COVID-19 Lightweight 3D Printable Face Shield by V4HE

Last crawled date: 4 years, 1 month ago

UPDATE (03/04/2020): The models have been modified to lower the profile of the arms by 4mm, saving around 0.4m of filament.
This simple face shield combines advantages from numerous innovative designs that I've seen recently. There are four versions of the frame; narrow and wide brow each with either 3 or 4 locating pins. The pins are spaced for standard A4 3-hole or 4-hole punches. Retaining arms on either side of the frame ensure that the visor stays firmly attached, and the 297mm (arc length) visor provides protection all the way to the temples. An elastic band is all that is needed for a strap, and self-adhesive foam provides comfort.
The shield has been designed to provide a close fit to a European head shape (intermediate cephalic index), optimized for 55-57cm head circumference (average female and male respectively, UK). By design, the maximum head circumference that can be accomodated without foam padding is 60cm. With an extra layer of foam, a head circumference as small as 53cm may be accomodated.
The narrow brow frame can be printed in under 3 hours, does not require any supports and uses 9.5m of 1.75mm filament. The wide brow frame takes a little longer and requires 10.75m of filament. The single-piece print fits on a 200mm x 200mm print bed (actual size approx. 184mm x 177mm). Comfort is provided via draught excluder foam, which is readily available online and is very cheap. The visor is made from a single piece of A3 acetate, although the frame itself can hold thicker material if you would rather use something different, such as PET. The design is flat so it should be relatively straightforward to CNC or laser cut, with only the pins needing to be either modified or post-processed.WARNING: No claims are made about the accuracy and/or safety of this device. Make and/or use at your own risk.Required Hardware
A3 clear acetate sheet, 240 - 300 micron.
9mmx5mm self-adhesive foam weather strip
Elastic band (elastic cord, woven elastic and rubber strip would also work well)
2-hole punch (3-hole or 4-hole preferred for speed and accuracy).
A4 paper, 1 piece (required if you have a 2-hole punch)
3-pin or 4-pin 3d printed frame, depending on the type of punch you have
Scissors, tape measure and pencil. Additionally scalpel, steel rule and cutting boardBuild Guidance (please also refer to the pictures provided)
Measure and cut the self-adhesive foam. 190mm is sufficient to cover the brow, 280mm will wrap around the frame to give a snug fit for small heads. The wide design has an 18mm lip so can take 2 rows of foam. I found 190mm of foam sufficient with the wide design. My head is 55cm.
Sit the 3d printed frame on a clean, flat surface such as a cutting board or table. Peel the backing off the foam and stick it to the interior curved edge. Use the flat surface to help line up the foam with the frame. Omit this step if you have a big head, rinse and repeat if you've got a small head. One layer of foam worked fine for me.
IF YOU HAVE A 3-HOLE or 4-HOLE PUNCH: Set the guide to A4, and punch the narrow side of the A3 acetate (which is A4 size). You now have your holes.
IF YOU HAVE A 2-HOLE PUNCH: Fold the piece of A4 paper in half to find the centre and draw a line on the crease to make it visible. Measure and draw a line 80mm in each direction from the centre. Line the length of the A4 paper along the width of the A3 acetate, with the lines on the outer edge. The static should hold the paper in place. You need to punch twice, lining the centre of the punch with each outer line. You now have your 4 holes.
You now need to trim the visor to length. I personally found 250mm to be adequate. Measure 250mm down from the side with the holes. Use a pair of scissors, or a scalpel to cut it to size. It may also be a good idea to put a radius on the bottom corners to prevent them snagging on things. I used a CD as a template (r = 60mm).
Attach the visor to the frame. The hollow part of the frame should not be visible from the outside. start by placing the edge of the acetate into one of the retaining arms. Now work around the frame from one side to the other, pushing the pins into the holes one at a time. I found it easier to slot the edge of the acetate into the other retaining arm before locating the final pin.
Add the strap to the back.