3M™ Bayonet to MSA® Comfo Classic Threaded Adapter =================================================== This prototype design for a 3M™ bayonet to MSA® Comfo Classic threaded 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 arkurb https://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.
Disclaimers/Risks: =============== 1.) 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.) 3D printing materials are not resistant to many solvents, are water soluble, and degrade when exposed to chemicals. 3D printing this adapter is only a temporarily ad-hoc solution against biological threats. Once supply chain return to normal users should purchase OEM OSHA/NIOSH/EN standard approved adapters and respirator accessories.
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.
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.