40MM NATO (RD40x1/7) to Moldex® 8000 Series Filter Adapter

This prototype design for a 40MM NATO (RD40x1/7”) gas mask thread to Moldex® 8000 series snap on, radial connector, filter adapter. This adapter makes any RD40x1/7 threaded full face CBRN masks compatible with Moldex® 8000 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_NATO_TO_MOLDEX_RADIAL_FILTER_ADAPTER_BASE_GASKET_GEN1.stl
40MM_NATO_TO_MOLDEX_RADIAL_FILTER_ADAPTER_BASE_GEN1.stl
40MM_NATO_TO_MOLDEX_RADIAL_FILTER_ADAPTER_MAIN_GEN1.stl
40MM_NATO_TO_MOLDEX_RADIAL_FILTER_ADAPTER_THREADED_CAP_LH_GEN1.stl
40MM_NATO_TO_MOLDEX_RADIAL_FILTER_ADAPTER_THREADED_CAP_RH_GEN1.stl
Initial model release.

Disclaimers/Risks:

1.) Use Proper Gaskets and Assembly Notes
Recommended users apply thread locker at the RD40 threaded base part interface with main body. Provided interior gasket at filter pocket for reference or use as template to fabricate own gasket, as it would appear that the Moldex® 8000 filter series has the gasket filter side. Threaded ring cap design required to apply compressive load to ensure seal at base filter.

2.) Perform 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 inhalation 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.) Use At Own Risk – Temporarily Solution Only Until Supply Chain Normalizes
3D printing materials are not resistant to many solvents, are water soluble, and degrade when exposed to chemicals, heat, and UV/sunlight. 3D printing this adapter is only a temporarily ad-hoc solution against biological contagions. In addition to using a properly calibrated 3D printer, due to tolerances of adapters, if possible perform hot nozzle pass on all exterior surfaces, to reduce surface porosity for FDM based methods, otherwise SLS/SLA method preferred. Highly recommended users apply a thin layer of polyurethane clear coat on all exterior surfaces, spray or dip based methods, to help resiliency and durability for repeated sterilization and to reduce fomite transmission in printed infill layers. Once supply chains return to normal, users should purchase OEM OSHA/NIOSH/EN standard approved/conformed respirators, adapters and accessories for their institution and workplaces.

Dev. Notes:

06/03/2020 - Initial model release. In work, pending 3D printing community support for any fitment and model revisions.

Credits:

Thanks to markosaurus for the Moldex® 8000 filter holder design. Used images online and his respirator side geometry, for thickness and depth dimensions to extrapolate the corresponding opposite side attachment geometry.
https://www.thingiverse.com/thing:4231138