« 2022-03-19 Tinkering 2021-07-28 »

Tinkering: 2021-11-06: Face Shield with Glasses

For dusty work like cutting or sanding wood or, in a current project, sanding glass for the next two alarm clocks, I wanted to improve my protective gear. This turned out to become a nice little project on its own, as I made a 3D printed pair of glasses to install into my new face shield.

face shield: with glasses and head So this is my previous protective gear: a good respirator and protective goggles. The respirator is very good, but the goggles are OK for a few minutes only. Firstly, I cannot really wear glasses with them as they start to hurt in a few places where it's just too much uneven pressure on my face. Also, the goggles are not super air-tight with the respirator blocking where it really wants to sit. And then the worst of all, it fogs up within minutes – it is not unheard of that I might sweat when working, and it fogs up even if it feels like I am not sweating.

So this is suboptimal at best.

face shield: with glasses and head I went ahead and got myself this face shield with integrated respirator. Sure, it's quite a bit more expensive, but it is a massive improvement. The first time I tried it, I was delighted by the comfortable fit, the air-tightness, and that it wouldn't fog up at all. The view is very clear (so let's try to not scratch the screen...). The air is channeled from the filter through the space in front of the face into the mouth piece so that there is a constant flow of air in front of the face. This succeeds in preventing any fog-up.

But this face shield does not allow me to wear glasses at all – it becomes leaky, and there is a lot of pressure on the frame of the glasses.

face shield: with glasses and head But I noticed that there is enough space for a frame for glasses inside of the face shield. 3M sells such a frame for this mask, but it might not be available in Germany, and even if I could get it, it is way more expensive than the face shield itself, and it is just some plastic and a wire. Naturally, I opted for more fun: designing this myself and 3D printing it!

This is the first cardboard mockup to learn about the basic geometry: curvature of the shield, position of eyes, and height of the shield for the main anchor where the glasses' frame will be attached to the mask.

face shield: with glasses and head This is the second mockup that is good enough to start 3D modelling.

face shield: with glasses and head And this is the first 3D printed version. It came out fine, but needed a few tweaks, so more prints will follow.

In any case, this was good enough to pack the mask, the printed frame, some calipers, and head over to the optician to scare them. Well, they were not scared, they were actually very helpful in adjusting the geometry of the frame to clamp the lenses better, and in giving hints about improving the position of the glasses with respect to my eyes. In general, they were really happy to do this, and they told me it was a very welcome distraction from the 'usual' orders they have.

face shield: with glasses and head This is the improved version after the discussions with the optician. It is tilted more so it is closer to the face on the bottom – glasses are this way, apparently. It also has an improved groove (which is not shown in the picture) for the lenses, and I made space in the straight mounting base to have a less obstructed field of vision. The new base's shape follows the mouth piece's.

This also adds rings around the protrusions for clamping, i.e., where the bolts go – these protrusions did not print well because of the holes for the bolts: there was a 2x2mm column close to the hole that my printer was not happy about. If too little plastic is extruded, the result is not a clean plastic string, but more of an ugly blob. So the rings stabilise printing by letting the printer extrude more at a time, to get nice strings. These rings were meant to be cut off after printing, but I actually like their look, so they'll stay. Also, the position of the clamping knobs was moved, because they previously scratched my forehead.

face shield: with glasses and head This is the frame inside the mask. I really like the look of the circular shapes.

face shield: with glasses and head In the previous iteration, I had already increased the distance between the lenses so that there is more space for the nose. But it was still pinching, so this is another iteration of the frame, with cut-offs along the nose.

face shield: with glasses and head So then I took the improved frame back to the optician to have some lenses inserted. This is the completed mask, showing the glasses with the lenses.

face shield: with glasses and head And this is the same thing at another angle.

face shield: with glasses and head Haha, yes. Now I can start sanding and make a big mess, and I can still breathe well, and can see the mess I made. Very nice, this is a big improvement!

I really like the look of the circular shapes of the frame.



March 19th, 2022
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