1 millimeter – doesn’t sound like much but just 1 mil can make any 2 components or parts very uncooperative, which is what i found after assembling our m5 prototype. m5 is made of essentially 3 main parts for the mask body and a facepiece (more about that later). The 3 parts of the body are front, back and middle(electronoics/wiring) .
Gareth had already made an outstanding design, and we had wanted to use a middle layer to house all the electronics, wires, connectors on one foundation piece, we even painted it blue. The only reason it was painted that color was that Gareth’s cad part was colored in blue. This piece would sit snugly into the rear part.
All 3 parts have magnets to help the user assemble them if they were to wash the mask, something we recommended doing at least once a month.
I had tried just the front and rear parts together and it was magical to see both the rear body pieces gently be guided to come together though the use of the magnets.
I prized apart the 2 pieces (front and back) because they fit perfectly and in went the blue layer piece to see if it fit. all seemed fine until I replaced the rear and now the two outer pieces would not mate correctly leaving an ugly 1 – 2mm gap. i wondered if I had seated the part into its location incorrectly, whatever i did to prod and persuade this middle piece failed.
After some head scratching I felt that heavyweight engineering tactics were required in the form of a Dremel tool with its sander attachment. the blue paint began to disappear and after sometime sanding bits here and there it became apparent that there was some error in the design because i couldn’t even insert the fans into their locations. Hours later between me sanding and Gareth checking and re-checking it appeared that the design app that he was using was not updating and rippling changes through the model as expected. the fan holes were 30mm in one direction and 29mm in another. Not good when a standard part is the same dimensions.
Some quick edits, and updates to the model and a new version was sent to Guthrie. Now, it just so happens that our man Guthrie is a bit of a superstar as far as 3d printers and injection molding is concerned and he was awaiting a new SLA super-fast printer to be delivered out of California. What used to take up to 40-90 mins would now take less than 10- 15mins to print. Gareth sent the new part down to Guthrie and i am going to collect it tomorrow.
1 or 2 more slight iterations to test and prove all the bits work, fit and are made as easily as possible and then we hand off to the mold making phase.