I wanted to build a thumper. Not a movie prop replica, but as real of a thumper as I could manage. One that I could actually imagine getting used. This is the story of how I went about that, and what I ended up making.
This entire video was delightful, and I adore the angle of "the most real X that's ever been made." Capping it off with an in-universe, practical instruction guide was perfect.
Agh! This piece of art actually made me shiver! I love your creation. Though I'm a little upset we didn't get to hear how it sounds when put in the sandy ground outdoors!
I really love this, it's such a simple design and completely different to how I pictured them in my head, which as an engineer always fascinates me. I always pictured it as having a heat expansion to create the pressure, hence the candle and something like an escapement from a watch releasing the piston at one or two hertz which satisfied the clockwork style description from the book in my head. As an aside about your comment on the pressure not changing the frequency of the piston in the early test, that's because the frequency is defined by the flow rate in the bypass channels rather than the pressure,
If you neck the flow down to slow the release of CO2 into the piston area, any amount of necking back up underneath the fusible plug will act as a capacitor that can deliver lots of flow, causing a bang when the plug melts. If you cut a hollow spacer to fit inside the plug, you'd replace that large volume of high pressure gas with metal and eliminate the bang. A thinner flow restriction prior to the plug and a better fit between the piston and sleeve would allow the thumper to run for longer, too.
Very neat. Been a Dune fanatic myself for a while. Your idea managed to give me some refinement of how I’d see it. Take your idea, but instead of using the CO2 directly, put it through a fixed orifice restrictor, then have it spin a screw. The screw then can lift a hammer against a spring. At a set point a seer on the hammer section is pushed and released. The spring forcing the hammer section down to strike and thump. The seer resets and up goes the hammer again. The fuel, instant trigger, etc. work just as well as in this video. A screw thread and restrictor give you options to tweak the thump rate to a human stride while probably being a bit more gas efficient, giving you run time. Anyways, still a very neat video and implementation.
A clockwork would have solved the run duration problem. A common escapement could provide a minimum of 20 hours run time. Also clock works are more durable than one might expect. The only real challenge is sealing it against sand while allowing it to function. That said, I could never come close to making the system you came up with. You are to be applauded.
A wonderful design for such an iconic item in everyone's fremkit. A beautifully produced video, too! All you need now is to produce the duagrams and text of the manual for printing directly onto spice-fibre paper.
The worms aren't attracted to the thumping noise. The thumping noise makes them think it is raining and they rise to the surface to avoid drowning. There are birds that thump their wings on the ground together to fool the worms into thinking that it's raining and they rise up to the surface to avoid drowning, only to be eaten.
This was amazing. Really loved the "instructional video" at the end, really brought the whole thing together. I re-read Dune after the latest movie and was really wondering how would the thumper work in real life (other than "it's sci-fi it just does").
Well done, very believable and a nicely functional but also aesthetic result. Almost spooky the way it turned out the piston is visible as it is in the films by serendipitous accident.
12:13 Use the 88g cartridges designed for inflatables. They are larger and could increase your run time. It looks like you are using the 12g size. The cartridges for life rafts and vests also have a threaded neck, which may be helpful for attaching to the thumper.
I'd hollow out the base of the piston and have it hit a poppet valve. Make the bore in the inside of the piston the right depth so that it simultaneously opens the valve and strikes the metal around the valve to make the heavy impact. The open valve releases a spurt of gas into the hollow in the piston, pushing it up and thus closing the valve. If the cylinder is so short the piston hits the upper end, use a buffer spring to slow it down then push it back down to strike the valve for the next cycle. The fusible plug can be places somewhere under the poppet valve with a screen or a wad of steel wool to catch the ejected metal. Another method of safe storage and activation, requiring no disassembly and reassembly would be to have the poppet valve in a movable plug with the piercing needle on its bottom. The plug would have a seal and a way to hold it in place after it's driven down. To drive it down, the piston is held at the top of the cylinder by the buffer spring. Designing a way to hold it up against the spring tension - such that it can be released manually or with heat - would be the tricky bit. Release the piston, it flies downward and by its weight plus spring assist forces the valve block down to where it opens the CO2 cartridge and the block catches into place. In practice a thumper would be a single use device so there would be no need to be able to release the valve block after it's locked down, or to re-set the catch holding the piston up, or to replace the CO2 cartridge. I'd have a threaded top cap on the cylinder and the CO2 cartridge chamber unscrew from the bottom, where the valve block would be pushed out then re-inserted from the top of the cylinder. A simple stepped plug inserted into the cylinder bottom would serve to set the valve block position so its needle would not quite touch the cartridge seal. For sealing the valve block in the cylinder I'd expect Fremen to use a wrap of waxed or greased leather. It only has to work once, briefly. A Earth made prop could get by with an o-ring or two and silicone grease. That's the gist of how I'd make a thumper that's ready to jam into the sand and set off with nothing to take apart and possibly lose in the sand.
Thank you! It was all in central Washington. The basalt columns are at Echo Basin, part of Frenchman Coulee, right off I-90. The sand dunes are a bit farther south along the Columbia, a bit past Beverly, sandwiched between the cliffs and the highway.
Aside from the fact that I hated every dune book after the first, and did not particularly like the ending of the first, I always imagined the thumpers at running at around 180-240 bps.
Very cool and simple. I think you are on the right track there with how a fremen thumper would look/function. I would be interested in making a variant with a small candle holder. You could use longer candles to set your time and once the candle burns down low enough the flame could be moved into position to heat up your valve. Any latch like mentioned in the book could just be a lighter. Very cool idea. Any plans to share your drawings on the thing or sell some units?
Well, I have just spent 20 minutes shouting "CO2 model airplane ENGINE AAAAA!!1111" Tom Stanton has plenty of wids fiddling with them and making his own. Basically - piston has a small protrusion to actuate a ball valve beneath it. Even more basically - piston pokes the ball away from its seat in a ball valve and gets a puff of CO2 in the face. Easy and would run for much longer!
I wonder if a sterling engine would have been an interesting path to take, using the heat of a candle that is explicitly mentioned to drive a motor. or alternatively a flame licker engine ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-zIMsC8a_pG4.html
That, or a Stirling engine. In the desert it could be powered by the sun with a magnifying glass or a concave mirror. By positioning it with respect to the position of the sun, a delayed start by minutes or even hours can be ensured.
Crazy on the comments here about this. It's stupid and useless yet people love it. Some even saying I shed a tear. WOW... Sounds like many forgot to take their meds today.
Holy shit how do you have so few subscribers, this beats the fuck out of AvE this is a machining/”make cool shit" video with _production value,_ *_FUCK me_*
