The Fallout series of games has a variety of ridiculous weapons, not least the Super Sledge — a rocket propelled sledgehammer that looks about as dangerous for the wielder as it does for the opponent. [JAIRUS OF ALL] decided he had to recreate this build in real life, risks be damned.
Unwilling to go the single-use, solid rocket route for his build, [JAIRUS] instead elected to go with an electric ducted fan, supplemented with a propane supply for added flames. It’s not really a rocket of any form, and it’s unlikely the burning propane adds any real thrust, but it does shoot huge flames out the back and it is terrifying. The EDF idle speed can be set by a potentiometer on a servo tester hooked up to a speed controller, while there’s a valve for adjusting propane flow. A switch can then be used to boost the EDF speed higher and increase the propane flow, increasing the violence of the flow out the back of the hammer.
Notably, [JAIRUS] doesn’t actually demonstrate swinging the hammer at anything in particular. We’re kind of glad, as we suspect it might end with a sizable explosion, or burns at the very least. Nonetheless, it would easily be the most terrifying prop weapon at most any Halloween party you took it to. It’s in a similar vein to the fire vortex cannon [JAIRUS] also designed. Video after the break.
The basic idea here is that you feed natural gas (though propane should also work) directly into the engine’s intake by way of a hose attached to the air filter box. While cranking the engine, a valve on the gas line is used to manually adjust the air–fuel mixture until it fires up. It’s an extremely simple hack that, in a pinch, you can pull off with the parts on hand. But as you might expect, that simplicity comes at a cost.
There are a few big problems with this approach, but certainly the major one is that there’s nothing to cut off the flow of gas when the engine stops running. So if the generator stalls or you just forget to close the valve after you shut it down, there’s the potential for a very dangerous situation. Additionally, the manual gas valve will be at odds with a generator that automatically throttles up and down based on load. Though to be fair, there are certainly generators out there that simply run the engine flat-out the whole time.
This one comes to us by well-known purveyor of eyebrow-singing projects [NightHawkInLight], whose propane torch never seems to get a break. The idea here is a large scale version of an apparently popular trick where the “flints” from lighters, which are actually rods of ferrocerium, an aptly named alloy of iron and cerium, are heated to a nearly molten state and dropped onto a hard surface. The molten alloy thence explodes in a shower of sparks, to the mirth and merriment of those in attendance.
[NightHawkInLight]’s version of the trick scales everything up. Rather than lighter flints, he uses ferrocerium rods from firestarters of the type used for camping. The rod is stuffed into a barrel formed from steel brake line which is connected to the output of a PVC air chamber. His ominpresent propane torch is attached in such a way as the flame plays upon the loaded pyrophoric plug, heating it to a molten state before the air is released from the chamber. The massive display of sparks seen in the video below is pretty impressive, but we’re getting tired of gender reveal parties and forest fires. We just hope he had fire extinguishers on hand.
Humans have several primal fascinations and perhaps two of the biggest ones are fire and music. While you can picture some cavemen and cavewomen sitting around a fire beating on sticks for rhythm, we think they’d be impressed if the fire danced along with the music. Through the power of Bluetooth, that’s exactly what [Random Tech DIY’s] new fire pit does.
Technically, this is called a Rubens tube, and while it’s an old technology, the Bluetooth is a certainly a modern touch. As you might expect, most of this project is workshop time, cutting MDF and plastic. The audio system is off-the-shelf and drives some car stereo speakers. The results looked good, and although it always makes us nervous building things that carry propane gas, it seems to work well enough from where we’re sitting.
We had to wonder what things you could change that would affect the display. Changing the number of holes, the diameter of the holes, or the gas pressure, for example, would certainly change how the flames look and react to the sound waves.
Building a barbecue is a common DIY pursuit, and one that comes with a tasty payoff at completion. While many projects focus on charcoal or wood-fired designs, [Andrew] is more of a gas man. Not one to simply buy off the shelf, he designed his own burners from scratch.
This quest wasn’t just unnecessary yak shaving; burners to suit [Andrew]’s desired size and power simply weren’t available. The burner is designed around the Venturi effect, wherein the propane gas is passed through a small orifice, creating a jet and pulling air along with it as it enters the burner tube. This causes the gases to mix, and they can then be ignited when passing through the outlet holes of the burner. Get the orifice and outlet holes sized just right, and you’ll have a burner that produces a hot, blue flame, perfect for efficient cooking.
The orifice was produced with brass plumbing components, and hooked up to a valve rated for use with gas lines. The burner tube itself was created from stainless steel tube, with slots cut to act as outlet holes and with the end crimped and welded shut. A black iron pipe reducer was then used as the air inlet and orifice mount.
The final result is a powerful barbecue burner that is perfectly sized to [Andrew]’s needs. If you’re keen to build your own custom rig, you may find this a useful and cheap way to go versus sourcing parts off the shelf. We’ve seen [Andrew]’s work before, too. Video after the break.
With this build, [Andrew]’s goal was to have a portable oven that didn’t sacrifice on performance. Commercial offerings were easy to lug around, but tend to cool down too much after cooking a pie, leading to lengthy waits for the oven to return to temperature. Not content to wait, [Andrew] specified his build with two custom tube burners to heat the floor, with separate jet burners to heat the cavity. When two jets proved too much, he refined the design to just one to improve efficiency and reduce carbon build up.
The Instructable is a great read, covering both the design of the oven as well as the necessary techniques to cook high-quality Neapolitan pizzas in minutes flat – right down to the selection of flour and proper insertion techniques to avoid sticking. The home pizza enthusiast could learn a lot here, and it’s great to see [Andrew] continue to improve on his earlier designs. Video after the break.
When you hear the name “Tesla”, chances are good that thoughts turn instantly to the company that’s trying to reinvent the motor vehicle and every industry that makes it possible. While we applaud the effort, it’s a shame that they chose to appropriate the surname of a Serbian polymath as their corporate brand, because old [Nikola] did so many interesting things in his time, and deserves to be remembered in his own right.
The swirling blue and green flame front in those experiments make burning propane the perfect working fluid to demonstrate how the Tesla valve works. The video below tells the tale, with high-speed footage showing the turbulence that restricts the reverse flow. The surprise discovery is that in the forward direction, the burning gas actually seems to accelerate as it moves down the valve; hypersonic Tesla plasma cannon, anyone?
We’ve seen Tesla valves before, including one made from a “Shrinky Dink”. That did a pretty good job of visualizing the flow patterns that make the valve work, but there’s a huge showmanship gap between tiny channels filled with colored water and the explosive decomposition of a fuel-air mix. It’s a bit riskier, and standard “don’t try this at home” disclaimers apply, but luckily [NightHawkInLight] still has his eyebrows, so he must be doing something right.