Faceshield Spremberg V1 (for Mini, stackable, default german DIN punch - ISO 838)

Our own development is based on a remix of the original Prusa mask, which is a bit narrower and has an optimized hexagonal cutout. Our own adjustments / improvements are:

• Stackable version without support material
• fits on Prusa Mini print bed ( 18x18cm )
• you can use a strap with a hole as well as a loop (the strap cannot slip out through the corner)
• the holes in the PET film can be made with a standard hole punch. At least standard in germany - 8 cm from hole to hole (DIN - ISO 838). A cutting and hole template is included in the download (SVG and PNG). Or download it as PDF from our page.

We also included the blender-file we used for the customization and stacking. Feel free to remix/use.

Print instructions

• use PETG Filament
• we used a 0.3 mm nozzle on 0.25 – 0.3 mm layer height
• no support
• 30% infill
• 3 layers outer contour (for smoother movement - less infill)

We added the bottom clip of the original prusa design. We don't think it's absolutely necessary for stability. However, it does help if you wear it for a longer period of time, so that you do not lose sight of the bottom edge of the PET-sheet.

Assembly

• print the headband, bottom clip is optional
• if you use the stacked version: Cut the 4 ends of the headband with a cutter for about 4-5cm. Afterwards the headbands can be separated very easily from each other.
• buy a sheet of transparent PET - we found 0.8mm in the garden segment of our local hardware store. A4 foil is also an viable option.
• Make the holes using a standard puncher (german > 8 cm from hole to hole - ISO 838). You have to punch twice. The puncher center marker must be 13.5 cm apart (see instruction in the fourth screenshot or the SVG file).
• Place the foil on the middle 2 knobs of the headband.
• Pull the side parts back carefully one by one so that the film also slides over the buttons on the sides.

Disinfection instructions

If you would like to print the face masks yourself, you should of course make sure that the masks reach the doctors and nursing staff corona-free. The following possibilities exist to ensure this:

• Sterile production / assembly
  During production, gloves and face masks are worn to prevent germs from being spread on the masks. The finished mask is sealed airtight. This variant may be nessesary if the mask is used directly in the hospital environment - ask your hospital what is needed.
• Surface disinfection by qualified personnel
  This is the variant we are using at the moment. We are in contact with a local pharmacist which do the assably and disinfection.
• Heat disinfection
  According to the WHO, the coronavirus, like many other pathogens, is not viable for long at over 60 °C. The finished masks can therefore be "baked" in an oven at 70 °C for about 15 minutes. After that the pathogens should be dead. We have not yet tested this variant. It is also important that the temperature is not too high, otherwise the PET starts to deform. If someone tests this, we would be grateful for feedback.

You may also have a look at prusas official disinfection notes. Ask your local hospital or pharmacist what they need - they will tell you.

Our recommendations beside the print

• The contact to the local pharmacist we have, is "worth its weight in gold". He has the contacts and know how to bring the product to the medical staff, and he is not as buisy as the staff in the hospital.
• We currently just at the beginning (in germany) - thankfully the hospitals are not yet overcrowded. We have many mobile care services for older people and family doctors. That's our main focus at the moment. If we help these people, maybe we can buy the hospitals some more time.