18650 / 21700 battery flex keychain holster

thingiverse

As I frequently carry with me several 18650 batteries, I created a keychain holster for them to prevent accidental short circuits. Printed in flexible material such as Ninjaflex or Filaflex, this design took less than 10 minutes to complete. A friend later gave me a commercial silicone version of this holster as a gift, but since the original design was straightforward, I decided to make my own. I wasn't sure if my printer could handle the flex height without support, but it did! However, printing with low speed like 15mm/s is essential to avoid warping caused by the hotend. No support is required, and bridging should be okay with minor post-processing. The picture shows a black Ninjaflex build that holds the batteries securely. You can adjust the design by scaling it up in Z-direction for longer batteries or in XY-direction for thicker batteries. The STL file is designed for regular unprotected flat-top batteries but can accommodate other types due to its elasticity. To improve this design, I plan to create a customizable version that allows users to choose different battery types and quantities. We'll see how that goes. UPDATE (25-JAN-2019): A new model has been added for 21700 batteries. UPDATE (02-NOV-2017): A revised model is now available after fixing some flaws earlier. I'm sorry it took so long to update, as I had too many projects on my mind. UPDATE (21-JUL-2017): The insertion hole has been reduced to enhance battery protection. The previous version's picture and STL file have been removed. Once my flex-capable machines are available, I'll post more pictures of the new design in action. Just for fun, I've also uploaded a 2X version. UPDATE (20-JUL-2017): The wall thickness has been increased to make the object more durable and easier to print.