Klingon OTF Dagger

thingiverse

Good for cosplay, Halloween, or just fidgeting around. Patterned after the D'k Tahg weapon, this design is a remix of David6722's excellent OTF knife, available on Thingiverse at https://www.thingiverse.com/thing:3619717. The model shown was printed in CC3D Silky Silver PLA and Solutech Black PLA, which gave it a sleek appearance. To see how it operates, check out the video at https://youtu.be/yHsj8J9V-wY. For optimal results, follow the print settings recommended for the original design. A 35% grid infill with no bottom solid layers creates a nice textured appearance on both the upper and lower case halves. To create the left blade, simply mirror the right blade. When assembling the lock spring, be sure to sand the center part so it fits snugly into the lower half of the case. The assembly process is similar to the original design, except for the two secondary blades that engage with the rack-and-pinion teeth on the slider. The case is held together with five 2x5mm metric screws. While gluing the halves together might seem like a convenient option, it's best to use screws since you'll need to open the case eventually to change either the spring or the rubber band. Getting the extend/retract function to work reliably can be a bit tricky. To achieve this, push the thumb slide with one quick motion, all the way to the opposite end stop. Don't hesitate, or the slider will interfere with the lock spring and prevent a positive lock. If it still doesn't work, try bending the lock spring so that the ends have a more aggressive bend towards the blade. To eliminate friction and make the knife work more reliably, rub some paraffin onto the sides and edges of the blade using a candle. Do this also on the secondary blades and their pivot points. You may need to ream out the holes in the blades if they don't rotate easily. If the case binds them, back out the screws a tiny bit. Update: I made some adjustments to the screw holes after experiencing trouble with them being too small for some screw heads. New upper and lower case files are now available.