40MM NATO (RD40X1/7) to Secura BC Bayonet Filter Adapter

thingiverse

40MM NATO (RD40X1/7) to Secura BC Bayonet Filter Adapter ================================================ This prototype design for a 40 MM NATO (RD40x1/7), gas mask thread, to Secura BC bayonet filter adapter. The adapter is unique from other adapters by allowing users to clock the position of the bayonet/cartridge separate from the RD40x1/7 threads. This adapter makes any RD40x1/7 threaded full face CBRN masks compatible with Secura BC 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_SECURA_BAYONET_ADAPTER_MONO_GEN1.stl Single piece construction adapter, for Secura BC bayonet filters that do not require clocking. 40MM_TO_SECURA_BAYONET_ADAPTER_OUTER_SHELL_LOW_GEN1.stl 40MM_TO_SECURA_BAYONET_ADAPTER_INNER_SHELL_LOW_GEN1.stl Two piece construction, for clocking purposes, and backwards compatible with outer shell of previous Gen 4 40 MM to 3M™ bayonet adapter. Tolerance are more forgiving, lower, to enable ease of 3D printer variation. 40MM_TO_SECURA_BAYONET_ADAPTER_OUTER_SHELL_HIGH_GEN1.stl 40MM_TO_SECURA_BAYONET_ADAPTER_INNER_SHELL_HIGH_GEN1.stl Two piece construction, for clocking purposes, and backwards compatibility with outer shell of Gen 3 40 MM to 3M™ bayonet adapter. Higher tolerance parts requiring proper scaling and calibrated 3D printer. Disclaimers/Risks: ============== 1.) Use Proper Gaskets Requires gasket/o-ring on the interior side to ensure proper seal between cartridge and bayonet. Source a gasket or O-ring with a nominal diameter of 25.2 mm or ~1.0". 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: ========= 04/17/2020 - Initial model release. I do not have any Secura series respirators or filters to check measurements, so please report back in comments for any fitment issues and I’ll release revisions as required. Credits: ====== Thanks to Automagical2 for publishing his Secura series of Polish adapters that allows the 3D printing community to reference regional specific PPE bayonet geometry. United we stand as we combat this global PPE shortage together!