POP Bottle Exploding Target

by Ben N on November 7, 2015

Two weeks ago, I was at the MOTHER EARTH NEWS FAIR in Kansas. I looked through the vendors for anything unusual and found a “prepper” booth that sold a target system which used compressed air and a soda bottle. It looked like fun, so I bought one.

Of course, I also wondered how hard it would be to build my own…

Essentially, the “MEGA-BOOM” target is a threaded base that’s the same size as a 2-liter bottle cap with a Schrader valve in it. A Schrader is what you think of as a tire valve. They are also available in hardware stores for use with air compressor tanks or water pressure tank valves.

I dug through my recycling bin and pulled out a 2-liter bottle and cap. On my bench, I put the cap in the vise (still on the bottle, so it wouldn’t squish) and drilled a 3/8″ hole in it. I then put a Schrader tank valve through a washer and through the hole in the cap. Next, I removed the cap and threaded on a brass 1/8″ to 1/4″ bushing. This acted as a nut on the back of the cap. Because this valve has pipe thread on it, it needs to go into another pipe fitting – if it had straight threads, it could have a nut.)

With the valve solidly in place built in to the cap, I screwed it on to a bottle, and used the air chuck on my compressor. 120 PSI, here we come!

Next up, it was time to head in to the “Wayback” of my parent’s property, where we could make use of firearms. My Dad broke out the air rifle. It’s a German model, where you pump the gun by breaking the barrel (like a break-action shotgun.)  Breaking the barrel lets you add the pellet, and snapping it shut loads the rifle with compressed air.

We took shots at both the commercially-made and home-made versions of the exploding targets, and both worked great!

2-Liter bottles worked best – they are larger, so easy to hit, and the bigger volume really makes a big bang. Nobody called the cops on us, but it really did make a big bang! On one of our last shots, I added about a quarter cup of flour to the bottle before screwing it on and adding air.

16 oz soda bottles worked well too. Since they are smaller, they are a little harder to hit, and the boom isn’t as big, but you still know you hit it when it goes KA-BOOM!

The commercial target has a heavy metal stand, which could just be set on the ground. Our home-made version didn’t. However, I found that I could just put a valve cap on our target and then stab it right into the ground. It stayed well, not tipping over. After several uses though, the plastic bottle cap did eventually get damaged. Still, it was made in just a few minutes using parts I already had, so not bad at all! We also tried using a garden hose female connection (whose threads are very close to that of a soda bottle) but weren’t able to thread it in far enough to seal up well against the rubber washer.

It was lots of fun blasting targets! There was only a little clean-up at the end, picking up the plastic. The plastic bottles are so light, that there was no concern about “shrapnel”. That said, always wear eye and ear protection around firearms and any exploding targets. Likewise, working with air at 120 PSI has enough danger to it that you want to take common sense precautions.

Till next time, have fun blowing things up!


Bowling Ball vs Solar Panels

by Ben N on May 11, 2015

A while back, I posted a video of a bowling ball smashing into a “Bullet-Proof Coffee Table” that I had built. The idea was that I wanted to test whether or not it really was bullet-proof, only WITHOUT firing guns in my residential neighborhood. I DID have a bowling ball and a ladder, so I decided that a little clever use of gravity might be the right way to go. The impact left an AMAZING looking crack in the glass, and I still get a surprising number of YouTube views of that particular video.

A while back, my friend, Josh, had been doing some work designing a new solar power product – a folding solar panel to recharge USB devices, like smart-phones, tablets, or even GoPro cameras. He asked me if I could lend a hand doing some product photography and testing.

Besides being completely waterproof (which yes, I did test in a river, a frozen lake, and submerged in an aquarium for three days…) he was also going for impact resistance.

So how do you test for impact resistance on a solar panel? Some sort of fancy laboratory test? Nope. Drop a bowling ball on it.

I was also interested in what dropping a bowling ball might do to another solar panel. I happen to own several Harbor Freight solar panels, which I have used for powering my Solar-Powered Power Wheels and charging up my electric riding lawn mower. One of the panels had a defect anyways, so I figured perhaps sacrificing it to the Gods of Gravity might be the best use for it.

I set up my eight-foot step ladder in my driveway and placed the Harbor Freight Panel flat on the pavement directly below it. I climbed the ladder and placed the bowling ball directly above the panel, and then let go. I think the results speak for themselves.

The bowling ball smashed the glass. Surprisingly, very little actual glass came off. There was a relatively small amount of tiny pieces of glass to sweep up, but all of the large pieces of glass DID stay laminated to the panel, even though it was dished to the shape of a bowling ball!

