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

by Ben N on 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, I was fairly easily able to make the PIR communicate to the Arduino and then use that signal to activate something else. I happened to have a servo and laser hooked up to the breadboard with my Lego and hot-glue system, so I tested it all out by making a motion-activated robot. When the PIR would sense movement, the device would turn on the red laser diode and swing the Lego arm it was mounted on back and forth. The effect is sort of an automated cat toy, or a device that startles my wife when she walks into the kitchen at night.

But the proof of concept was good, so I headed over to Fred’s where I have the full-scale mock-up of the STAR TREK DOORS all set up. I mounted the Arduino, breadboard, and relays all to the frame of the door, and the PIR to a light stand over the door frame.

Next, I got out the OTHER air valve I have. I originally ordered two – a three-port valve and a five-port valve. I started off using the five-port valve because it allows for operating an air cylinder under power BOTH directions using just a single switch. However, the cylinder is always under pressure and held in place either fully open or closed. There is no depressurized mode or simple way to open or close the door by hand.

By instead using TWO valves (one to open, one to close) I can still power the doors in both directions, but can also have a manual mode, where neither end of the air cylinder is pressurized. (I could also pressurize both ends at the same time, but I’m not sure how I could do something useful with that, maybe an air brake?) Thinking of safety first, leaving the door depressurized most of the time means that it wouldn’t ever be “locked shut”. In event of a blackout, fire, or other emergency, the door could easily be slid open by hand.

I wired up both air solenoid valves to two of the relays on the four-relay board. That still leaves me a pair of Arduino-controlled relays for other fun, such as activating lights or sounds.

To hook up the air for BOTH valves, I would need an air supply splitter, as well as some way to plug up the spare “OUT” port on the five-port valve, which would mean a trip to the hardware or home improvement store. It turned out to be Fred’s night off, and he was eyeing the Mernards flyer for on-sale plywood, so we headed there for materials.

At the store, we looked at stains, some odd sprinkler parts that also work with air, and then headed to the doors department. The store’s supply of pocket door parts was limited, but we happened to stumble on the “Scratch-n-Dent” door area. A few of these doors were marked as low as $5 each. Some of the fancy security doors, even scratched and dented, were up to $120.

We had originally considered building the STAR TREK DOORS from scratch, but how can you beat five dollars? We found three doors that were hollow-core, with a typical wood-grain finish. One was completely plain, the other two were already drilled out for door knobs and hinges. We got three because that’s how many we could find that more-or-less matched and with three, we can screw one up and still have two to work with! We confirmed the $5 price on the doors with a department lead employee, and then I picked up the air parts while Fred headed to the building materials department to get three sheets of on-sale 1/4″ luan plywood.

Once checked-out and packed in the pickup, we headed back to home base. I was now able to use several adapters to connect the air compressor to both valves. With them wired to the relays and the Arduino running from a borrowed USB adapter, I plugged everything in and did indeed get the correct combination of blinking lights.

I turned on the air compressor and waved my hand in front of the PIR. Sure enough the “Open-the-Door” valve would turn on, pushing the door open, and then a few moments later, turn off, depressurizing the air cylinder. The door would stay open as long as the PIR kept sensing movement. Once it no longer sensed movement, the Arduino code would continue and activate the “Close-the-Door” valve, which would of course close the door, and then a moment later, depressurize the air cylinder.

Wow! This actually worked! As long as the door wasn’t actively opening or closing, I could easily slide it by hand. Using two air valves instead of one gives lots more flexibility in the design of the system. It’s still a wobbly mockup that shakes a bit, but the concept is proving itself well!

Meanwhile, Fred was cleaning up around the actual doorway, including removing the shelf where the right-hand half of the door would need to slide to. We did a mock-up by holding the actual air cylinders over the door. (We have three working air cylinders, a 24″ on the prototype door, and a matched pair of stainless steel cylinders for use on the final project.) While the cylinders have an 18 inch throw, the cylinders total length is about 23″ long. We decided to make the doors that width so that the pair of air cylinders would be able to sit perfectly end to end above the door. It’s a 36″ door opening, so two 18″ doors would be a perfect fit, but have a few more inches hiding in the wall wouldn’t hurt – it would actually make it easier to give more space to attach the air cylinders to the doors, allow for the track, and give more room for weather-stripping.

We decided that on the doors with door-knob-holes, we would cut that side – both to get rid of the hole and save the weight of the heavy particle board right around it. We set the table-saw to 23″ wide and ran the entire length of the door through it.

The cut edge shows how a hollow-core door works – it’s essentially two panels with little more than strips of corrugated cardboard in between. We will have to add a strip of wood along the cut to create a new solid edge. However, it’s not rocket science, and I’ve already learned how to customize hollow-cores while working on my daughter’s Dutch Door.

By then it was about time to call it a night, but it’s pretty exciting to have the air valves working AND cut an actual door to size!

Stay tuned! Subscribe to this blog or my Youtube channel to stay up to date on this project! Click here to see the whole project details and timeline.

One to beam up…. -Ben


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, [...]

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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 [...]

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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 [...]

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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 [...]

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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 [...]

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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 [...]

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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 [...]

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Lighting Smack-Down: 4′ Fluorescent Tubes vs LED

December 12, 2014

Recently, a friend of mine decided to do some garage lighting upgrades, and it inspired me to do the same. While I recently upgraded a number of CFL bulbs to LED bulbs, my shop-light fixtures were still using a combination of T-12 and T-8 four foot fluorescent tubes.
At the hardware store, I saw that they [...]

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