40MM NATO (RD40X1/7) to AOSafety® Threaded Filter Adapter

thingiverse

40MM NATO (RD40X1/7) to AOSafety® Threaded Filter Adapter ================================================== This prototype design for a 40 MM NATO (RD40x1/7), gas mask thread, to AOSafety® thread adapter. The adapter should make RD40x1/7 threaded full face CBRN masks compatible with AOSafety® threaded chemical, combination, and particle cartridges. That is, if anyone still has these canisters around. I was surprised to find folks still had a stock of AOSafety® 8051 bayonet filters, so I assume there may also be threaded canisters versions as well. Part Description: ============= 40MM_TO_AOS_THREADED_ADAPTER_GEN1.stl Single piece construction adapter, for AOSafety® threaded filters that do not require clocking, sized based on threads provided from cwmendel in his AOSafety® to 3M™ bayonet adapter: https://www.thingiverse.com/thing:4205509 40MM_TO_AOS_THREADED_ADAPTER_MONO_GEN1.stp Exported model as .STP as requested for drewdinbitz, to grab dimensions for threads. 40MM_TO_AOS_THREADED_ADAPTER_GEN2.stl Gen. 2 features engraved markings to identify adapter. Engraved at 12-6 O'clock positions, removed 3-9 O'Clock markings as it resulted in an STL file larger than 262 MB upload limit at thingiverse. Disclaimers/Risks: =============== 1.) Use Proper Gaskets Requires gasket/o-ring on the interior side to ensure proper seal between cartridge and interior pocket. Source a gasket or O-ring with a nominal diameter of 72 mm or ~2.83". 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. 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 respirators, adapters and accessories for their institution and workplaces. Dev. Notes: ========= 04/09/2020 - Initial model release. I do not have AOSafety® threaded respirators or filters to check measurements, so please report back in comments for any fitment issues and I’ll release revisions as required. 04/14/2020 - Updated models with engraved markings to identify adapter. Engraved at 12-6 O'clock positions, removed 3-9 O'Clock markings as it resulted in an STL file larger than 262 MB upload limit at thingiverse. Credits: ======= Thanks to cwmendel for releasing an AOSafety® to 3M™ bayonet adapter that allowed me to pull reference AOSafety male side threads for reference, created female threads by offset height of 0.16 mm DIA.