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Featured Model of the Day

Pipe elbow STL 3D file 30° ⌀OD: 50 mm ⌀ID: 46 mm thickness: 2 mm 📦 #1363

1 object(s) - format STL

gizmo

Latest user-generated 3D models

Tube STL file OD 9 mm, ID 5 mm, length 22 mm 📦 #11034

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 #3015

2 object(s)
- format STL
Honeycomb grid STL 3D file, center-to-center: 70x70mm, mesh: 10mm - Ø4mm
Honeycomb grid STL 3D file, center-to-center: 70x70mm, mesh: 10mm - Ø4mm
View of object #0
3D square grid model as a STL file. Mounting holes are placed at the four corners (center-to-center 70x70 mm), each with a diameter of Ø4 mm. The overall dimensions reach 78x78 mm, with extra wide 10 mm cell size for maximum airflow. A secondary color frame emphasizes the border. This grid serves as both a protective guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 70 mm
width or center-to-center 70 mm
mesh size 10 mm
dual color yes
holes yes
hole diameter 4 mm

📦 Model #4060

1 object(s)
- format STL
Pipe elbow STL file 150° ⌀OD: 76 mm ⌀ID: 70 mm thickness: 3 mm
Pipe elbow STL file 150° ⌀OD: 76 mm ⌀ID: 70 mm thickness: 3 mm
Model of a pipe elbow with a 150° angle in STL format. This elbow features an external diameter of 76 mm and an internal diameter of 70 mm. This results in a tube thickness of 3 mm. End fillets make it easier to assemble.
Parameter Value Unit
outer diameter 76 mm
inner diameter 70 mm
angle 150 °
end fillets yes

📦 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 #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 #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

📦 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 #2497

1 object(s)
- format STL
Pot STL 3D file, inner: base Ø40 mm, top Ø200 mm, height 40 mm - wall thickness 1 mm
Pot STL 3D file, inner: base Ø40 mm, top Ø200 mm, height 40 mm - wall thickness 1 mm
Download this 3D model of a bowl in STL format. This model can be used for sorting small parts in a workshop or on a desk. The shape is very flared, with a internal height of 40 mm, a internal diameter at the top of 200 mm, and a internal diameter at the bottom of 40 mm. The bowl height is 41 mm.
Parameter Value Unit
inner bottom diameter 40 mm
inner top diameter 200 mm
inner height 40 mm
wall thickness 1 mm

📦 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 #4109

1 object(s)
- format STL
Multi-compartment box STL file: 12 compartments of 16×16×40 mm
Multi-compartment box STL file: 12 compartments of 16×16×40 mm
This STL 3D model includes 12 slots measuring 16×16×40mm each. The total dimensions are 110×38×42mm.
Parameter Value Unit
number of rows 2
number of columns 6
compartment length 16 mm
compartment width 16 mm
compartment height 40 mm
wall thickness 2 mm
compartment fillet (radius) 1 mm

📦 Model #3342

1 object(s)
- format STL
Protective grid STL file, 70x46mm, mesh: 4mm
Protective grid STL file, 70x46mm, mesh: 4mm
3D honeycomb rectangular grid model in STL format. The overall size is 70x46 mm, with standard 4 mm cell size for balanced airflow and protection. This grid functions as both a mechanical guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 70 mm
width or center-to-center 46 mm
mesh size 4 mm
dual color no
holes 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 #1471

2 object(s)
- format STL
Round box with lid STL file ⌀ 80 mm - Height: 35 mm, Shell: 3 mm
Round box with lid STL file ⌀ 80 mm - Height: 35 mm, Shell: 3 mm
View of object #0
Download this round storage box in 3D STL format. Its diameter is 80 mm and its height is 35 mm. The wall thickness is 3 mm.
Parameter Value Unit
external diameter 80 mm
total height 35 mm
wall thickness 3 mm
fit clearance 0.1 mm
inner bottom fillet 0 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 #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 #1523

1 object(s)
- format STL
Tube adapter STL file ⌀ 33–10 mm (Length: 250 mm)
Tube adapter STL file ⌀ 33–10 mm (Length: 250 mm)
Tube junction ⌀33 mm to ⌀10 mm in STL 3D format. Final length of this fitting is 250 mm. The larger-diameter tube has a thickness of 2.9 mm and a length of 15 mm. The smaller-diameter tube has a thickness of 2 mm and a length of 230 mm. The ends have no fillet.
Parameter Value Unit
side A length 15 mm
side A outer diameter 33 mm
side A thickness 2.9 mm
side B length 230 mm
side B outer diameter 10 mm
side B thickness 2 mm
transition length 5 mm
axis offset 0 mm
ends fillet no fillet

📦 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 #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 #4519

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL 3D file ⌀52 mm to 50×41 mm, thickness 2 mm
Round-to-Rectangular Tube Adapter STL 3D file ⌀52 mm to 50×41 mm, thickness 2 mm
Download this 3D model in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀52 mm and a rectangular section with internal dimensions 50×41 mm. The wall thickness is 2 mm and the overall length is 50 mm. A chamfer is applied on the outside of the cylindrical end.
Parameter Value Unit
cylinder outer diameter 52 mm
cylinder inlet length 10 mm
rectangle internal length 50 mm
rectangle internal height 41 mm
rectangle inlet length 7 mm
offset Z 0 mm
offset Y 0 mm
total length 50 mm
thickness 2 mm
chamfer chamfer on t...

