3D-printed-parametric-40mm-gas-mask-canister/Readme.md

# 3D Printed parametric 40mm gas-mask canister

## _Cartouche paramétrique de masque à gaz de 40mm imprimé en 3D (**version francaise [ici](./Readme.fr.md)**)_

_\[**English version automatically spell checked with minimum effort put into proofreading**\]_

[![fr](https://img.shields.io/badge/lang-fr-red.svg)](./Readme.fr.md)
[![en](https://img.shields.io/badge/lang-en-green.svg)](./Readme.md)

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_picture.png?raw=true" alt="Image not available" height="400" />

Here is the [printable page](https://www.printables.com/model/1114061-parametric-40mm-gas-mask-canister) for this model.

## 1 - Design and usage

:warning: **WARNING : _Please don't use a 3D printed canister (or even our mask) in life threatening situations !_** :warning:

This canister is made to be used with mask supporting standard 40mm threaded canisters - sometimes also known as "_nato threaded_" canisters - which the standard dimensions are defined in [sources/nato_thread_spec.png](./sources/nato_thread_spec.png).

This filter canister works by holding a filtering material - _usually activated charcoal_ - in between two securely held mask/filter pieces.

The center sleeve is made to hold both the mask/filter pieces, using the pressure of the two outer shell part being screwed in together around the sleeve.

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_plug_picture.png?raw=true" alt="Image not available" height="200" />

This repository also provides a _plug_ to use instead of a canister for masks that have two threads for canister - _like the one we provide at_ [distorsion/3D-printed-parametric-gas-mask](https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-gas-mask) - which you can print from the [3Dfiles/nato_thread_plug.stl](./3Dfiles/) file.

## 2 - Assembly

Once you have printed all the required pieces as described in the [_3D printing section_](#3-3d-printing), the assembly is simply done in three steps :

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_asembly_step1.png?raw=true" alt="Image not available" height="300" />

You can first put your (_covid/chirurgical_) mask or filter and put it in the _cap_ or at the top of the _sleeve_, with 0.5/1cm extra material all around the _sleeve_.

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_asembly_step2.png?raw=true" alt="Image not available" height="300" />

Secondly, you can push in the _sleeve_ within the _cap_ making sure that the whole surface of the mask/filter is firmly held and that there are no holes.

You can then fill the _sleeve_ with your filter material : typically activated charcoal which can be source **cheaply** from activated charcoal for aquarium filter.

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_asembly_step3.png?raw=true" alt="Image not available" height="300" />

Finally you can repeat the first step with the top of the _sleeve_, putting a mask/filter, then pushing the _sleeve_/_cap_ assembly into the _main body_ before screwing the _cap_ and _main body_ together, thus securely holding the sleeve and he two mask/filter holding the filtering material in place.

## 3 - 3D printing

<img src="https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-40mm-gas-mask-canister/media/branch/main/pictures/canister_sliced.png?raw=true" alt="Image not available" height="400" />

To assemble a full canister, you need to need to print :
 - 1 _sleeve_ from [3Dfiles/canister_sleeve.stl](./3Dfiles/)
 - 1 _cap_ from [3Dfiles/canister_cap.stl](./3Dfiles/)
 - 1 _main body_ from [3Dfiles/canister_main_body.stl](./3Dfiles/)

You can also print a _plug_ to use instead of a canister for masks that have two threads for canister - _like the one we provide at_ [distorsion/3D-printed-parametric-gas-mask](https://git.deuxfleurs.fr/distorsion/3D-printed-parametric-gas-mask) - which you can print from the [3Dfiles/nato_thread_plug.stl](./3Dfiles/) file.

There is no particular printing parameters or material requirements to make this canister properly work. Note that every file provided can be printed without support :
 - print the _plug_ ([3Dfiles/nato_thread_plug.stl](./3Dfiles/)) with the flat face facing down.
 - print the _sleeve_ with one of the open end pointing down.
 - print the _cap_ with the flat face pointing down.
 - print the _main body_ with the 40mm thread pointing down, you can add a skirt to support it better if you fear it falling over mid-print.

## 4 - Parameters

If you want to changes the parameters of this design, you can edit the _Freecad_ file [3Dfiles/40mm_gas_mask_canister.FCStd](./3Dfiles/), which is fully parametric, with parameters present in the **Spreadsheet**.

If you want/need to change parameters, we would suggest you play with them and try to understand the impact of each parameters. We will only explain a small selection of important parameters that you are most likely to have to edit.

We will only describe a few parameters that you are most likely to have to change.

### 4.a - Structural parameters

_**wall_thickness** :_ \[_default=2.7mm_\] The wall thickness across the print (_except for the strap attachment point_). Can be tweaked to make the print either stronger or weaker but lighter and faster to print.

_**snap_fit_clearance** :_ \[_default=0.09mm_\] The clearance between two objects that would fit together with difficulty. Also impact the clearance between threads.

### 4.b - Geometrical parameters

The two most important parameters that you would probably have to tweak for your usage are :

_**filter_diameter** :_ \[_default=55mm_\] interior diameter of the filter, the larger the diameter the easier breathing will be, but also the better filtering will be as air will pass more slowly through the filter for the same air flow, thus making the filter more effective. A larger filter will be heavier and thus be less comfortable.

_**filter_length** :_ \[_default=35mm_\] interior length of the filter, the longer the filter will be, the better the filter will work but also the harder it will be to breath. A longer filter will be heavier and thus be less comfortable.

## License

```
"3D Printed parametric 40mm gas-mask canister" (c) by @distorsion

"3D Printed parametric 40mm gas-mask canister" is licensed under a
Creative Commons Attribution 4.0 International License.

You should have received a copy of the license along with this
work. If not, see <https://creativecommons.org/licenses/by/4.0/>.
```