HDD Self-Destruction: Attempt 3
First, a little back-story. Even after building my first two self-destruction rigs I had quite a bit of thermite left over. After a few years the aluminum seemed to be getting pretty oxidized, so I decided to use the rest on one last HDD self destruct rig.
The thermite jet from attempt No. 2 seemed to work pretty well, so built a scaled up version for part 3.
The housing is just 2 chunks of 2x4 with a 1.5in hole drilled through them, enclosed on each end with 3/8in plywood. On the side you can see some of the reinforcing screws I added across the grain.
Here's another shot of the container, the edge of the nozzle is visible at the bottom.
Here's a shot of the combustion chamber's nozzle from underneath.
This is the ignition mixture. As with my other thermite projects I used powder from fireworks as the primary igniter, but this time I cut it 50/50 with some smokeless powder.
The smokeless doesn't do anything to light the thermite (it doesn't burn hot enough), but I was running low on pyrotechnic powder at the time, so I added it in hopes of getting the most out of the pyrotechnic powder I did have.
To set off the primary, I used a short length of ni-chrome wire.
In a pinch I could probably have used a strand of steel or copper wire instead. As long as it glows red-hot when powered, it'll work fine.
Here's the igniter, almost complete.
Rather than ignite the thermite from the bottom as my last igniter did, this one runs through the center of the combustion chamber, igniting all of it much more quickly and increasing the cutting jet's pressure.
Also, this time the igniter is wrapped in 2 ply's from a sheet of tissue paper instead of tape, which had kept version 2 from igniting properly.