Have you ever dreamt of becoming a marksman? I can help you! You need a laser pointer, few electronic parts, some trash and 3-4 hours. The target can be stationary and moveable. You can practice as much shooting as you like. Let’s come to the point.
Step 1: Materials and Tools
1 milk carton (for a target)
1 shampoo bottle (for a gun’s barrel)
1 body deodorant enclosure (for a gun’s grip)
color paper (to make a mask and decorate a target)
blister (to shield LEDs )
thread (to hang a target)
double-sided adhesive tape
a laser pointer
4 small bolts with nuts (washers are optional)
For a laser gun – a 2200mF/10V capacitor, a press on/off switch(for a trigger), a 3AA battery holder, a 3V buzzer (with in-built generator), a small switch (to activate a buzzer).
For a target – 1 PNP germanium transistor, 1 NPN transistor (BC547), 1 resistor 1K3/0,25W, 1 speaker 8 Ohm/0,25W, 2 LEDs(red/3mm), 1AA battery holder, a small switch, a phototransistor.
Step 2: Target Schematic
The schematic is a modified RL-oscillator. I added 2 LEDs and a phototransistior. Note: it is important to use LEDs with the lowest working voltage (under 2V). You cannot substitute a germanium transistor with a silicon one.
Step 3: Target's Electronic Work
You needn’t a PCB. Solder transistors, a resistor and wires to the speaker’s lead-outs. When you are done, test the target. As soon as you expose the phototransistor to the light the LEDs will be on and the speaker starts beeping.
Step 4: Mask
I am fond of origami. If you don’t want to be bothered with folding you can draw a picture then cut it out and paste on a piece of cardboard. Punch holes in the eyes to install LEDs. Punch a few holes on the nose just opposite the speaker. Punch holes in the mouth to install a small switch. Punch holes in the bowtie to install a phototransistor.
Step 5: Target's Assembly
Cut out a flap on the side of the milk carton to get an access inside. On the opposite side cut out a hole just a bit smaller than the outer diameter of the speaker. Above this hole, where you suppose cat’s eyes should be, punch holes for the LEDs lead-outs. Punch holes just under the cat’s mouth to install a small switch. Punch holes in the center of the bowtie for the phototransistor’s lead-outs. Fix the speaker with Superglue. Solder wires to the LEDs, the phototransistor and the switch. Fix the battery holder with duct tape on the bottom. Fix pieces of blister over the LEDs with Superglue. Decorate the sides with color paper, secure edges with adhesive tape. Punch holes in the upper part of the milk carton. Take a piece of thread and get it through the holes, tie the ends in a simple knot. The target is ready.
Step 6: Laser Gun Schematic
You needn’t a PCB. The buzzer with a small switch is hooked in parallel with the laser pointer. So if you don’t want a sound effect you can do without them.
Step 7: Gun's Electronic Work
Having done soldering, keep the construction under test. Insert batteries and press the button on the trigger, the laser pointer flashes and the buzzer beeps.
Step 8: Gun's Assembly
Make holes in the shampoo bottle. I made them with a craft knife, hot wire and a hot nail (for bolts). Make holes in the body deodorant’s enclosure. Secure 3AA battery holder inside the shampoo bottle just above the grip(deodorant’s enclosure) with 2 small bolts. Make 3 cuts on the deodorant’s enclosure to mount the trigger switch. The trickiest job is to solder a capacitor and wires to the trigger switch. Make a few turns of duct tape around the laser pointer to hold the button pressed and insert the pointer inside the barrel. Solder the other parts. Secure the grip with two small bolts. The laser gun is ready.
Step 9: Engoy Shooting!
The optimal distance is 4-5m. If you feel boring to shoot at a stationary target, try to hit a moveable one. Hang the target in a proper place and make a few rotations, after releasing the target starts spinning.