40MM NATO (RD40x1/7) to Milla EURMASK® (Uno/New) Series Threaded Filter Adapter

This prototype design for a 40MM NATO (RD40x1/7”) gas mask thread to Milla EURMASK® Uno/New threaded series filter adapter. This adapter makes any RD40x1/7 threaded full face CBRN masks compatible with Milla EURMASK® Uno/New threaded series line of chemical, combination, and particle filter cartridges to help mitigate PPE shortages by expanding greater cross compatibility of respirators and filters to other manufacturer models.

Part Description:

40MM_TO_MILLA_EURMASK_THREADED_FILTER_ADAPTER_BASE_GEN1.stl

40MM_NATO_TO_MILLA_EURMASK_THREADED_FILTER_ADAPTER_MAIN_GEN1.stl

40MM_NATO_TO_MILLA_EURMASK_THREADED_FILTER_ADAPTER_GASKET_GEN1.stl

Initial model release, two piece construction for ease of 3D printing, and also provided referenced designed TPU gasket if user cannot source OEM filter gasket.

Disclaimers/Risks:

1.) Ensure to use provided TPU modeled gasket or comparable sized o-ring or hand cut gasket between adapter and filter cartridge.

2.) Perform a proper negative pressure test. Follow SSPs established by your institution or workplace for further guidance. But in general, don your respirator, adjust straps till taught against face, ensuring no obstructions around the periphery of the seal against face either due from hair, facial hair, or otherwise. Exhale deeply. Cover all exhalation ports. (Typically, most full face or half face respirators have two filters, so cover those intake ports with your hands. If your running only one filter, ensure the opposite port has filter cap in place.) Now inhale deeply. The mask should suck tightly against your face without any air leakages. Re-test if adjustments are required at gasket/o-ring interfaces at the adapter.

3.) 3D printing materials are not resistant to many solvents, are water soluble, and degrade when exposed to chemicals. 3D printing this adapter is only a temporarily ad-hoc solution against biological threats. Once supply chain return to normal users should purchase OEM OSHA/NIOSH/EN standard approved adapters and respirator accessories.

Dev. Notes:

5/06/2020 – Initial model release. In work, pending 3D printing community support for any fitment and model revisions.

Credits:

Thanks to drzejkopf for his Milla EURMASK® ETNA to DAR filter adapter design., I extrapolated off the geometry to obtain the opposite respirator/female side mating geometry.
https://www.thingiverse.com/thing:4318660