A space grenade inspired by the Space Marine 2 video game. 

Spring loaded action allows the lever to fly off when you pull the pin.
All parts can be printed without supports - even the pull ring.
Print the grenade body in TPU for some extra toughness if you want to throw it about.

Will require a 10mm x 40mm spring in order to have this work. Can be made without the spring.
Springs such as [https://www.amazon.com.au/uxcell-1-2mm-Diameter-Compression-Springs/dp/B076LRJH91](https://www.amazon.com.au/uxcell-1-2mm-Diameter-Compression-Springs/dp/B076LRJH91)
or [https://www.amazon.com/uxcell-Outer-Diameter-Compression-Spring/dp/B076M2CBSX/](https://www.amazon.com/uxcell-Outer-Diameter-Compression-Spring/dp/B076M2CBSX/) should work - anything that is ~10mm should thread into the spring hole without the need for glue, although smaller springs could be held in the hole with E6000 or another flexible adhesive.

 Remember that not everyone will know this is a 3D print, so please make sure you only display it in safe areas or conventions, and not out in public!