Life Saving Rescue Hammer - Glass Breaker/Seat Belt Cutter

myminifactory

This is a small telescoping, magnetically mounted safety hammer designed for the Fiber Force competition. It's meant to be printed with Carbon-filled Nylon because it gets extremely hot inside my car in Texas when the windows are up, and regular filaments can't handle the heat (145 F +). This filament has superior bonding between layers, ensuring a solid print that won't break down or biodegrade in UV light from the sun. The contest calls for showcasing the high-temperature resistance and high strength of Carbon-filled Nylon. The car environment requires a specific type of material that can withstand daily heating, not break down, and be strong enough to handle the swings of the hammer. These rescue hammers are a good idea, but they often lack practicality in real-world situations. People usually store them in their glove compartment or center console, which has several problems. One issue is that you may not be able to reach it when your seatbelt is locked from an accident, and you're held rigidly against the seat. The glass breaker is meant for emergency situations where the car rolls into water, but if you store it in the center console, everything will fall onto the ceiling when you open it, making it difficult to find in murky water. If your seatbelt is locked as well, the situation becomes even more challenging. A mount can sometimes be too complicated to release in an injured or confused state, and large and heavy mounts often fall off due to adhesive breakdown or dislodgement in accidents. For this reason, I wanted my safety hammer to meet three criteria: (1) Small - easy to place anywhere within reach; (2) Lightweight - won't become dislodged in an accident; (3) Strong enough to withstand repeated blows. I made it small so it can be mounted anywhere, and magnetic-mounted for easy removal but not thrown forward in an accident. The magnet also keeps any rattling down. I chose Carbon-filled Nylon because of its superior bonding between layers, ensuring a solid print that won't break down or biodegrade in UV light from the sun. I made it telescoping to increase the force of your swing, and the Carbon fill is necessary to give the slide the required strength and rigidity to hold up to your swings. Just attach the mount anywhere easily within reach with an adhesive pad, and you won't even notice it there until you truly need it. The non-printed parts are easily sourced online or from craft stores: * A #2 exacto blade for the seatbelt cutter * An M4 set screw to connect the ball bearing to the nut inside the hammer - use threadlock to ensure it never comes undone * A 15mm bearing with an M4 threaded hole, available on eBay or leftover from a delta printer design (that's where mine came from) * You can also use a 10mm bearing with a 4mm hole and an 8mm nut as a spacer for added force and the same spacing as the 15mm bearing * An adhesive pad to attach the mount anywhere within the vehicle close at hand * Four M3x16 nuts and bolts for assembly * A little super glue/epoxy to further cement the blade in place, especially helpful during assembly to keep it in place * Threadlock to keep the 4mm set screw from coming loose Don't use your normal plastics for this - you want to make sure it works when you need it to! PLA won't work because of heat issues inside a car with the windows up. ABS has some layer bonding issues and warping that Nylon doesn't have, so I wouldn't trust my life to a hammer made from ABS. Polycarbonate is probably your best option, but shrinkage makes precision prints difficult and often requires temps above 300C, which can be challenging. PETG would work for the handle but is too flexible to impart the full force of the swing to the glass. Regular Nylon has the same issues as PETG - it's a little too flexible. Assembly is easy: just mate the matching parts, apply some glue to the exacto blade and place it in the inset, and screw everything together. Use a strong adhesive on the mount to attach it anywhere within your car for easy reach in an emergency. This safety hammer was printed using Fiber Force filament.