Making Baseballs Go Supersonic

When professional engineers are giggling like kids, you know something interesting is about to happen. [Destin Sandlin] of [Smarter Every Day], [Jeremy Fielding], and a few other like-minded individuals have built a very impressive air cannon, capable of launching baseballs at supersonic velocities.

Baseball execution. Not for sensitive viewers.

The muzzleloading canon consists of a large pressure chamber and vacuum chamber stuck together, with a plug and baseball separating the two. The barrel forms part of the vacuum chamber, and is sealed off at the muzzle end with plastic tape that ruptures when fired. The firing mechanism runs the entire length of the pressure chamber, exiting out the back where it is held in place by a large pneumatic sear mechanism. When the sear is released, it “pops the cork” between the two chambers, sending high-pressure nitrogen into the vacuum chamber, forcing the ball forward. This causes the plug rod to shoot out the back of the pressure chamber, where it is stopped by a pneumatic piston. The entire thing is permanently mounted on a trailer. A professional-looking control box is used to operate the beast from behind the safety of a steel blast shield.

Be sure to watch the videos after the break with subtitles turned on. The first is the highlights reel, and the second is a very entertaining hour-long behind the scenes look. To the surprise of the builders, they were able to shoot a baseball at Mach 1.38 (1050 mph or 1690 km/h) on the very first try, with only a partially pressurized system and a leaking vacuum chamber. When impacting the thick steel target, the ball disintegrates completely, imprinting its stitches on the target. [Destin] and co recorded the results with his usual high-speed cameras, but also included a Schlieren rig that allowed them to photograph the shock waves and Mach cones generated by the speeding ball. After a few shots, the bolts were stripped out of the pneumatic piston that stops the plug rod, which is no surprise judging by how much the steel frame flexes in that area.

This is a very ambitious project, and we have to agree that it is giggle-worthy. After sorting out the teething issues, we expect to see many more spectacular experiments. [Destin] is well knows for his informative and entertaining videos on everything from Fourier analysis to backwards bicycles. [Jeremy Fielding] builds some impressive tools, and we’ve featured his CNC table saw and DIY dynamometer.

30 thoughts on “Making Baseballs Go Supersonic

  1. Just watched this video. I’m a multi-discipline engineer an this is an insanely magnificent engineering feat using advanced engineering, lots of thought and cool instruments built by a team that are also totally nuts. You gotta support this channel.

    1. It is pretty cool all right. I had my doubts about the nitrogen getting the ball supersonic due to the cooling on expansion. But their final velocity is quite striking. Now I want to know what is holding back my air-rifle!

      It gave me some ideas worth trying. Like heating the chamber and adding some water. Get the temperature enough above boiling at the nitrogen pressure to let the steam condense just before the ball leaves the muzzle. Use enough steam for the heat of vaporization to counteract the heat lost to expansion. The pressure and speed of sound will be held high by the heat provided by condensing steam.

      But honestly, if the goal was supersonic baseballs it would be a lot cheaper and easier to just make a breach for 50 caliber BMG or 20mm canon brass and use some blank loads. If the goal was to do it with compressed gas, then it was wildly successful.

      This isn’t a hack so much as a special effects contraption to get cool video. It takes a team and a sponsor and professionally made equipment. I know the guy who likes selfie video of himself so much (just a personal peeve when the time could be spent showing something) is working on Discovery channel stuff and I’m sure the crew here is angling for a show. And it could be very good except Youtubers do a better job in less time than anything made for TV.

        1. pshaw, I’d copy-edit for free just to not have missing function words. In this case they could take the spare ‘is’ at the end and splice it into the place where ‘are’ is missing in the first sentence, and almost have a clean run of it.
          Perhaps if you clone ‘is’ you get ‘are’?

          1. It’s not free, you pay through the ads, and other people do too. Completely unrelated people are paying the cost of using these “free” services through the businesses baking the cost of advertising into the price of products.

            The trap here is that you have to read the article before you know whether it’s worth paying for, but simply by loading the page you’ve already added to whatever counter that determines how much HaD is getting paid. That being the case, you have every right to complain, and since you’re already paying anyways, you’re entitled to the contents.

            The only leeches here are HaD and whatever middle-man agency that is profiting off the ads. This business model is running not on consenting free exchange, but on tricking people to pay for a service they didn’t ask for, by offering it “free” of cost to some other folk with low standards.

