6 - point mask head harness / back strap (for British S6 gasmask respirator and others)

The british S6 gasmask was first released back in the 1960's and by now the elastic on the rear straps has completely perished on most of them rendering them unwearable. I designed this head harness to replace the cloth & elastic straps so they can still be used for costumes etc. It may well also fit other masks and please let me know if you try any others. If you have a specific mask in mind that you'd like to use with this then do get in touch with me as I'm happy to tweak the design to work with others. This was designed to be printed on 350mm class printers.

I've designed it with a flexible corrugated structure at the back so that it has plenty of spring and can be printed within a reasonable print volume. I've provided sizes from 2XL down to S based loosely on motorcycle helmet head sizes. Try to pick a size that's a good fit, but you can scale this design in Z to make small adjustments, larger Z size = looser fit, but don't reduce Z too much or the straps will become weak and easily torn.

This design is intended to be printed in 95A TPU, I chose that fairly rigid TPU so that it can be printed on the widest range of printers possible. It should be printable in softer filaments like 90A or 85A but that will result in a looser fit so you might need to go down a size or two if you do that. PEBA might be an even better choice but I don't have any handy to test. Support should not be used with this design and it might benefit from a flame-polish after printing to avoid it scraping sharp edges over your ears.  This is printable with nozzle sizes of 0.6mm or smaller but may not work on 0.8mm and larger. If your slicer has a "precise Z height" option then use it to improve strength of the corrugated section.