I was curious as to whether or not I could still get any power at all out of the panel, so I tested it out with my multimeter. Open circuit volt testing showed almost twenty volts! Wow, I was sure the panel wouldn’t work at all! Wait a minute…. How many AMPS can it output now? I changed the setting on the multimeter to read current, and short-circuited the panel to itself. The meter read 0.12A. That’s about a tenth of what the panel SHOULD be able to put out. The fact that it could get any current AT ALL to flow is still pretty impressive.

After sweeping up the glass and getting the Harbor Freight panel out of the way, I repeated the test with the Badger Solar Panel, making sure to hold the bowling ball at the same height and center it over the panel. I released the ball and……

The bowling ball basically bounced off the solar panel. It rolled off the driveway and into the grass. I took a look up close at the panel. It was hard to notice right away, but I did see some sort of a mark where the bowling ball hit. It was NOT a crack or dent, but the light definitely did bounce off the panel slightly different in an area about the size of my pinky fingernail. I flipped the panel over and saw that the canvas area right where the bowling ball hit was scuffed up. The impact of the ball drove the entire panel hard enough against the driveway to cut a few strands of the canvas cover.

I plugged my phone in to the Badger panel, and it immediately started charging. The panel was providing its full rated power.

Solar technology is pretty cool stuff! Sometimes it fun to take things apart and see how they work. Other times, trying to destroy things can actually be a useful educational tool as well. (Destructive Testing is actually a really big thing in Consumer Product Testing.) I was shocked that the Harbor Freight panel worked AT ALL after smashing it, and the Badger panel may as well have a force-field around it when it comes to bowling balls. If you want to take a look at that panel, it’s on Kickstarter right now. You can see that HERE.

In the mean time, what’s your experience with solar? Got any stories of your bullet-proof renewable energy system? Let us know!



PIRs and Scratch-n-Dent Doors

February 27, 2015

Progress continues on the STAR TREK DOORS!
Last night, I got a chance to stop on over at Fred’s to work on the doors. I purchased a bag of PIRs (Passive Infrared sensors) from Amazon, and started playing with them, hooking one up to my Arduino Uno. By playing around with a bit of sample code, [...]

Read the full article →

The Girl’s First Robot

February 17, 2015

Recently, I started learning about Arduino – a popular hobbyist microprocessor board. I’d like to use it for home automation and several other projects. In a nut-shell, an Arduino lets you have sensors in, process data, and output signals back to the real world. It’s great for all sorts of things, including robots.
My four-year-old daughter, [...]

Read the full article →

Air Cylinder Position Sensors

February 13, 2015

The latest excitement on the Star Trek Doors project is that I just got two Bimba 18″ air cylinders in the mail from an eBay purchase. The cylinders have a built-in position sensor with a 3-pin M8 connector right on the end.
I was able to look up some information on the cylinders to find out [...]

Read the full article →

Michael Jackson Light-Up Eyes

February 2, 2015

This weekend, I had a chance to start playing with some tutorials and an Arduino Uno, so that I could finally learn about micro controllers, and eventually use those skills for some DIY home automation and LED lighting controls. On a completely different note, my four-year-old girl is now completely obsessed with Michael Jackson, especially [...]

Read the full article →

FLIR One Thermal Camera – First Impressions

January 7, 2015

Today, my FLIR One camera arrived in the mail.
I excitedly tore open the package, but then I slowed down to make sure to take some photos so you all could get my first impressions of this thermal camera designed to work with an Apple iPhone 5 camera.
In the box is the FLIR One camera, the [...]

Read the full article →

Top 5 Places for LED Lighting

January 1, 2015

LED lighting has come a long way, and prices are lower than ever. However, there’s still plenty of people who don’t want to switch over to LED all at once. So, if you only had five LED light bulbs, where would you put them? Here’s my top 5 locations, and some of them might not [...]

Read the full article →

How to be prepared without being a crazy survivalist

December 22, 2014

Recently, I read a thread on a web forum where the poster commented on how well prepared he was, or not, for a temporary black-out.
While the power was briefly out, he took stock of what he did and didn’t have, and in his case, he realized he had no communications during a power outage. That [...]

Read the full article →

Best LED Light Bulb – TCP

December 15, 2014

Recently, I refit my whole house with LED lighting. The next month’s electric bills was one of the lowest ever. Even with central air conditioning and all our modern electronic gadgets, lighting is still a major part of most people’s electric bill and one of the best ways to fix that is to convert to [...]

Read the full article →