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Featured Model of the Day

Rectangular prism STL 3D file 100×70×29 mm 📦 #755

1 object(s) - format STL

gizmo

Latest user-generated 3D models

Round-to-Rectangular Tube Adapter STL 3D file ⌀50 mm to 34×12.5 mm, thickness 2 mm + offset 📦 #11406

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 #2574

2 object(s)
- format STL
Small parts organizer with 1 drawer 120×40×80 mm STL 3D file, thickness: 2 mm
Small parts organizer with 1 drawer 120×40×80 mm STL 3D file, thickness: 2 mm
View of object #0
Download this file of a drawer organizer in STL format. This model contains 1 compartment, arranged in 1 rows and 1 columns. Specifically, this means 1 rows of 1 compartments. Each compartment comes with an inner space of 120 mm wide, 40 mm high, and 80 mm deep. The wall thickness is 2 mm. The total size of the structure are 128.5 x 46.5 x 86 mm. All the objects in this model were designed to be printable without support generation.
Parameter Value Unit
number of rows 1
number of columns 1
inner drawer depth 80 mm
inner drawer width 120 mm
inner drawer height 40 mm
wall thickness 2 mm
removable divider none

📦 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 #3259

1 object(s)
- format STL
Tubing adapter STL file ⌀ 90–85 mm (Length: 39 mm)
Tubing adapter STL file ⌀ 90–85 mm (Length: 39 mm)
Tubing adapter ⌀90 mm to ⌀85 mm in STL 3D format. Final length of this junction is 39 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 18 mm, the smaller one of 16 mm. The ends are not rounded.
Parameter Value Unit
side A length 18 mm
side A outer diameter 90 mm
side A thickness 2 mm
side B length 16 mm
side B outer diameter 85 mm
side B thickness 2 mm
transition length 5 mm
axis offset 0 mm
ends fillet no fillet

📦 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 #3376

1 object(s)
- format STL
Round air vent STL 3D file ∅ 62 mm, slat angle: 40°
Round air vent STL 3D file ∅ 62 mm, slat angle: 40°
File of a round air vent for ventilation in STL format. Its insertion diameter measures 62 mm. The slats have an angle of 40° and a low thickness of 1.4 mm. This vent grille features a thin flange of 5 mm. The overall diameter of this model is 72 mm.
Parameter Value Unit
male diameter 62 mm
slat angle 40 °
slat thickness 1.4 mm
flange width 5 mm
central reinforcement no

📦 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

📦 Model #1026

1 object(s)
- format STL
Rectangular prism STL 3D file 25×25×40 mm and 5 mm fillets
Rectangular prism STL 3D file 25×25×40 mm and 5 mm fillets
A STL 3D model of a box. The final dimensions are 25 by 25 by 40 mm. A large fillet softens the edges.
Parameter Value Unit
length 25 mm
width 25 mm
height 40 mm
fillet radius 5 mm

📦 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 #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 #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 #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 #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 #2863

2 object(s)
- format STL
Small parts organizer with 20 drawers 45×25×25 mm STL 3D file, thickness: 2 mm
Small parts organizer with 20 drawers 45×25×25 mm STL 3D file, thickness: 2 mm
View of object #0
File of a multi-drawer box in 3D STL format. This model contains 20 drawers, arranged in 5 rows and 4 columns. Specifically, this means 5 rows of 4 drawers. Each drawer offers a storage volume of 45 mm wide, 25 mm high, and 25 mm deep. The wall thickness is 2 mm. The overall dimensions of the structure measure 208 x 149.5 x 31 mm. All the objects in this model were designed to be printed without support.
Parameter Value Unit
number of rows 5
number of columns 4
inner drawer depth 25 mm
inner drawer width 45 mm
inner drawer height 25 mm
wall thickness 2 mm
removable divider none

📦 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 #3263

1 object(s)
- format STL
Washer / Flat Gasket STL file ⌀ID: 42 mm ⌀OD: 46 mm thickness: 20 mm + fillet
Washer / Flat Gasket STL file ⌀ID: 42 mm ⌀OD: 46 mm thickness: 20 mm + fillet
Download this 3D file of gasket / washer in STL format. This model features an inner diameter of ⌀42 mm and an outer diameter of ⌀46 mm. The thickness is 20 mm. A fillet is applied on the inner diameter with a value of 1 mm.
Parameter Value Unit
inner diameter 42 mm
outer diameter 46 mm
thickness 20 mm
finish fillet
finish position inner
sides one side
finish value 1 mm

📦 Model #2623

2 object(s)
- format STL
Small parts organizer with 16 drawers 20×15×30 mm STL 3D file, thickness: 3 mm
Small parts organizer with 16 drawers 20×15×30 mm STL 3D file, thickness: 3 mm
View of object #0
Model of a multi-drawer unit in 3D STL format. This model includes 16 compartments, arranged in 4 rows and 4 columns. In detail, this means 4 rows of 4 compartments. Each compartment offers a storage volume of 20 mm wide, 15 mm high, and 30 mm deep. The wall thickness is 3 mm, which makes the structure solid. The overall dimensions of the structure are 121 x 89 x 39 mm. All the objects in this model are intended to be printed without support generation.
Parameter Value Unit
number of rows 4
number of columns 4
inner drawer depth 30 mm
inner drawer width 20 mm
inner drawer height 15 mm
wall thickness 3 mm
removable divider none

