This is to maybe help some printing them faster. To share what we learned. The mask is at the narrowest point 2.4mm thick that is why prusa recommends to do 3 perimeters (3*.4 = 1.2 and that *2 = 2.4) So with any nozzle you have up to 2x is width that you can relieably print so first establish your max extrusion rate as mike did in a recent video or I outline in my tutorial here https://grabcad.com/martin.pirringer-2/tutorials read the one on Volumetric E and the one on bigger nozzles if you have a choice of nozzles. If you use Prusa Slicer/Slic3r just enter that max Volumetric E in the apropriate fields and you are done. Next calculate the layer height apropriate for your printer with most it should be a multiple of .040mm and keep it between 40-60% of nozzle diameter. Then take a layer width where you can get to 1.2 mm so
.4/.5 nozzle Layerheight .24-.32 (tested on PLA) #perimeters
2 Perimeter width either .6 on all Perimeters or we got one running .48
outside perimeters, .72 inside perimeters. 0.8 on infill
.7/.8 nozzle layer height .4mm (tested HIPS) Perimeter width 1.2 on all. #perimeters 1.
we have no one with a .6 but I might be tempted to run the .8 profile with a .36 layer height
If you do not use prusa slicer take your max Vol E and divide by (perimeter width * layer height) And make sure it does not exceed what your printer can handle. Like if its 60 that your printer can handle then the max speed you set is 60 even if the above equation gives you 80 or 100.
One problem we ran into that as those parts are rather thin sometimes with some material one warped up a little at some point so we added a Brim – the brim is a pain especially on the pegs in the front so I broke out inventor and put “lillipads” at some locations. As you have camfers in the design and with printing with a .8 and 1.2mm layer width a lot of them just had 1 bead making contact with buildplate and on occasion the Nozzle left a little retraction tab and on layer 2 it pulled it off the plate the files are called FSChiron here https://grabcad.com/library/face-shield-11 The files are called FSChiron and the x2,x3,x6 is just how many I combined both print the top and bottom in one shot here is some pics
This is after 2 layers
And this is about 5ish hours later when finished 2
With the print popped off . Those 14mm liily pads are quite easy to remove.
If you want to Help check for details on how at www.vernonrobotics.com