Silvana Decathlon face mask adapters

The Silvana adapter for Decathlon face masks can be used for CPAP assistance to help fight the COVID-19 disease. The functional design is inspired on Charlotte valve from Italy, redesigned from scratch with the philosophy of making it directly printable as clean as possible on commonday 3D printers.

Project information: http://help4corona.eu/

A new injection-mould version is also available: https://www.prusaprinters.org/prints/37677-injection-mould-silvana-decathlon-mask-adapter-wit

Originally there were four configurations: Small / Small-d / Large / Large-d. From April 6, 2020 many more configurations are available.

The more common "Small" version fits Decathlon Subea model 1 (white connector, size approx. 45x19 mm).
The relatively new "Large" version, from v1.0 having configuration "W" fits Decathlon Subea model 2 (transparent connector, size approx. 53x23 mm).

The "D" configuration (prior to v1.0 indicated by suffix "-d") indicates that exhaust port has 22M port size (conical 22 mm male) for standard ventilation equipment.

The "C" configuration (prior to v1.0 without "-d" suffix) the exhaust port has outer diameter 19.4 mm, matching specific ventilation valves as used in the original Charlotte adapter design from Italy and from v1.0 having depth 20 mm and tapered 1.43° (1:40).

"F" indicates 22F output port; "FF" also has a 22F input port; "FFF" has three 22F ports

"T" (from v1.0) indicates dual input port, making three in total.

"X" also uses dual port of which one is horizontal; this is the only configuration which needs supports during printing.

"L" indicates loose fit, to be used if the normal version is too tight due to dimensional variations.

"N" (till v1.1 only): indicates no support structures are included, to be used for 3D printers which do not need supports (or generate these already). From v1.2 supports are not needed for the small adapter.

The following configuration combinations are available for direct download:
C, CL, D, DL, F, FL, TD, TDL, TF, TFL,
CW, DW, FW, FFW, TCW, TDW, TFFW, TFFFW, XFFW

Single-port output for "PPE" purposes (be warned about effectiveness): check https://www.prusaprinters.org/prints/29147-valentine-decathlon-face-mask-adapters

Decathlon masks come in five different sizes, but it seems that the connector type is not directly related to mask size. The "small" size is the old, mainstream version. The "large" size is relatively new.

NO supports needed. 0.2 mm layer height is fine. After printing (v1.1 and earlier): remove the support parts (X or L shaped). Do not attempt to remove the square-shaped central shaft in v1.2 and later.

Developed by Robotics and Mechatronics, University of Twente, in close collaboration with TechMed (UT), IHU Strasbourg and various other partners.

Feature requests are welcome, e.g. a configuration with specific port in different length or connector size. E-mail groenhuis@gmail.com to discuss.

Changelog:

-- Small version: --
v1.4 April 17: Redesigned rubber seal opening based on accurate high-resolution photographs for better sealing; optimized dimensions of rigid clamping elements; fixed incomplete attachment of RaM logo
v1.3 April 9: Corrected 22M/22F connectors with proper taper angle (was 1:20, now 1:40)
v1.2 April 7: Redesigned central shaft, eliminated supports
and "N" configuration, reshaped steep overhangs, increased wall thickness in "C" configuration
v1.1 April 6: DLN, FL, TFL configurations: fixed configuration inconsistencies
v1.0 April 6: Rebranding to "Silvana" name, release of v1.0, new configuration scheme. Added 3-port and 22F (22 mm conical female) exhaust port variants. Tightness of non-"L" model improved. 22M tubes start at 21.7 mm instead of 21.5 mm for better fit with external pieces. The "C" configuration (20M exhaust) has longer fitting and is now tapered, to fit external pieces better.
v0.8.7_Loose April 3: Slight modification of v0.8.7 with loose fit, in case v0.8.7 is too tight due to dimensional variations. (Model labeled "v0.8.7L")
v0.8.7 April 2: Text embossed instead of debossed to avoid (too) thin walls at locations of text
v0.8.6 April 1: Redesigned clamping mechanism: tapered walls for rigid claming and rubber ring now only for sealing. Adapter is now easier to push in fitting.
v0.8.5.1 March 30: Fixed error in small-d_v0.8.5 (wrong connector type exported) (warning: v0.8.5(.1) is (too) tight!)
v0.8.5 March 30 Adjusted mask-adapter connection to improve tightness; tapered intake port mask-adapter connection for improved sealing; adjusted output ports to conform to ISO5356-1 (22 mm tapered); resolved slicing error (warning: v0.8.5(.1) is (too) tight!)
v0.8.4 March 29 Output ports conical: 22 mm 1°
v0.8.3 March 29 Eliminated bridges / difficult overhangs in intake airway
v0.8.2 March 27, Extra room for rubber ring around mask connector
v0.8.1 March 27, Small fix to improve printability of bridge
v0.8 March 27, Improved small version, better attachment, wider connection left/right side, exhaust connection angled further away to allow 2 filters, thinner walls so less material needed so you can print solid.
v0.7 March 26: first version but note that attachment does not separate intake/exhaust properly yet.

-- Large version: --
v1.4 Redesigned rubber seal opening based on accurate high-resolution photographs for better sealing
v1.1b April 11: Published FFW, TFFFW, XFFW configurations
v1.1b April 9: Published FW, TDW, TCW, TFFW configurations; put "Front"/"Back" signs on body; put flow direction arrows on certain configurations
v1.0 April 6: Renamed to "Silvana", from v1.0 the "Large" version is indicated by the "W" configuration in the name, e.g. "Silvana-DW-1.0"
v0.9.8 March 30: Adjusted output ports to conform to ISO5356-1 (22 mm tapered); tapered intake port mask-adapter connection for improved sealing; resolved slicing error; moved texts to higher position to avoid thin walls
v0.9.7 March 29: Output ports conical 22 mm 1°
v0.9.6 March 29: Removed last patch of bridging in intake port
v0.9.5 March 28: Minor adjustments
v0.9.4 March 28: Improved printabilty
v0.9.3 March 28: Fixed printing imperfections
v0.9.2 March 28: Fixed inconsistent wall thickness on exhaust port
v0.9.1 March 28: Reinforced potential weak spot
v0.9 March 28: improved sealing of center shaft, improved 3d printability, varioud minor improvements
v0.6 March 26: first version.

Print instructions

NO supports needed. Print 100% solid to avoid creation of internal cavities which may trap liquids.

Carefully inspect the intake airway for loose strands of filament (if any) and remove them with pliers. (The part is carefully designed to limit overhangs to 45° and minimize difficult bridging features in the intake pathway; further improvements ongoing).

Some very thin hairs of filament may still be present which are difficult to observe by the human eye. These can be eliminated with a heat gun, blowing hot air through the intake airway in both directions for a short time (2 seconds). After this step carefully inspect the airway again.

The exhaust airway cannot be inspected entirely due to the hidden structures, but this aspect is less critical as air only flows away from the patient. Still, try to detect and eliminate loose strands of filament (if any) and use a heat gun to eliminate thin hairs.

Sterilization is not recommended for 3d printed parts due to the porous structure. Still, you can try sterilization by heating:
PLA adapters withstand up to 65°.
PETG/CPE at least 80°, CPE+ and exotic materials even higher.

You can try elevated temperatures (e.g. 80° for PLA) as long as the part is not under stress. It will retain its shape and return to normal strength after cooling.

Chemical sterilization: should be possible; experiment
UV sterilization: not recommended as parts are opaque which blocks UV.

Please let me know (groenhuis@gmail.com) if anything is incorrect and should be updated.