The hard drive platter launcher that [Krux] built has been among my all-time favorite builds and I am so excited that he is showing it off at this year’s Bay Area Maker Faire. At its core the concept is quite simple; dump a large amount of current through a coil all at once, and the magnetic current generated spontaneously repels the aluminum hard drive platter. The devil is in the details and this is where [Krux’s] work really shines.
The clear, 1/2″ acrylic case provides a barrier between the 2,000 Volts raging within. The capacitor bank is built from ten electrolytic caps rated 3,900 µF at 400V and are donated by the Cirque du Soleil show ‘O’ after the use life spec had been passed.
A microwave oven transformer charges the bank. When the desired charge is reached, a solenoid actuates the discharge system to dump the energy through the launch coil. When operated at the highest capacities, the launcher is powerful enough to severely warp the platters. We’re happy to see purpose-built robust controls which include double emergency-stop button, one on the main unit and the other on the controller.
We originally covered the project about a year ago. But there is simply no substitute for seeing this in person! Learn more about Project Hathor (the Egyptian god of joy) by visiting the build pages.
> When operated at the highest capacities, the launcher is powerful enough to severely warp the platters.
What about using this for coin shrinking?
If I recall correctly that is more or less exactly what The Geek Group did.
Probably a overpowered in this case. A single 400V cap should do it if you’re able to trigger fast enough. 400v @ 3900uF ~= 3.1kJ right in the neighborhood of where you need to be for coin shrinking.
You’d need a better enclosure or longer switch wire since the coils turn into grenades.
I think you had a slight math error. Isn’t it 0.31kJ?
Yup! Nice catch.
I misread the formula & thought it was expecting uF
For coin shrinking you probably need a higher voltage to sufficient DI/DT
Very cool. Nice build, too.
Slightly off-topic: do not watch the Cirque du Soleil show ‘O’. Under no circumstances should you pay money for that moronic piece of highly overrated kitsch.
krux did an amazing job on this build, it is a beauty, always fun to watch too.
I bought the capacitors to build a 13kJ version of this, and I’m going to try to launch sheet metal (4000 series aluminum) into a forming die. The project here is 3kJ, which can distort the plates just by launching, so I’m hopeful.
3000 series aluminum, my bad.
How thick is the aluminum? You may be better off using that energy to vaporize a wire under water near the aluminum and force the aluminum into the form. Explosive forming.
I thought about that, but you have to evacuate the other side and clamp the material. I just want to set the plate in the press, charge, fire, and repeat.
Will there be enough momentum in the plate to form it?
No
My 3kJ destruct-o-tron cap bank will wrap a 3.5″ HD platter round a wooden former.
Pics or it didn’t happen
13kJ is plenty from my research, the question is the pulse capability of my capacitors (400V 560uF x 300), and how completely it will conform to the die.
I’ve seen videos of 4kJ presses shearing blanks and using 2kJ to form a sharp flange (I think it was around a 6″ radiused square. This used proper pulse caps in a college research project, so we will see.
Boston Museum Of Science has had one of these since the 60’s/70’s.
Anyone tried to launch spinning discs this way? should stabilize the flight and look really cool…
the platter gets irregularly deformed (both elastically and plastically) upon launch, making spin would just cause all kinds of weird behavior…
Wasn’t Arc Attack doing that for BAMF a few years ago?
Different idea of “launching” than i did. Sharpen those edges, and put some serious spin on them, and you’ll be digging them out of a concrete wall.
What?? That concrete wall behind that screaming man who just dropped his arm onto the floor.
This is the only proper way to send data to the cloud.
Trouble is then keeping it “in the cloud” … :-)
You win the comment section.
It would be interesting to see a mock of this device portrayed to be inserting data into the cloud by firing hard drive platters up. I wonder how many people would actually believe that?
lots
A bunch of BAMFs with their BAMF machine at the BAMF.
Make 2, point them at each other, gets you a large hard drive collider…