          2. The basic problem with advertising is, that there’s two kinds: one is informing consumers of the availability of products and services, the other is trying to influence consumers and create needs or put down competitors.

            The first type is necessary, the second type is harmful. Likewise, the first type costs almost nothing because consumers will look for the information when they need it – you don’t have to keep pushing it down our throats all the time – while the second type costs a lot of money exactly for the opposite reasons.

            The second type of advertising is the most ubiquitous. Companies plastering their ads on top of each other to say, “Buy from me! No, buy from me!”, and wasting resources since everyone is so swamped with them that they’re being ignored. The only party that wins is the company that sells the advertising space – the rest are simply going through the motions because they have to; otherwise their competitors would gain an edge.

            So, this has created an ecosystem of leeches that provides no advantage to the businesses or the consumers. It is mostly used to “socialize” the cost of low quality websites and services that attract people by trivial entertainment and clickbait, which the viewers would not pay for if they were required to.

      1. Replying here because deeply-nested comments don’t allow it.
        1. Like many on this site, I have a low tolerance for long videos. So a HaD summary of the video is great! Theg say what the video is about, and where some highlights are. We can split hairs about what constitutes “advertising,” (I guess this is meta-advertising!) but summarising someone else’s video/ad saves everyone else some time.
        2. Everyone is bitching about how the comments don’t work. We’re all nerds here, isn’t this a Solved Problem by now? Internet forums were around for years before wordpress. I am partial to the system used on Slashdot, but there must be other comment moderation systems that aren’t based on some weird opaque but still ultimately human powered system like on here.
        3. The above is not supposed to imply that I wish Hackaday was Slashdot :-)

  2. You can get just barely supersonic with a 1.5″x10ft barrel and 4″x5ft well casing pressurized to 220psi using CO2 using no vacuum and a custom designed quick exhaust valve.
    A pykrete ice slug would go clean through a 4×6 at those speeds (or through 3/4″ plywood, a 2×4, your siding, another layer of 1/2″ plywood and then still put a dent in your car)
    Well, it kinda made another plug out the back of the 4×6, but you get the point. :)
    Sadly this was 1999 and documentation of these events is resigned to some random DV tape. I’ll probably find it when I retire.
    A 3″ Fernco rubber end cap, two fitted steel washers, and a bolt/nut make a really reliable/cheap quick exhaust valve capable of way more than you would think. It water tested up to 330 psi with no issues.

      1. I have everything from this still, minus the barrel extension, but the end of the well casing was damaged while moving (the most important part containing the valves and the rather expensive pressure rated 4″ coupler). It would probably still be easier at this point to redo it than to find that tape of it.
        We shot this at some stuffed animals and also have that on tape. It was glorious. A stuffed bunny (it was easter) was basically turned inside out. :)

        There was also a potato chaingun and a shotgun with 6 ‘shells’. The shotgun has survived and I still have it on my wali in WI.
        The chaingun wasn’t really viable as it took my 60 gallon air compressor directly connected to it via a 3/4in air line, and it basically emptied that in less than a minute.

        Someday, when I can do this full time. :)

      1. Helium is the go-to gas for super sonic cannons. Hydrogen atoms are lighter but they air paired up in heavier H2 molecules.

        With air I have manged mach 1.3 ping pong balls but the current record holder is up at mach 2.5 using warmed helium.

  3. The excitement of the development team in the video was contagious. I remember days back when I was an engineer (before career change) I had friends like that… but no collective projects as all-encompassing/large as theirs. Color me impressed, great video and presentation! I was aware of Jeremy’s work, but not the others.

  4. So it’s okay to have a lame baseball go mach1+, but even thinking about building / flying / operating a commercial airliner at supersonic speed is frowned upon ? yeah.. makes perfect sense…. smh

  5. One thing that jumped out to me from the video is that the radial velocity of the pieces seems to be higher than the initial linear velocity of the ball.

    Probably – – Tough to tell without being able to measure things.

    If I think about it enough there’s probably a conservation of momentum argument – the stuff that smooses off to the sides has to compensate for the bit that just stops, but it’s still cool to watch, and a reminder that all kinds of weird and unexpected effects happen at high speed (like shaped charges)

  6. You can hit supersonic without WD-40 using a tin pellet instead of lead. At about 60% the density of lead, the muzzle velocity is about 1300 feet per second, although the energy is calculably lower than the same diameter lead pellet.

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