Honeywell/Honeywell North® to 40MM NATO (RD40x1/7) Thread Adapter

This prototype design for a Honeywell/Honeywell North® respirator thread to 40MM NATO (RD40x1/7/DIN) gas mask thread, as requested by flipty. Designed to help cross compatibility of commercial off the shelf (COTS) filters with other manufacturer’s respirators, during this PPE shortage, should be compatible with any RD40x1/7 filter canisters.

Part Description:

HONEYWELLNORTH TO_40MM_NATO_ADAPTER__ M27X1.5_GEN1.stl

Female threads designed based off male M27x1.5 thread for Honeywell/Honeywelll North ® respirators, as reported by Clownrock95:
https://www.thingiverse.com/thing:4252141/files

HONEYWELL_NORTH_TO_40MM_NATO_ADAPTER__M26X1.57_GEN1.stl

Female threads designed based off male ~M26x1.57 thread for Honeywell/Honeywelll North ® respirators, as reported by erniepike:
https://www.thingiverse.com/thing:4252141/files

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.) 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.) 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:

04/11/2020 – 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 to check measurements.

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.