3D printed biology models: DNA, cell, virus and bronchial tree
Pick a DNA helix, a cell, a virus or a bronchial tree, set the print size and download the model as STL or 3MF. Each model shows which numbers are measured and which were chosen for printing.
Opens without an account 3 times a day. A free account removes the limit.
- 5 modelsin 4 tabs
- From 2 nm to 50 µmplus airways in mm; scales on screen
- 0.8 mm thresholdthin features checked for FDM
- STL and 3MFfor the slicer
What 3D printed biology models are
Biology 3D is a free online tool from EduFacturing for 3D printed biology models. It builds five models: a B-DNA double helix, animal and plant cells in section, a virus capsid and a bronchial tree. Each is generated from maths in your browser, with no third-party 3D model inside.
The numbers come from cited sources, and the ones chosen for printing are marked on screen. A heart and a brain are not modelled: simple solids cannot describe them correctly.
Five biology models for a 3D printer
Builds a 3D printed DNA model
B-DNA with an outer diameter of 2 nm, a pitch of 3.4 nm and 10.5 base pairs per turn. The strands are offset by 120°: minor groove 120°, major 240°. Sliders cover 2 to 6 turns and a print diameter of 6 to 40 mm.
Builds a cell model in section
Animal (20 µm, nucleus 6 µm, 6 mitochondria) or plant (50 µm, nucleus 7 µm, vacuole 72% of the diameter, 6 chloroplasts). The model is a relief: a disc with raised organelles, not a hollow section.
Builds a virus and a bronchial tree
The virus is an icosahedron with a 25 nm capsid and 12 capsomer bumps (T=1: 12 pentamers of 5 subunits, 60 in all). The bronchial tree is symmetric, up to generation 10 (2047 tubes).
Checks that it will print
The thinnest feature is compared with the minimum FDM wall, 0.8 mm, and the figure is always shown, even when everything is fine.
When you need biology models for a lesson
From 2 nm to 50 µm: structures that become objects on a desk.
A biology lesson
A teacher prints a DNA helix and shows the grooves, or sets the two cells side by side: in the plant cell the vacuole is 72% of the diameter and the nucleus is pushed to the edge.
Viruses and immunology
The capsid has 12 capsomer bumps; the 60 subunits (12 pentamers of 5) are only in the numbers, not drawn. A virus is about 800 times smaller than an animal cell: 25 nm against 20 µm.
Breathing and physiology
The bronchial tree shows the diameter falling with each generation while the total cross-section grows: up to generation 6 it is 4 times that of the trachea.
Classroom or makerspace
A series of models at different sizes. The DNA helix is smoothest at a 0.12 to 0.16 mm layer height, and the flat cell needs no supports.
How the models are built and checked
The print size only scales the model: the proportions inside stay.
DNA
The axes of the two strands are helices of radius 0.5 diameters, the second offset by 120°, and the height grows by 1.7 diameters per turn. Base pairs are the rungs between the strands, 10.5 per turn.
Bronchial tree
Generation 0 is the trachea: 18 mm, 120 mm long at real size; the print model is scaled. Each next one splits in two at 35°, and the length is 6.67 diameters. Tubes are tapered.
Print check
The thinnest feature is compared with 0.8 mm for FDM from the rules core: below 0.8 mm the app warns that the feature will probably come out fused, and below 1.2 mm that it is close to the minimum wall.
| Applies to | Formula | Meaning |
|---|---|---|
| DNA: distance between base pairs | 3.4 nm / 10.5 | about 0.324 nm; pitch to diameter 3.4 / 2.0 = 1.70 |
| Airways: diameter | d(z) = 18 · 2^(−z/3) mm | z is the generation, 0 is the trachea; at z = 6 it is 4.50 mm at real size, and the print model is scaled |
| Airways: total cross-section | S(z) = 2^z · π · (d(z) / 2)² | grows 2^(z/3) times against the trachea: 4.0 times at z = 6 |
Measured numbers and numbers for printing
Numbers are separated by origin
The measured numbers are kept apart from those chosen for printing (backbone thickness, organelle count, capsomer size), which are marked as a visual choice.
The print check is always visible
The figure for the thinnest feature is on screen even when all is well, and for the tree it is measured in the model itself.
The cell is a schematic relief, not a hollow section: there are 6 mitochondria where a real cell has hundreds to thousands, and the chloroplast count (6) is also chosen for recognisability. The virus is T=1 only; higher T numbers are not modelled. The DNA backbone is thickened schematically for printing.
The bronchial tree is symmetric, goes to generation 10 and has no alveoli, while Weibel's model has 24 generations. Diameters follow the formula, an approximation of Weibel's model. Up to generation 6 and a height of 90 mm the thinnest point is 0.795 mm, below the FDM threshold.
Questions about 3D printed DNA, cell and virus models
How to make a dna model?
Open the DNA helix tab, set 2 to 6 turns and a print diameter of 6 to 40 mm, and download STL or 3MF.
How to make a cell model?
Pick an animal or plant cell, set the print size and download STL or 3MF. The model is a relief, not a hollow section.
What is a capsid?
A capsid is the protein shell of a virus. In the model it is an icosahedron with a 25 nm capsid and 12 capsomer bumps.
Where do the DNA proportions come from?
An outer diameter of 2 nm, a pitch of 3.4 nm and 10.5 base pairs per turn. The tool cites Watson and Crick (1953), Wang et al. (1979) and Calladine and Drew.
Why does the bronchial tree stop at generation 10?
The tubes number 2^(n+1) − 1, so 2047 up to generation 10, and printing cannot render a tube under about 0.8 mm. In Weibel's symmetric model the lung has 24 generations and about 16.8 million tubes.
How much do the 3D printed models cost?
They are free. The tool opens without an account 3 times a day, and a free account removes the limit.
The biology models is free. Pro opens the rest
Pro costs 15 EUR a month and opens 45 Pro tools.
In the Design group:
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Print your own DNA helix
Opens without an account 3 times a day. A free account removes the limit.