40MM NATO (RD40x1/7) to Sundstrom SR Series Filter (SR100/200/900) Adapter

thingiverse

Human: 40MM NATO (RD40x1/7) to Sundstrom SR Series Filter (SR100/200/900) Adapter ============================================================== This prototype design bridges the gap between 40MM NATO (RD40x1/7”) gas mask threads and Sundström SR series respirator filters. The adapter unlocks compatibility with Sundström SR series chemical, combination, and particle filter cartridges, mitigating PPE shortages by expanding cross-compatibility among different manufacturer models. Part Description: ============== 40MM_NATO_TO_SUNDSTROM_FILTER_ADAPTER_BASE_GEN1.stl 40MM_NATO_TO_SUNDSTROM_FILTER_ADAPTER_END_CAP_GEN1.stl 40MM_NATO_TO_SUNDSTROM_FILTER_ADAPTER_MAIN_GEN1.stl 40MM_NATO_TO_SUNDSTROM_TPU_GASKET_GEN1.stl Initial model release features a three-part assembly, including a TPU gasket for users who cannot source O-ring or gasket material from local hardware stores. Disclaimers/Risks: ================ 1.) Use Proper Gaskets The SR series filters have a gasket on the filter side and rely on the silicone sleeve on the respirator side attachment. However, I lack access to SR series filters or respirators, so I designed an adapter to seal against the TPU gasket instead of the OEM gasket on the filter side. A threaded end cap applies compressive force on the angled outer face of the filter cartridge, sealing it against the adapter's TPU gasket. Ensure a positive seal by tightening the provided threaded end cap. 2.) Perform Proper Negative Pressure Test Follow SSPs established by your institution or workplace for further guidance. Don your respirator, adjust straps till taught against your face, ensuring no obstructions around the periphery of the seal. Exhale deeply, cover inhalation ports, and 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 and degrade when exposed to chemicals, heat, and UV/sunlight. This adapter is only a temporarily ad-hoc solution against biological contagions. To improve durability, apply a thin layer of polyurethane clear coat on all exterior surfaces. Dev. Notes: ========== 5/04/2020 - Initial model release. In work, pending support 3D printing community for any fitment and model revisions.