3M™ Bayonet to Honeywell/Honeywell North® Filter Adapter

thingiverse

3M™ Bayonet to Honeywell/Honeywell North® Filter Adapter ============================================== This prototype design for a 3M™ bayonet to Honeywell/Honeywell North® threaded filter adapter. Created to help cross compatibility of COTS filters with other manufacturer’s respirators, should be compatible with Honeywell/Honeywell North® threaded chemical, combination, and particle cartridges. Part Description: ============= 3M_BAYONET_TO_HONEYWELL_THREAD_ADAPTER_M26X1.57_GEN1.stl Designed based off M26x1.57 Thread for Honeywell/Honeywelll North ® respirators, as reported by erniepike: https://www.thingiverse.com/thing:4269355 3M_BAYONET_TO_HONEYWELL_THREAD_ADAPTER_M27X1.5_GEN1.stl Designed based off M27x1.5 Thread for Honeywell/Honeywelll North ® respirators, as reported by Clownrock95: https://www.thingiverse.com/thing:4252141/files 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, (2) redone chamber from underside OD to wrench flats to reduce printing overhang supports, and (3) added engraved markings on exterior periphery to ID adapter. 3M_BAYONET_TO_HONEYWELL_M26x1.57_ADAPTER_GEN3.stl 3M_BAYONET_TO_HONEYWELL_M27X1.5_ADAPTER_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) chamfered 45 degrees to the wrenching ears.to remove printing overhangs. Disclaimers/Risks: ============== 1.) Designed two version one of M27x1.5 and another M26x157, I do not know if Honeywell/Honeywell North ® respirators have legacy and newer threads to explain discrepancy, or if we are chasing stack up of tolerance from 3D printer, filter female threads, or respirator side male threads. However, the M26x1.57 has empirically been proven to work per erniepike. 2.) Use Proper Gaskets It would appear Honeywell/Honeywell North® filters have gasket on the filter side, but please check to ensure gasket/o-rings properly sealed between cartridge and threads. Source a gasket or O-ring for 27 mm OD or 26.016 mm OD or 1" depending on model that is printed. 3.) 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. 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. 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 Honeywell/Honeywell North ® respirator or filters to check measurements. 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, (2) redone chamber from underside OD to wrench flats to reduce printing overhang supports, and (3) added engraved markings on exterior periphery to ID adapter. 04/28/2020 - 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) chamfered 45 degrees to the wrenching ears.to remove printing overhangs. Credits: ======= Thanks to Clownrock95 for providing the original Honeywell/Honeywelll North ® adapters, original spec of M27x1.5, and special thanks to erniepike's trial and error process to discern better fitment threads.