hole diameter 6 mm

📦 Model #4201

1 object(s)
- format STL
Washer / Flat Gasket STL 3D file ⌀ID: 3.9 mm ⌀OD: 6.9 mm thickness: 4.3 mm
Washer / Flat Gasket STL 3D file ⌀ID: 3.9 mm ⌀OD: 6.9 mm thickness: 4.3 mm
3D model of washer / gasket in STL 3D file format. This part features an inner diameter of ⌀3.9 mm and an outer diameter of ⌀6.9 mm. The total thickness is 4.3 mm. This part has no finish applied.
Parameter Value Unit
inner diameter 3.9 mm
outer diameter 6.9 mm
thickness 4.3 mm
finish none

📦 Model #4396

1 object(s)
- format STL
Honeycomb grid STL file, 250x250mm, mesh: 10mm
Honeycomb grid STL file, 250x250mm, mesh: 10mm
Square grid model as a STL file. The overall size is 250x250 mm, with very large 10 mm cell size for maximum airflow. This grid serves as both a protective guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 250 mm
width or center-to-center 250 mm
mesh size 10 mm
dual color no
holes no

📦 Model #4503

1 object(s)
- format STL
Tube adapter STL 3D file ⌀ 125–80 mm (Length: 105 mm)
Tube adapter STL 3D file ⌀ 125–80 mm (Length: 105 mm)
Straight tube coupler ⌀125 mm to ⌀80 mm in STL format. Total length of this junction is 105 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 40 mm. The ends are raw.
Parameter Value Unit
side A length 35 mm
side A outer diameter 125 mm
side A thickness 5 mm
side B length 40 mm
side B outer diameter 80 mm
side B thickness 5 mm
transition length 30 mm
axis offset 0 mm
ends fillet no fillet

📦 Model #3057

1 object(s)
- format STL
Right-angle bracket 150×150 mm STL 3D file, thickness 6 mm, hole diameter 6 mm
Right-angle bracket 150×150 mm STL 3D file, thickness 6 mm, hole diameter 6 mm
3D file of a mounting bracket with a central reinforcement in STL format. The dimensions are 150 mm in length, 150 mm in height, 14 mm in width, and 6 mm in thickness. The screw holes are designed with a diameter of 6 mm. Chamfers are applied to the holes to improve the seating of the heads. The central reinforcement bar reduces bending and provides two clearances for screwdriver access. No support is needed to print this bracket, printed flat on the build plate.
Parameter Value Unit
length 150 mm
height 150 mm
width 14 mm
thickness 6 mm
hole diameter 6 mm
chamfer on the holes yes

📦 Model #4475

1 object(s)
- format STL
Tube adapter STL 3D file ⌀ 40–37 mm (Length: 118 mm)
Tube adapter STL 3D file ⌀ 40–37 mm (Length: 118 mm)
Straight tube fitting ⌀40 mm to ⌀37 mm in STL format. Total length of this connector is 118 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 38 mm, the smaller one of 40 mm. The ends have a fillet to make tube connection easier.
Parameter Value Unit
side A length 38 mm
side A outer diameter 40 mm
side A thickness 5 mm
side B length 40 mm
side B outer diameter 37 mm
side B thickness 5 mm
transition length 40 mm
axis offset 0 mm
ends fillet fillet on bo...

📦 Model #4497

1 object(s)
- format STL
Tubing adapter STL 3D file ⌀ 32–19 mm (Length: 65 mm)
Tubing adapter STL 3D file ⌀ 32–19 mm (Length: 65 mm)
Tube fitting ⌀32 mm to ⌀19 mm in STL 3D format. Length of this junction is 65 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 20 mm. The ends are not rounded.
Parameter Value Unit
side A length 35 mm
side A outer diameter 32 mm
side A thickness 2 mm
side B length 20 mm
side B outer diameter 19 mm
side B thickness 2 mm
transition length 10 mm
axis offset 0 mm
ends fillet no fillet

STL: Advantages and Disadvantages for 3D Printing

The STL format is, without question, a cornerstone of 3D printing. This exchange format has established itself as the universal standard for representing 3D models ever since the early days of stereolithography. Its main strength lies in its simplicity: it describes the surface of an object using countless small triangles that form a mesh. This approach, known as tessellation, makes STL 3D files universally compatible with nearly all CAD software and slicers. If you’d like to learn more about this format, check out our article STL: What Is This 3D File Format?.

One of the major advantages of the format lies in this universality: whether you’re using a complex modeling program or a simpler design tool, you can export your 3D models in STL 3D format with near certainty that they’ll be interpreted correctly by your 3D printer. This ease of exchange has played a key role in the widespread adoption of 3D printing, allowing anyone to share and print objects without worrying about software compatibility. Once again, simplicity is its greatest strength.

However, that same simplicity also brings certain limitations. The triangle mesh, while effective for describing geometry, contains no information about colors, textures, or materials. For more advanced projects requiring these details, the STL format starts to show its weaknesses. Additionally, print quality depends directly on the fineness of the tessellation: too few triangles can lead to rough or faceted surfaces, while an overly dense mesh can make the file unnecessarily heavy.

Another notable drawback is the lack of unit management. An STL file doesn’t specify whether dimensions are in millimeters, centimeters, or inches, which can sometimes cause scaling errors when importing into a slicer. Despite these limitations, the STL format remains the go-to standard for converting your 3D models into G-code — the language your printer understands. It continues to be the preferred choice for its robustness and broad compatibility, even as newer formats like 3MF emerge for more specialized needs.

What is parametric modeling?

Parametric modeling is a fundamental approach in computer-aided design (CAD) that reshapes how 3D models are created and managed. Far from being a simple drawing technique, it represents a genuine design philosophy where objects are defined not by fixed shapes, but by variables and intelligent relationships.

This method makes it possible to modify the length, width, or diameter of a part and have the entire design adapt automatically, without the need to redraw everything. At the core of the process are parameters—numerical values (length, angle, thickness, etc.)—linked together through constraints and formulas. For instance, the diameter of a hole can be defined as half the width of a plate; if the width changes, the hole’s diameter instantly adjusts, ensuring the consistency of the design. This interdependence makes 3D models flexible and responsive to changes. One of the main advantages of parametric modeling lies in its ability to simplify customization and enable rapid iteration of designs.

Whether through modeling software such as Fusion 360 or FreeCAD, or through code-based libraries like build123d, this approach allows effortless exploration of a wide range of variations. Such flexibility is especially valuable across multiple fields—from mechanical engineering and architecture to consumer product design. It saves considerable time, reduces errors, and improves the performance of parts.

By defining design intent from the start through these parameters and constraints, the model preserves its integrity and functionality even after numerous modifications. It is a powerful way to transform an idea into a tangible object, ready to adapt to new situations.