40MM NATO (RD40X1/7) to Portwest® Bayonet Filter Adapter

thingiverse

Human: 40MM NATO (RD40X1/7) to Portwest Bayonet Filter Adapter =============================================== This design was originally created as a proof of concept for a 40 MM NATO (RD40x1/7), gas mask thread, adapter to Portwest bayonet filter. Initially, an MSA version was requested by Daramcgrath, and recently confirmed the geometry fitment of bayonet to filter. The design has been updated as a prototype adapter to maximize cross compatibility of full face CBRN RD40x1/7 threaded mask with Portwest line of bayonet filters. Part Description: ================ 40MM_TO_PORTWEST_BAYONET_ADAPTER_PROOF_OF_CONCEPT_ONLY.stl Initial model with rough Portwest bayonet geometry from scaled images alone. 40MM_TO_PORTWEST_BAYONET_ADAPTER_MONO_GEN2.stl Gen. 2 features the following changes: (1) added engraved markings on exterior periphery to ID adapter, and (2) OD of bayonet changed from estimated 31.5 mm to 33.5 mm, bayonet thickness changed from 2.5 mm to 3.0 mm, and on the base/cylindrical extrusion diameter changed from 27 mm to 28 mm. Disclaimers/Risks: ================ 1.) This is a proof of concept only – model in work. [UPDATED - Now Prototyped, Gen. 2 Geometry Works] 2.) Use Proper Gaskets Requires gasket or o-ring on the underside bayonet to ensure proper seal maintained between cartridge and bayonet. 3.) Perform Proper Negative Pressure Test Follow SSPs established by your institution or workplace for further guidance. 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. Now inhale deeply. The mask should suck tightly against your face without any air leakages. 4.) 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. Dev. Notes: ========== 04/09/2020 - Initial model release. In work, pending support and feedback from UK and European 3D printing community for any fitment and model revisions. I do not have Portwest respirators or filters to check measurements, but thought making an 40MM one would gander more attention perhaps, as maybe MSA respirators perhaps are limited overseas. 04/13/2020 - Revised model based on feedback from Daramcgrath. The following changes were made: (1) added engraved markings on exterior periphery to ID adapter, and (2) OD of bayonet changed from estimated 31.5 mm to 33.5 mm, bayonet thickness changed from 2.5 mm to 3.0 mm, and on the base/cylindrical extrusion diameter changed from 27 mm to 28 mm. 04/22/2020 - Received confirmation from Daramcgrath that the bayonet geometry interfaces well with the Portwest filters. Credits: ===== Special thanks to Daramcgrath for taking the time to pull the geometry on the filter side to ensure mating bayonet surfaces are true.