Summary

I wanted to make sure my car was fully equiped in the event of an accident.

Here is a safety hammer, comprising of a blade to cut a seat belt and a hammer end to break windows.
PLEASE NOTE, I HAVE NOT ATTEMPTED TO USE THIS OR TEST IT.

Any other updates you wish to suggest, i can modify and update, or you can derive your own :)

Instructions

Print 'Safety Hammer' for a complete 2 piece build (fits onto reprap).
Print 'Blade', 'Handle' and 'fixing plate' for a 5 piece build (fits onto makerbot platform).

The 5 piece build allows 2 tone colour to be used.

Obtain a standard Stanley Knife Blade '11-921' found in 99E models.
Place blade into trapezium slot.
Using M8 Bolt, grind or file down tip to a point (not shown) and slot into hammer head. Use nuts to either space the bolt, or add weight to the hammer. If using a threaded hex head screw (M8 size), this is not required as they wont fit onto the screw thread.
Bolt both sides together using M5 nuts and bolts. I used 12mm in picture, but minimum for halfs is 16mm. (use glue to hold in blade if not completly held)

For 5 part build...
Using a small metal plate (or printed plate) fix bottom halves of both hammer and blade together, then place nuts bolts and blade and fit the top halves together.

I do recommend buying a safety hammer for real emergancies, but this was something i wanted to offer to the world.

Car Safety Hammer