After getting a rocket for my birthday, I saw a video on YouTube where someone attached a video camera and filmed the launch looking directly down the rocket. It was pretty neat because the rocket goes up quite quickly and you can see all the people standing around the launch and then see more of the surroundings. Then the rocket peaks out and you actually see the parachute come out, but it gets a little frantic as the rocket spins a lot on the way down. Still, pretty neat.
In the video, they said it was a gum camera because it was like a stick of gum. I went looking for a gum camera, hoping I could find something cheap (since you could easily break or lose the camera the first time you try it). I found a spy pen on eBay. It looked outwards from the pen, not directly down, and they seemed to go for about $20 shipped. I bid about $13 on a few of them, but never won. I looked around further and found the exact same looking pen at dhgate.com, a sort of Chinese version of Amazon for less than $10. You had to supply your own micro SD card for memory, but it came with a micro USB cable to read the contents. It claimed to be High Definition, but some reviews pointed out that while the resolution was high, really it was just VGA video at twice the size, but not twice the resolution.
It arrived from China on Friday, taking a few weeks to arrive. The pen is kind of big, but a lot of high end pens are big like that. It is shiny black plastic with gold trim. The camera is just above the clip and there are two indicator LED’s on the opposite side of the pen that tell you if the battery is low, the memory is low, the recording status, and the mode you are in. You unscrew the writing end to reveal the memory card slot and USB port. The threads were pretty rough, but they are getting smoother as I take the end off and on and work the threads a little.
I didn’t get a chance to try it out until Saturday because I wanted to use the 512MB card that is in my phone, but I had to move the pictures off the card and into the phone’s memory to make room.
Because there is no real way to interface with it other than the click top and no software to go with it, in order to set the time, you write the current time in a text file on the memory card. The pen then reads the time.txt file the next time it is turned on. A code at the end of the time tells the pen whether to include a date and time stamp on the images.
I played around with it, but it was already dark outside. The camera doesn’t work well in low light, but I was able to get the time set, take pictures, and get video (with sound), and then transfer those over to my computer. For the price, this thing is amazing.
Then today I was going over to Jeb’s to try out the Mr. Beer, celebrate a birthday, and watch the college sports signing festivities. I showed off the spy pen, but then when the time to actually sign the college agreement, there was no pen. So I set the pen to record and that was used the whole time (the battery should be able to record for an hour unless the card runs out of memory first). It probably took 20 minutes of video, taking up maybe 120 MB, so the 512MB card is probably about the right size. Jeb was then able to download the video via a USB cable (I had been taking the card out and reading it directly).
I brought the rocket just in case we would have a chance for a launch, but it started raining, so that will just have to wait until next time. The rocket, with a B size engine in it, is 87 grams, and the pen without the writing end is 20 grams, so I think the rocket will fly. But in order to avoid heavy modifications to the rocket, I was just going to tape the camera to the side, which would put it out of balance. So I don’t know how well it will work. Another idea I thought of was that I could make a pocket on the side and slide the pen loosely into the pocket. Then when the rocket peaks out, the pen would slide out of the pocket. I could wrap the pen in a long bright orange ribbon that would then unfurl and slow the fall and also make it visible. This would avoid a possibly harder landing with the rocket and also maybe give a better view on the way down since it might not spin as much.
Had the pen strapped to a rocket today, but couldn’t get the engine to ignite. I’m not sure what the problem was. Either the launcher, the igniter, or the engine, or how it was all connected. There are only a couple of parts. NASA has thousands of parts to keep straight. We also put together Michael’s rocket. He had C engines, but I put one of my B engines in there which wouldn’t go as high and we could use to gauge the wind. As it turned out we should have just used the C engine because even with a B engine that thing went way high and wound up in a tree. So the good part is we only lost 50% of our rockets, but the bad thing is we lost all of the ones we launched. I think the parachutes may be more of a problem than a solution because they seem much more likely to get the rocket caught in a tree and allow the rocket to catch the wind on the way down. So maybe just as well I didn’t lose the spy pen today.
I have used a few of my spy pens on my RC cars and helicopter. The video was ok, not great at high speeds but for the price of the pens it’s hard to complain.