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Featured Model of the Day

Color-coded compartment box STL 3D file: 16 compartments of 25×25×25 mm 📦 #1196

3 object(s) - format STL

gizmo

Latest user-generated 3D models

Washer / Flat Gasket STL file ⌀ID: 36 mm ⌀OD: 46 mm thickness: 5 mm 📦 #9944

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 #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 #4512

1 object(s)
- format STL
Tube elbow STL file 45° ⌀OD: 40 mm ⌀ID: 25 mm thickness: 7.5 mm
Tube elbow STL file 45° ⌀OD: 40 mm ⌀ID: 25 mm thickness: 7.5 mm
3D model of an elbow with a 45° angle in STL format. This pipe elbow has an external diameter of 40 mm and an internal diameter of 25 mm. The tube thickness is therefore 7.5 mm.
Parameter Value Unit
outer diameter 40 mm
inner diameter 25 mm
angle 45 °
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 #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 #4035

1 object(s)
- format STL
Shelf bracket 200×120 mm STL file, thickness 12 mm, hole diameter 6 mm
Shelf bracket 200×120 mm STL file, thickness 12 mm, hole diameter 6 mm
Download this 3D file of a corner bracket reinforced in STL 3D format. The dimensions are 200 mm in length, 120 mm in height, 50 mm in width, and 12 mm in thickness. The drill holes have a diameter of 6 mm. Chamfers are done to the holes for a cleaner fit of the screws. The reinforcing bar reduces bending and provides two openings for fastening. This bracket prints without support, placed flat directly on the build plate.
Parameter Value Unit
length 200 mm
height 120 mm
width 50 mm
thickness 12 mm
hole diameter 6 mm
chamfer on the holes yes

📦 Model #2477

1 object(s)
- format STL
Round-to-Rectangular Tube Adapter STL 3D file ⌀27 mm to 33×30 mm, thickness 2 mm
Round-to-Rectangular Tube Adapter STL 3D file ⌀27 mm to 33×30 mm, thickness 2 mm
Download this file in STL format of a round-to-rectangular adapter with an external diameter of ⌀27 mm and a rectangular section with internal dimensions 33×30 mm. The wall thickness is 2 mm and the overall length is 115 mm.
Parameter Value Unit
cylinder outer diameter 27 mm
cylinder inlet length 20 mm
rectangle internal length 33 mm
rectangle internal height 30 mm
rectangle inlet length 75 mm
offset Z 0 mm
offset Y 0 mm
total length 115 mm
thickness 2 mm
chamfer no chamfer

📦 Model #4227

1 object(s)
- format STL
Tubing adapter STL 3D file ⌀ 73–51 mm (Length: 150 mm)
Tubing adapter STL 3D file ⌀ 73–51 mm (Length: 150 mm)
Tube reducer ⌀73 mm to ⌀51 mm in STL format. Length of this coupler is 150 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a sleeve length of 50 mm, the smaller one of 50 mm as well. The ends are raw.
Parameter Value Unit
side A length 50 mm
side A outer diameter 73 mm
side A thickness 2 mm
side B length 50 mm
side B outer diameter 51 mm
side B thickness 2 mm
transition length 50 mm
axis offset 0 mm
ends fillet no fillet

📦 Model #2891

1 object(s)
- format STL
Tubing adapter STL 3D file ⌀ 148–135 mm (Length: 90 mm)
Tubing adapter STL 3D file ⌀ 148–135 mm (Length: 90 mm)
Tubing reducer ⌀148 mm to ⌀135 mm in STL format. Total length of this connector is 90 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 20 mm, the smaller one of 50 mm. The ends are not rounded.
Parameter Value Unit
side A length 20 mm
side A outer diameter 148 mm
side A thickness 3 mm
side B length 50 mm
side B outer diameter 135 mm
side B thickness 3 mm
transition length 20 mm
axis offset 0 mm
ends fillet no fillet

📦 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 #1681

1 object(s)
- format STL
O-ring STL 3D file ID 70 × CS 4 mm
O-ring STL 3D file ID 70 × CS 4 mm
STL file of sealing ring with dimensions Internal diameter 70 mm / CS 4  mm. External diameter (OD) is therefore 78 mm.
Parameter Value Unit
inner diameter (ID) 70 mm
cross section (CS) 4 mm

📦 Model #4242

2 object(s)
- format STL
Small parts organizer with 400 drawers 150×150×150 mm STL 3D file, thickness: 4 mm
Small parts organizer with 400 drawers 150×150×150 mm STL 3D file, thickness: 4 mm
View of object #0
File of a sorting cabinet with drawers in 3D STL format. This model features 400 boxes, arranged in 20 rows and 20 columns. Practically speaking, this means 20 rows of 20 boxes. Each box comes with an inner space of 150 mm wide, 150 mm high, and 150 mm deep. The wall thickness is 4 mm, which makes the structure very sturdy. The overall dimensions of the structure come to 3254 x 3174 x 162 mm. All the objects in this model are intended to be printable without support generation.
Parameter Value Unit
number of rows 20
number of columns 20
inner drawer depth 150 mm
inner drawer width 150 mm
inner drawer height 150 mm
wall thickness 4 mm
removable divider none

