Wearing the face shield at the mouth. there is a feeling of openness, and it does not get damp. There is no tightening on the head. Since it is attached to the mouth, it is excellent in preventing scattering from the mouth.
The head model used for the installation instructions is a work by lehthanis. "Full Size Human Head Model for resting headsets on" URL: https://www.thingiverse.com/thing:758647 Special thanks to Mr.
File overview msc_006.FCStd (mouth_shield_C-ver. 6th Trial) FreeCAD format file msc_006.stl Mesh format file of frame body only msc_006_pc.stl Model with built-in parts to prevent peeling pin_c_type.FCStd Pin for connection (C type) FreeCAD format file pin_c_type.stl Pin for connecting (C-type) mesh format file pin.zip Pins with different length
A more detailed overview
Emergency declaration has been canceled in Japan. However, I am still required at work to wear a face shield with a mask. The "Inexpensive Face Shield" distributed at the workplace secures the shield in front of the face by wrapping sponge foam on the forehead. This construction of the face shield is very hot and makes the wearer feel uncomfortable. In addition, the rubber used in the mounting feel the tightening very strong depending on the size of the head (the size of my head I feel especially that way so large.) So, I made a brace that is as open as possible and that can be worn without using rubber.
The one I referred to was a shield that was supported by a "chin". However, many "chin" supports have a small shield because their main purpose is to prevent "splashes from the wearer's mouth." It is not possible to protect the eyes and sides of the face from external splashes like this time. And when only the shield was enlarged, the shield shook and was not stable. Therefore, we designed the frame so that it can be mounted stably even with a large shield by enlarging the frame and supporting it under the mouth and the temporomandibular joint. We adopted a method of suspending with a string to prevent it from falling off, but the length of the string is suitable for all head sizes with proper tightening by using a cord stopper. The problem is that the straps are designed to pass over the ears, so some hairstyles can't support the weight of the frame and slip off. You can make a ring with rubber and put it on your ears. I haven't tried.
I used an OHP sheet for the shield part. It was an unwanted item waiting to be thrown away at my workplace. It is a waste product. A5 size was left, so I chose this size, but if you can prepare a large sheet, it is better to use it.
The shield and frame are fixed with pins. By sandwiching the sponge foam and optimizing the length of the pin, you will get just the right friction and you can adjust the inclination of the shield.
If you use a large shield (such as A4 size), it may not have enough friction, but in that case, consider fixing it using the hole at the end of the frame.
It will be more comfortable to wear sponge foam between the frame and face.
For the pin output, it is recommended that the outer wall be increased to output instead of increasing the infill.