Anvil dropping
This page is about crushing small pieces of electroncis, such as Blackberry devices, by dropping a large steel weight on them. I didn't actually use a real 'anvil' for this, but I figure the term 'anvil dropping', evocative of Bugs Bunny Road Runner cartoons, is a fitting title for the activity.
 Weight fully raised and ready for a drop |
SetupThe original inspiration for this whole madness was this steel cylinder, about 7 cm in diameter, 40 cm long, and 10 Kg in weight that was among the junk in my garage when I bought my house. I figured it might come in handy some day, so I didn't throw it out. After my experiments destroying electronics with an ABS-pipe cannon, I figured the next thing to do was to construct something that would allow me to crush things by dropping this heavy weight on them.
To elevate the weight, I made a hook with a pulley attached to it. This I hooked into a high branch on some overhanging limbs on a tree in my yard. I had to attach several long pieces of wood end to end to reach up to it, and managed to get it high enough that the weight could be raised by 8.5 meters above the ground.
Of course, I also needed some sort of 'anvil' to drop the weight on. For this, I bought a 1" think steel plate, which I rested on several small concrete slab on my lawn. The next step was to invite a bunch of manaical co-workers over for a Barbecue and electronics crushing event. There's just an evil pleasure in crushing small and helpless pieces of obsolete electroncis! |
Originally, I was figuring on building some sort of track for the weight to slide
down on, so that it could precisely hit its target, but that would have limited
the amount of height I can achieve without building something humongous.
Instead, I devised a precise method of
releasing the weight, so that it would drop exactly on target. To accomlish this,
I made an electromagnet out of an old transformer. By interrupting the current
to it, it allowed the weight to be released from the magnet without any sort of
jerking motion that might cause the weight to not drop exactly straight.
Of course, the weight did cause the tree I used to move
a bit. I got around this by first raising the weight just a few centimeters above
its target, aligning the object to be exactly under the weight, and then cranking it
up to height. That way, I was adjusting the aim with the full weight already on
the tree.
At first, I pulled the weight up by pulling on the string by hand. I had to put on
work gloves to minimize the risk of rope burn, but the thin rope I was using didn't
allow me to get a good grip with the gloves. As I figured accidental droppings might
be dangerous, I decided to build a winch for elevating the weight. I used a mandrel
that was meant for a grind stone. I replaced the pulley with a big wooden one,
and the grind-stone end with a hand crank.
This I then attached to a saw horse, and weighed the saw horse
down with a bucket full of old iron parts to keep it from getting lifted in the air.
Experiments
The first victim: A blackberry 950 pager!
Examining the results of the first drop - fascinating
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A coworker cranking up the weight. The big slab of wood servers as a shield to keep my winch from getting dirty when testing with soft fruit and vegetable targets. Unfortunately, the soft vegetable targets didn't give any interesting 'after' results - they were just gone, with lots of sticky bits everywhere!  Soft fruit and VCR combo target |
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Crushed mouse This mouse survived amazingly intact from a drop. The steel weight inside the rubber-coated mouseball, being the hardest thing, ended up absorbing most of the impact. As you can see, it is no longer round. |
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Impaled pressure cooking pot Among our offerings to the gods of gravity, momentum, and steel was this aluminium pressure cooking pot. This drop was with the pot upside down. The weight just went through the bottom, and got stuck in there. Not very often that you see a pot impaled by a steel cylinder! Had to use a hammer to free the cylinder for the next drop! |
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Crushed inexpensive LCD watch We taped the watch to the bottom of the weight and dropped it with the weight, hence the piece of masking tape. The watch was about half the diameter of the crushed mess in the photo before the drop. Takes a licking, but no longer ticking! I bet a TIMEX would't have done much better! |
The result of dropping on a stack of coins
This was a stack of alternating Canadian pennies and Nickels. The pair on the left shows
unmodified currency, the ones on the right were in the stack. Notice how the ones on
the right are a little bigger, and how the nickels have the imprint of the penny and vice
versa!
And this is what the test site looked like after a long series of tests!
The concrete
slabs I put under the steel plate are pulverized. The spot under the steel plate is now
about 2" lower than it was before. There are crushed bits of electronics and sticky bits
of fruit everywhere. Even after cleaning up, I still find the odd capacitor or other
piece of electronics on my lawn. But it was worth it!