📦 Model #3546

1 object(s)
- format STL
Corner bracket 200×120 mm STL 3D file, thickness 8 mm, hole diameter 6 mm
Corner bracket 200×120 mm STL 3D file, thickness 8 mm, hole diameter 6 mm
Model of a support bracket with a central reinforcement in STL format. The dimensions are 200 mm in length, 120 mm in height, 20 mm in width, and 8 mm in thickness. The holes have a diameter of 6 mm. Chamfers are done to the holes to seat the screw heads. The reinforcing bar enhances mechanical strength and includes two passages for fastening. This bracket prints without support, printed flat directly on the build plate.
Parameter Value Unit
length 200 mm
height 120 mm
width 20 mm
thickness 8 mm
hole diameter 6 mm
chamfer on the holes yes

📦 Model #958

1 object(s)
- format STL
U-shaped handle STL 3D file 50×140×10 mm (Center-to-center 130 mm)
U-shaped handle STL 3D file 50×140×10 mm (Center-to-center 130 mm)
Download this STL file of a simple U-shaped furniture handle. The external dimensions are 50×140×10 mm. This handle features a square section combined with a straight transition. The holes are 4 mm diameter with a center-to-center distance of 130 mm.
Parameter Value Unit
width 50 mm
length 140 mm
thickness 10 mm
shape (0:square,1:circle) 0
transition (0:right,1:rounded) 0
fillet radius 0 mm
hole diameter 4 mm

📦 Model #1712

1 object(s)
- format STL
Washer / Flat Gasket STL file ⌀ID: 60 mm ⌀OD: 80 mm thickness: 10 mm + chamfers
Washer / Flat Gasket STL file ⌀ID: 60 mm ⌀OD: 80 mm thickness: 10 mm + chamfers
Download this 3D model of flat gasket / washer in STL format. This part features an inner diameter of ⌀60 mm and an outer diameter of ⌀80 mm. The total thickness is 10 mm. Chamfers are applied on both the inner diameter and the outer diameter, each with a value of 4.9 mm. These finishes are present on both faces.
Parameter Value Unit
inner diameter 60 mm
outer diameter 80 mm
thickness 10 mm
finish chamfer
finish position inner + oute...
sides two sides
finish value 4.9 mm

📦 Model #2559

1 object(s)
- format STL
Pipe elbow STL file 90° ⌀OD: 41 mm ⌀ID: 38 mm thickness: 1.5 mm
Pipe elbow STL file 90° ⌀OD: 41 mm ⌀ID: 38 mm thickness: 1.5 mm
Model of a pipe elbow with a 90° angle in STL format. This elbow has an outer diameter of 41 mm and an inner diameter of 38 mm. The tube thickness is therefore 1.5 mm. End fillets make it easier to assemble.
Parameter Value Unit
outer diameter 41 mm
inner diameter 38 mm
angle 90 °
end fillets 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 #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 #1910

1 object(s)
- format STL
Multi-compartment box STL file: 6 compartments of 100×60×30 mm
Multi-compartment box STL file: 6 compartments of 100×60×30 mm
This STL file features 6 storage spaces measuring 100×60×30mm each. Overall dimensions of the box are 207.2×189.6×32.4mm. The compartments lack any fillet.
Parameter Value Unit
number of rows 3
number of columns 2
compartment length 100 mm
compartment width 60 mm
compartment height 30 mm
wall thickness 2.4 mm
compartment fillet (radius) 0 mm

📦 Model #1948

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL 3D file ⌀30 mm to 29×19 mm, thickness 2 mm
Round-to-Rectangular Tube Adapter STL 3D file ⌀30 mm to 29×19 mm, thickness 2 mm
Download this file in STL format of a round-to-rectangular adapter with an outer diameter of ⌀30 mm and a rectangular section with inner dimensions 29×19 mm. The shell thickness is 2 mm and the overall length is 50 mm.
Parameter Value Unit
cylinder outer diameter 30 mm
cylinder inlet length 20 mm
rectangle internal length 29 mm
rectangle internal height 19 mm
rectangle inlet length 8 mm
offset Z 0 mm
offset Y 0 mm
total length 50 mm
thickness 2 mm
chamfer no chamfer

📦 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 #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 #3724

1 object(s)
- format STL
Protective grid STL 3D file, center-to-center: 300x106mm, mesh: 10mm - Ø6mm
Protective grid STL 3D file, center-to-center: 300x106mm, mesh: 10mm - Ø6mm
Download this 3D honeycomb protective rectangular grid model in STL format. Mounting holes are placed at the four corners (center-to-center 300x106 mm), each with a diameter of Ø6 mm. The overall dimensions reach 312x118 mm, with very large 10 mm cell size for maximum airflow. This grid functions as both a mechanical guard and a ventilation panel.
Parameter Value Unit
length or center-to-center 300 mm
width or center-to-center 106 mm
mesh size 10 mm
dual color no
holes yes
hole diameter 6 mm

📦 Model #3911

1 object(s)
- format STL
Multi-compartment box STL file: 4 compartments of 50×50×100 mm
Multi-compartment box STL file: 4 compartments of 50×50×100 mm
This printable sectioned box provides 4 slots measuring 50×50×100mm each. The total dimensions of the box are 115×115×105mm. A 2mm fillet applied to all compartments provide a better grip stored in the compartments. The walls are particularly reinforced.
Parameter Value Unit
number of rows 2
number of columns 2
compartment length 50 mm
compartment width 50 mm
compartment height 100 mm
wall thickness 5 mm
compartment fillet (radius) 2 mm

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.