3M™ Bayonet to MSA® Comfo Classic Threaded Filter Adapter

thingiverse

3M™ Bayonet to MSA® Comfo Classic Threaded Filter Adapter ================================================= This prototype design for a 3M™ bayonet to MSA® Comfo Classic threaded filter adapter. Created to help cross compatibility of COTS filters with other manufacturer’s respirators, should be compatible with MSA® Comfo Classic series of threaded chemical, combination, and particle cartridges. Part Description: ============== 3M_BAYONET_TO_MSA_COMFO_THEAD_ADAPTER_64.212DIA_THREADS.stl Single piece construction adapter, for MSA® Comfo filters that do not require clocking, sized based on threads provided from JDMac174, 64.212 mm https://www.thingiverse.com/thing:4253780 3M_BAYONET_TO_MSA_COMFO_THEAD_ADAPTER_64DIA_THREADS.stl Single piece construction adapter, for MSA® Comfo filters that do not require clocking, sized based on 64 mm DIA threads provided from arkurbhttps://www.thingiverse.com/thing:4259079 3M_BAYONET_TO_HONEYWELL_THREAD_ADAPTER_M26X1.57_GEN2.stl 3M_BAYONET_TO_HONEYWELL_THREAD_ADAPTER_M27X1.5_GEN2.stl Gen. 2 model features: (1) chamfers added to 3M bayonet to filter mating surfaces to reduce sharp edges that could result in wear on 3M bayonet, and (2) added engraved markings on exterior periphery to ID adapter. 3M_BAYONET_TO_MSA_COMFO_ADAPTER_64DIA_THREADS_GEN3.stl 3M_BAYONET_TO_MSA_COMFO_ADAPTER_64.212DIA_THREADS_GEN3.stl Gen 3 model features the following changes: (1) completely reworked 3M bayonet to filter geometry to ensure proper fitment/compression against OEM gasket in locked position, (2) reduced OAL of adapter and (3) removed gusset supporting printing overhangs. Disclaimers/Risks: ============== 1.) Use Proper Gaskets Requires gasket/o-ring, below bayonet to ensure proper seal between cartridge and bayonet. Source a gasket or O-ring with a nominal outer diameter ranging from 64mm or 2.520" to 64.212 mm or 2.528". 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: ============ 04/10/2020 - Initial model release. In work, pending support and feedback from 3D printing community for any fitment and model revisions. I do not have either MSA® Comfo Classic respirator or filters to check measurements. Oversized female/nut side threads for 0.16 mm clearance from community male models, nominal male/bolt side 64.212 mm (JDMac174) and 64.000 mm (akurb). 04/13/2020 - Revised model based on feedback from 3D printing community. The following changes have been made: (1) chamfers added to 3M bayonet to filter mating surfaces to reduce sharp edges that could result in wear on 3M bayonet, and (2) added engraved markings on exterior periphery to ID adapter. 04/29/2020 - Gen 3 model features the following changes: (1) completely reworked 3M bayonet to filter geometry to ensure proper fitment/compression against OEM gasket in locked position, (2) reduced OAL of adapter and (3) removed gusset supporting printing overhangs. Credits: ======= Thanks to JDMac174 for just releasing a original MSA® Comfo Classic to 3M™ bayonet adapter that allowed me to pull reference MSA® bayonet geometry, and for akurb for remixing it to fit the older respirator.