📦 Model #4348

1 object(s)
- format STL
Tubing adapter STL 3D file ⌀ 33–14 mm (Length: 40 mm)
Tubing adapter STL 3D file ⌀ 33–14 mm (Length: 40 mm)
Tubing reducer ⌀33 mm to ⌀14 mm in STL format. Length of this coupler is 40 mm. The larger-diameter tube has a thickness of 2.5 mm and a sleeve length of 15 mm. The smaller-diameter tube has a thickness of 2 mm and a length of 15 mm as well. The ends have no fillet.
Parameter Value Unit
side A length 15 mm
side A outer diameter 33 mm
side A thickness 2.5 mm
side B length 15 mm
side B outer diameter 14 mm
side B thickness 2 mm
transition length 10 mm
axis offset 0 mm
ends fillet no fillet

📦 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 #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 #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 #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 #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 #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 #2506

3 object(s)
- format STL
Small parts organizer with 9 drawers 119×60×150 mm STL 3D file, thickness: 4 mm
Small parts organizer with 9 drawers 119×60×150 mm STL 3D file, thickness: 4 mm
View of object #0
Download this file of a storage organizer in STL format. This model contains 9 drawers, arranged in 3 rows and 3 columns. Practically speaking, this means 3 rows of 3 drawers. Each drawer comes with an inner space of 119 mm wide, 60 mm high, and 150 mm deep. The wall thickness is 4 mm, which makes the structure very solid. The drawers include 1 divider each, which allows up to 2 compartments per drawer and up to 18 compartments in total. The external dimensions of the box measure 398.5 x 209.5 x 162 mm. All the objects in this model are intended to be printed without support.
Parameter Value Unit
number of rows 3
number of columns 3
inner drawer depth 150 mm
inner drawer width 119 mm
inner drawer height 60 mm
wall thickness 4 mm
removable divider one divider ...

📦 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 #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 #2997

1 object(s)
- format STL
Corner bracket 250×250 mm STL file, thickness 10 mm, hole diameter 8 mm
Corner bracket 250×250 mm STL file, thickness 10 mm, hole diameter 8 mm
Download this 3D model of a support bracket with a reinforcing bar in STL format. The dimensions are 250 mm in length, 250 mm in height, 30 mm in width, and 10 mm in thickness. The mounting holes have a diameter of 8 mm. Chamfers are done to the holes for a cleaner fit of the screws. The reinforcing bar reduces bending and includes two passages for screwdriver access. This bracket prints without support, placed flat on the build plate.
Parameter Value Unit
length 250 mm
height 250 mm
width 30 mm
thickness 10 mm
hole diameter 8 mm
chamfer on the holes 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 #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 #3356

1 object(s)
- format STL
Clip-on pipe holder Ø32 mm STL 3D file · Round head screw Ø4 mm
Clip-on pipe holder Ø32 mm STL 3D file · Round head screw Ø4 mm
3D model of a Ø32 mm pipe clip in STL format. The fastening is done using a pan head screw Ø4 mm. This custom pipe clip is designed for a firm hold with easy setup.
Parameter Value Unit
tube diameter 32 mm
hole diameter 4 mm
countersunk screw no

📦 Model #3627

1 object(s)
- format STL
Honeycomb grid STL file, center-to-center: 168x63mm, mesh: 3mm - Ø3mm
Honeycomb grid STL file, center-to-center: 168x63mm, mesh: 3mm - Ø3mm
Download this 3D rectangular honeycomb grid as a STL file. Mounting holes are placed at the four corners (center-to-center 168x63 mm), each with a diameter of Ø3 mm. The overall dimensions reach 174x69 mm, with extra fine 3 mm cell size for strong protection. This grid provides both mechanical protection and airflow.
Parameter Value Unit
length or center-to-center 168 mm
width or center-to-center 63 mm
mesh size 3 mm
dual color no
holes yes
hole diameter 3 mm

📦 Model #1306

1 object(s)
- format STL
Multi-compartment box STL file: 30 compartments of 55×45×45 mm
Multi-compartment box STL file: 30 compartments of 55×45×45 mm
This 3D model in STL format provides 30 cavities measuring 55×45×45mm each. The total dimensions of the box are 287×284×47mm.
Parameter Value Unit
number of rows 6
number of columns 5
compartment length 55 mm
compartment width 45 mm
compartment height 45 mm
wall thickness 2 mm
compartment fillet (radius) 0.5 mm

📦 Model #2604

1 object(s)
- format STL
Pipe elbow STL 3D file 35° ⌀OD: 55 mm ⌀ID: 51 mm thickness: 2 mm
Pipe elbow STL 3D file 35° ⌀OD: 55 mm ⌀ID: 51 mm thickness: 2 mm
3D file of a tubing elbow with a 35° angle in STL format. This pipe elbow features an external diameter of 55 mm and an internal diameter of 51 mm. This results in a tube thickness of 2 mm. The ends feature fillets to make it easier to assemble.
Parameter Value Unit
outer diameter 55 mm
inner diameter 51 mm
angle 35 °
end fillets yes

📦 Model #3151

1 object(s)
- format STL
Multi-compartment box STL 3D file: 6 compartments of 7.6×7.6×29 mm
Multi-compartment box STL 3D file: 6 compartments of 7.6×7.6×29 mm
This STL file includes 6 compartments measuring 7.6×7.6×29mm each. The total dimensions are 24.5×35.2×32.1mm. A 3mm fillet applied to each compartment make it easier to grasp items stored in the compartments. The walls are particularly thick.
Parameter Value Unit
number of rows 3
number of columns 2
compartment length 7.6 mm
compartment width 7.6 mm
compartment height 29 mm
wall thickness 3.1 mm
compartment fillet (radius) 3 mm

📦 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

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.