Discover the very first 3D printable spring airsoft grenade !
When I saw this 80 euros spring grenade for sale on the web I told myself « this is just plastic and spring, it must be printable for 10 euros ! ». So I went to work and here’s the result.

The system is pretty simple but works great ! It consists in a spring chamber and a BB chamber. When you put down the BB chamber, you compress the spring and lock the system with the arm. Put the safetey pin and your grenade is safe. It will explode with a choc, you can adjust the sensibility of the system with the screw that keeps it compressed.
Note that you will have to file the feeding hole for the BBs to fit perfectly in.

What you’ll need to mount your grenade :

• 1 classic AEG spring (not much than 400fps !)
• 4 drill screws of 4mm from 25 to 40 mm long
• 1 drill screw of 4mm from 50 to 80mm long
• 1 screw of 5mm with it’s nut
• 1 safety pin of 2mm

See the video for the mounting tutorial. ;)
Also see the sensibility of the grenade and the spreading test in the video !

https://www.youtube.com/watch?v=ZBRupehvX2Q&feature=youtu.be

Make sur to print the keeper (piece with the 4 holes) with a 100% infill !
Have a good print !

EDIT : added the parts printable separately.
New spreading head for better BB range of dispersion.

ATTENTION : This design was proven to be weak and could be dangerous. I would advise to rather use this design : https://www.thingiverse.com/thing:3741262