Crush Covid Bracelet (with built-in sanitizer sprayer)

This is an open source 3d printed bracelet made of soft TPU plastic. It has an adjustable wristband that can fit almost all adults and most teens. It has a built-in holder for a 14mm diameter by approximately 55mm tall sanitizer sprayer. (These sprayers are commonly available online, see details below).

Note: If you do not have a 3d printer capable of printing TPU, or you just want to support our projects, we do offer these bracelets on our store. Click here for our store: VORPAL STORE

25% of all proceeds go to health care charities to help fight Covid-19. Our store product includes the sprayer, bracelet, and a pipette to fill the sprayer. We offer three different phrases printed on the band, or you can choose a custom phrase up to 14 characters.

HOW TO USE IT

You can spray your hands in literally two seconds without fumbling through your pockets or purse looking for a little tube of sanitizer. This means you'll be more likely to sanitize after touching things--keeping you safer.

The bracelet is easy to put on, simply trap the spray bottle between your wrist and chest, then shove the strap through the slot from the top side. Try to shove straight down.

Filling the bottle is easy with an eyedropper or pipette. (Our store bracelets include the pipette.) We recommend filling with 70% rubbing alcohol, non-gel hand sanitizer (gel works but not as well), or 151 Everclear grain alcohol (it meets the WHO recommendation of 70% or more alcohol content).

PRINTING WITH TPU

TPU is a very soft, flexible plastic that has a rubber-like feel. It is a great material to print with if you have a hotend that can handle it. It's finicky, but once you get your settings figured out it works very consistently. There are numerous web pages that give tips for printing TPU successfully, and identifying what hotends work best with TPU. But the basics are:

• Print slowly! We print at about 25 mm/s. Printing fast will tend to bind up the soft filament.
• No retraction! At least at first. After you get your printer dialed in, you can try some minimal retraction at a slow retraction speed to reduce stringing.
• Stringing Tips. Play with temperature (as low as possible without clogging) and options like avoiding crossing open areas to reduce stringing. A fast travel speed also helps a bit by breaking up the strings.

If you print this project and find that the band doesn't go into the slot easily enough, you might want to reduce the flow rate on your extrusion. You can also stick a tool (like a hex key) into the slot and wipe it back and forth to break up any threads that might be in there. Finally, you can hit the slot with a flame (very carefully! Keep it moving!) to soften it up, then work a hex key in the slot to stretch it out a bit.

OPEN SOURCE

This project is open source, as all our projects are. It is released under a Creative Commons 4.0 International Attribution-Sharealike-Noncommercial license. You can make these for yourself or friends, but not commercially.

LINKS

• Vorpal Store - If you don't have a printer that can use TPU consider supporting us.
• Project Wiki - More details
• STL Files - Three phrases provided.
• Onshape Source 3D Models - Onshape.com requires a free account to access. You can write the model out in STEP or other formats if you wish to import into another CAD system.