3M™ Bayonet to 40MM NATO (RD40x1/7) Adapter

thingiverse

3M Bayonet to 40MM NATO (RD40x1/7) Adapter This prototype design for a 3M bayonet to 40MM NATO (RD40x1/7/DIN) gas mask thread is designed to ensure proper seal between the cartridge and threads. It features chamfers on the 3M bayonet to filter mating surfaces, reducing sharp edges that could result in wear on the 3M bayonet. Part Description: The adapter is available in three versions: Gen1, Gen2, and Gen3. The initial model release requires an o-ring or gasket inside the female side 40MM NATO threads to ensure proper seal. The Gen2 version features chamfers added to the 3M bayonet to filter mating surfaces, redone chamber from underside OD to wrench flats, and engraved markings on the exterior periphery to ID the adapter. The Gen3 version features reworked 3M bayonet to filter mating surfaces to ensure positive engagement against OEM 3M gasket durometer, and redone chamber from underside OD to wrench flats to completely eliminate printing overhang supports on wrenching ears. Disclaimers/Risks: 1. Use Proper Gaskets: Requires a 40 mm OD gasket or o-ring on the underside bayonet to ensure proper seal maintained between cartridge and threads. 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. 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. Dev. Notes: 04/11/2020 - Initial model release. In work, pending 3D printing community support for any fitment and model revisions. 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. 04/26/2020 - After getting my hands on a physical prototype, thanks to jlwatchman, updated model to with 3rd revision by removing all overhang support on underside of wrenching ears, changed workflow of female side geometry, with greater thicknesses to ensure positive engagement with OEM 3M gasket durometer, recessed pocket thickness increased past ramp, and ramp height increased to ensure proper compression against gasket.