Safety enhancements to the PRUSA RC3 Face Shield
Face shields can be used to help protecting personnel against COVID-19 through airborne droplets [CDC 1]. The current shortage and crisis calls for easy-to-manufacture and to use products [CDC 2]. This is a safety enhancement of the Prusa RC3 face shield band [Pr 3], printable in two hours or less, even at 70% infill. It has a safety hook to prevent the transparent plastic sheet from sliding and it also protects the forehead using half of the same type of standard-size sheet. It uses less material, since it does not need the printing of a brow guard or fully covered top, since the top plastic sheet is playing that role.
The STL file can be retrieved from NIH (U.S. Department of Health and Human Services — National Institutes of Health) COVID-19 page:
The original Prusa RC3 can be found here
[Pr 3] https://www.prusaprinters.org/prints/27950/files
. Safety hook preventing the bottom transparent plastic sheet from sliding
. Fully covering the face and the forehead with secured plastic sheets
. Using US-standard three-hole punch size and regular size plastic sheets
. Washable and reusable, and sheets also easy to swap
. Spaced away from the face to accommodate glasses and goggles and prevent fogging
. Large tabs to accommodate many types of elastic straps
. Fast to print and using less material than shields with solid tops or guards — approx. bounding box in mm: 200x147x30
. Can also be 3d-printed in batches of two or three, placed next to each other
. 3d Printed headband (in PLA or other similar materials), rough quality slicing is sufficient, 70% infill with several solid bottom and top layers and minimal support (about 1mm) for the overhang hook, only for its lowest part. The support can be stacked onto the central lower prong and not necessarily on the building plate.
. Elastic band, such as regular sewing buttonhole elastic (for pants), rubber band
. clear plastic letter sized sheets: one for the bottom, and a half, cut lenghtwise for the top, both three-hole punched.
Note: three sheets and two headbands can be used to make two face shields. It is also a good idea to have a few spare sheets, for a quick swap, before needing to thoroughly wash and disinfect everything.
. 3D print the headband and clean the small supports between the front prong and the overhang hook
. Affix the elastic band.
. Cut one transparent sheet in half lengthwise, and three-hole punch it. Also three-hole-punch another sheet. The placement of the holes does not need to be very precise with respect to the edge of the sheet, just roughly in the middle of the length. What matters is only the distance between the holes.
. Affix the bottom, full-sized transparent sheet: first slide it up in between the central lower prong and the overhang hook, then into the prong, and then, slightly pulling, make the side prongs pass through its other holes.
. Affix the top half, at an angle: first the central top-prong through the central hole, and then the two side prongs, one by one, by slightly pulling.
When correctly inserted, the edges of the sheets should be tightly against the front part of the headband.
DISCLAIMER OF 3D Printed PPE
Any face shields, masks, sanitizing objects, or other items delivered are being donated free of charge to assist the recipients in dealing with the emergency situation created by the COVID-19 pandemic. They were manufactured in at home, non-professional environments by volunteers who are non-specialists in the field without prior experience in the manufacture or design of such products, and without reference to any official guidelines, instructions or treatises regarding the manufacture or design. They were also manufactured without official reference to any federal, state or local regulations governing the production or design of such masks.
Any items delivered should be considered as falling under temporary guidelines in response to the COVID-19 public health emergency. They should only be used in an emergency when official alternatives are not available.
These items are being provided as is without any guarantees or warranty. In making this donation, we make no warranties of any kind, either express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, of title, of non-infringement of third party rights or of compliance with federal, state or local regulations. Use of the product by a user is at the user’s risk.
NO REPRESENTATIONS OR WARRANTIES, EITHER EXPRESS OR IMPLIED, OF MERCHANTABILITY, FITNESS FOR A SPECIFIC PURPOSE, NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF OTHERS, COMPLIANCE WITH FEDERAL, STATE OR LOCAL REGULATIONS OR OF ANY OTHER NATURE ARE MADE WITH RESPECT TO THESE PRODUCTS