FM12 VPU adaptor

thingiverse

This is my attempt to create a VPU adaptor for an Avon FM12 gas mask. The original VPU and adaptor are extremely rare, however I have a very similar VPU, an ESP II made by MSA in the United States, and as the technology is essentially identical it made sense to try to mate them together. The excellent original work by Dingle_Flop (attributed as the source of this Remix) allowed me to simply take their design and add a 'cup' structure to slot over the primary speech module (PSM) on the mask. My original version had clips to hold it onto the mask, however these were the wrong dimensions and likely would have been a weak point, so instead I opted to remove them and simply glue the adaptor to the PSM to make a stronger fit. The cup was also the wrong depth initially and I had to sand it down to get a better fit - I've tried to remedy this in the 3D model, but haven't printed a new version as I managed to get the first one to fit eventually, so if you print this it might not be quite perfect yet. Additionally the VPU requires quite a lot of pressure to get the clips to go into the slots, so I increased the depth slightly on the model so that hopefully future versions will have an easier fit. If anyone uses this model please do let me know how well it fits and if my alterations were any good! I've also made a Reddit post with some additional photos: https://www.reddit.com/r/gasmasks/comments/tq6wkt/fm12_with_3dprinted_adaptor_for_an_msa_esp_ii_vpu/