Paintball Chronograph

This slick little chronograph can tell you how fast your paintballs are going, as well as what your firing rate is. In this instructible by [Klash69], you can see how to build one for yourself for less than $40. Chronographs themselves aren’t usually too interesting, but we thing he has done a great job here. You have a nice compact package with a big bright display. All it really needs now is a smooth enclosure. As far as the tech details go, he’s using IR sensors spaced 4 inches apart for detection, at the barrel. We’re not experts, but we think this might not work as well on a gun due to muzzle flash, someone who actually knows should let us know in the comments. The brains are a PIC18F13k50 and you can download a full parts list and schematic on the instructible.

You can see a video of it in use after the break.


20 thoughts on “Paintball Chronograph

  1. Paintball markers (if you’re using compressed air instead of C02) has almost no muzzle flash. The only time I’ve noticed it is during particularly humid days.

    Great project though, I might have to build one for myself.

  2. They are talking about firearms.
    Not only would you have to worry about muzzle flash polluting the IR signal, but muzzle blast would coat the sensors in powder residue or scorch them in short order.
    You would have to set it up similar to commercial firearms chronographs where you fire over it from a few feet away. And given the range the sampling area would need to be wider to ensure you don’t miss the boundaries. Swap in a couple ultrasonic sensor pairs and you’ve probably got what many low to medium end professional chronographs have in them. Maybe add some space between the sensors(say, one foot sensor to sensor) too to make the math a little nicer.

  3. To make a working chronograph for a firemarm there are 2 methods:

    1- a standard one like this but more up front so the powder exaust don’t interfere,comonly named a speed trap.

    2-a thing that look exactly the same aa this one but which use some kind of magnetic sensors and is placed directly on the barrel of the gun,measuring projectile’s speed right before it exit the gun.

  4. For an even more hacked chronograph made from stuff you might already have laying around, you can wire two microphones into a computer, set up two sheets of paper a known distance apart and place a microphone by each sheet.

    Measure the time accurately between the spikes of noise made from each sheet of paper being punched through and you can do the maths to get a fairly accurate speed rating.

  5. Just wondering if it would be possible to try a diferent tact when doing this with a firearm…
    Why not try magnetic resonence???
    An coil on each side of the barrel and as the bullet flys through the centre the out put changes that would give you the time it was in range of the pair of coils and even the edge they were at. Theoretically making finding the speed quite easy. If you could find a way to mesure the signal.
    Vwala no optical gate to get messy (:

  6. Yes, normally you shoot between a pair of sensors to chrono a firearm. However, for paintball guns, this is cheap and effective. Probably pretty accurate as well. Nice work.

    Improvement I’d like to see is another piece of PVC protecting the electronics with the screen and buttons poking out, just to give it a more finished look.

  7. 40 dollars? Not too bad.

    But you can buy handheld field chronographs which are pretty darn accurate for less than that.

    They normally go for about 70-100 dollars for handheld units, but can be found used for 30-40 very easily.

    As far as “muzzle flash” goes, this isn’t an issue even on the coldest of days with Co2 as the propellant. Besides, anyone who is has a need for a chronograph has moved beyond Co2 in the sport anyways. Compressed air at 3-4.5k PSI is pretty much standard now.

  8. $40? Can build this from scrap for under $5 (for the uC) pretty easily. Never thought of building one though.

    Might whip one of these up to chrono my arrows.
    I like the paper punching idea for $0 though!

  9. Dave said “um, the muzzle flash happens after the bullet passes.”

    This is not correct. Once the base of the bullet exists the barrel, the gasses behind it speed past the bullet and in front of it, particularly with boattail bullets. Benchrest shooters use flat base bullets almost exclusively “because” the gasses dont move up around the bullets (because of its flat base as opposed to a bullet) and a gas-less window is left open for the bullet to punch through. In any case any slow motion video of a high-velocity bullet leaving the barrel will show the gasses speeding past it once it is “un-corked” from the barrel

  10. If you want cheap, try using $1 set of earphones from the local dollar store. Attach each earphone to a sheet of paper spaced a know distance apart. Plug the earphones into a stereo digital audio recorder. Fire your projectile so it passes through both sheets of paper. Play your recording back on your pc with an audio file editor. You will be able to see the time delay between the 2 sheets of paper and calculate the velocity.

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