📦 Model #3364

1 object(s)
- format STL
Honeycomb grid STL file, center-to-center: 92x92mm, mesh: 8mm - Ø4mm
Honeycomb grid STL file, center-to-center: 92x92mm, mesh: 8mm - Ø4mm
3D honeycomb square grid model in STL format. Mounting holes are placed at the four corners (center-to-center 92x92 mm), each with a diameter of Ø4 mm. The overall dimensions reach 100x100 mm, with large 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 92 mm
width or center-to-center 92 mm
mesh size 8 mm
dual color no
holes yes
hole diameter 4 mm

📦 Model #2728

1 object(s)
- format STL
Tube adapter STL file ⌀ 150–100 mm (Length: 100 mm)
Tube adapter STL file ⌀ 150–100 mm (Length: 100 mm)
Straight tube fitting ⌀150 mm to ⌀100 mm in STL 3D format. Length of this adapter is 100 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a length of 20 mm, the smaller one of 30 mm. The ends have no fillet.
Parameter Value Unit
side A length 20 mm
side A outer diameter 150 mm
side A thickness 3 mm
side B length 30 mm
side B outer diameter 100 mm
side B thickness 3 mm
transition length 50 mm
axis offset 0 mm
ends fillet no fillet

📦 Model #1057

1 object(s)
- format STL
O-ring STL file ID 50 × CS 2.5 mm
O-ring STL file ID 50 × CS 2.5 mm
3D file in STL format of rubber ring with ID (inner diameter) 50 mm / thickness 2.5 mm. Outer diameter (OD) resulting corresponds to 55 mm.
Parameter Value Unit
inner diameter (ID) 50 mm
cross section (CS) 2.5 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 #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 #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 #1082

1 object(s)
- format STL
Multi-compartment box STL 3D file: 4 compartments of 35×35×35 mm
Multi-compartment box STL 3D file: 4 compartments of 35×35×35 mm
This parametric storage box provides 4 cavities measuring 35×35×35mm each. External size of the box are 79×79×38mm. Fillets of 3mm applied to each compartment provide a better grip stored in the box. The walls are particularly thick.
Parameter Value Unit
number of rows 2
number of columns 2
compartment length 35 mm
compartment width 35 mm
compartment height 35 mm
wall thickness 3 mm
compartment fillet (radius) 3 mm

📦 Model #4429

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL 3D file ⌀103 mm to 290×28 mm, thickness 3 mm
Round-to-Rectangular Tube Adapter STL 3D file ⌀103 mm to 290×28 mm, thickness 3 mm
Download this model in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀103 mm and a rectangular section with internal dimensions 290×28 mm. The wall thickness is 3 mm and the total length is 148 mm.
Parameter Value Unit
cylinder outer diameter 103 mm
cylinder inlet length 50 mm
rectangle internal length 290 mm
rectangle internal height 28 mm
rectangle inlet length 50 mm
offset Z 0 mm
offset Y 0 mm
total length 148 mm
thickness 3 mm
chamfer no chamfer

📦 Model #1868

1 object(s)
- format STL
Tube adapter STL file ⌀ 116–100 mm (Length: 113 mm)
Tube adapter STL file ⌀ 116–100 mm (Length: 113 mm)
Tube adapter ⌀116 mm to ⌀100 mm in STL 3D format. Length of this junction is 113 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 50 mm, the smaller one of 50 mm as well. The ends are not rounded.
Parameter Value Unit
side A length 50 mm
side A outer diameter 116 mm
side A thickness 3 mm
side B length 50 mm
side B outer diameter 100 mm
side B thickness 3 mm
transition length 13 mm
axis offset 0 mm
ends fillet no fillet

📦 Model #4144

1 object(s)
- format STL
Honeycomb grille STL 3D file, 195x80mm, mesh: 4mm
Honeycomb grille STL 3D file, 195x80mm, mesh: 4mm
Download this 3D rectangular protective grid file in STL format. The overall size is 195x80 mm, with medium 4 mm cell size for versatile use. This grid provides both mechanical protection and airflow.
Parameter Value Unit
length or center-to-center 195 mm
width or center-to-center 80 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 #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 #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 #1853

1 object(s)
- format STL
Multi-compartment box STL 3D file: 5 compartments of 35×45×15 mm
Multi-compartment box STL 3D file: 5 compartments of 35×45×15 mm
This multi-compartment box design provides 5 cavities measuring 35×45×15mm each. The total dimensions of the box are 39×237×17mm. Fillets of 10mm applied to each compartment help with item retrieval stored in slots.
Parameter Value Unit
number of rows 5
number of columns 1
compartment length 35 mm
compartment width 45 mm
compartment height 15 mm
wall thickness 2 mm
compartment fillet (radius) 10 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.