My Automatic Water Gun Project - How I Did It

Okay, so I got this idea the other day. Summer's coming, right? And those manual pump water guns are okay, but my hand gets tired, and honestly, it's just not that cool anymore. I figured, why not make one that shoots automatically? Just press a button, and psssshhhh. Seemed like a fun little project.

First thing, I needed parts. I rummaged through my boxes of old stuff. Found a small electric pump, I think it was from an old desktop water fountain or something. Seemed about the right size. Then I needed power. Dug out a rechargeable battery pack from a defunct RC car. Still held a charge, good enough.

Gathering the Bits and Pieces:

• The small water pump.
• That rechargeable battery pack.
• Some flexible plastic tubing (aquarium air hose worked).
• A simple on/off switch, like a button. Found one in an old electronics kit.
• Wires, of course. Just regular insulated wire.
• A container for the water. I decided to modify an old, cheap water gun shell I had lying around. Gave me a handle and a trigger area already.
• Hot glue gun and some zip ties. Essential stuff.

Putting it Together

Alright, the build. First, I had to get the pump hooked up to the water. I took apart the old water gun body. Found the spot where the original manual pump connected to the water tank part. I managed to jam the intake tube from my electric pump into that hole. Used a generous amount of hot glue to seal it up so water wouldn't leak back out. Then, I attached another piece of tubing to the pump's outlet, running it towards the original nozzle hole at the front of the gun.

Next up, the wiring. This part's usually fiddly but it's simple really. I connected one wire from the battery's positive terminal to one side of the switch. Then another wire from the other side of the switch to the pump's positive connection. Finally, a wire directly from the battery's negative terminal to the pump's negative connection. So, when the switch is pressed, it completes the circuit, and the pump should run. I just twisted the wires together initially and used electrical tape, didn't bother soldering for this quick test.

Now, stuffing it all inside the water gun shell. This took some arranging. The pump fit okay where the old mechanism was. The battery pack was a bit bulky, I had to find a spot for it, ended up securing it near the handle with zip ties and more hot glue. I mounted the switch near the trigger area, drilling a small hole for it. It wasn't super elegant, but it held together.

Testing and Fixing

Filled the tank part with water. Closed it up. Took a deep breath and pressed the button. Whirr! The pump started! But... disappointment. Just a dribble came out the front. Not the cool jet I imagined. Okay, troubleshooting time.

I checked the connections. The tubing wasn't kinked. Maybe the pump wasn't strong enough? Or maybe the nozzle was too wide? I tried narrowing the nozzle opening a bit by partially blocking it with some waterproof tape. Tried again. Better! Got a slightly stronger stream, maybe shooting a few feet.

Then I noticed a small leak near where the pump tube went into the tank. More hot glue! Sealed that up tight. Tested again. Hey, much better! The pressure was building up properly now. It wasn't a super soaker by any means, but it was definitely an automatic stream, shooting maybe 10-15 feet. Good enough for a laugh.

Final Thoughts

So yeah, it works! It's a bit chunky with the battery pack zip-tied on, and the wiring is hidden but probably messy inside. But hey, I press the button, and water shoots out automatically. No more pumping. Took me an afternoon of tinkering. Pretty satisfying to take a bunch of junk parts and make something that actually does what you wanted it to. Now I just gotta wait for a sunny day to properly test it out on someone... I mean, with someone.