[Bob] wanted to build a pinball-drop-style resetting target that he could use while practicing with his pistol. His first idea was to make the targets sturdy enough for use with 9 mm ammunition, and he planned to use 1/2” thick steel for the targets and 11-gauge steel tubing for the frame. However, the targets weighed 50 pounds together and that was more weight than the pneumatic actuators could lift. He ended up using 1/4” steel and thereby halving weight. The downside was that [Bob] had to switch out the nine for a .22.
Controlling everything is a 555 circuit. When triggered, it opens up a relay for one second, which trips the solenoid valve controlling the pneumatic actuators. Originally he wanted to have switches under each target, and only by dropping all four would the reset circuit be triggered. However, he built a simpler solution: a bulletproof button off to one side–effectively a fifth target–that when triggered resets the targets.
HaD have some pretty good shots in our number but we’d probably end up hitting the pneumatic actuators at least once. [Bob] did add 16-gauge steel sheeting to protect the air lines and wires from bullet splatter, which in his experience is more of a threat than a direct hit.
How about wiring four normally-open limit switches in seroes to be activated when the targets drop.
That way a reset signal is only sent once all four have dropped and closed all the contacts.
Or four normally-closed switches in parallel if you want to cut power to the solenoids once they are all down.
Okay, I have to say it: if it used an AVR or PIC controller, you could change the behavior without having to rewire anything.
Take THAT, all you “I could do that with a 555” types.
Hmm, could of done that with a handful of hydrogen atoms and some time..
Why would you need whole atoms? Surely stripped nuclei work just as well…
I could do it with a handful of quarks and a lot of time.
Why not reduce the target size? Only a bulls-eye counts anyway ;)
Because if you miss, you want to see by how much and in which direction so you can correct. Consistently hitting the same quadrant can be diagnostic for particular errors (flinching, squeezing the trigger too hard, etc.)
Good point. But I think it’s better to use paper targets for calibrating the gun, and yourself to the gun, since it’s cheaper to replace that than with steel plates.
You can reuse steel literally thousands of times, and don’t have to walk out there every ten rounds or so to replace it.
at some point, your time is worth something as well.
Because drop targets are square.
3 or 4 smaller but bof the same weight counter weights would solve it for the 9mm
Why not use a steel frame and replaceable paper targets?
This is simply more fun!
How would you detect hits? Maybe some kind of piezo-microphone in a paper holder, when big spike is detected it means paper was hit?
This is fairly elegant, it could work out pretty good.
get a clamp in there so your piezo is pressed firmly on the paper. and target paper tends to be kinda “stocky” so it should be pretty good at transferring vibration when something punches it.
I think that there’s a big difference between detecting a hit on paper vs. steel: a piece of paper is a low-mass diaphragm, which means it will pick up the acoustic wave from the gunshot, even if the bullet doesn’t come anywhere near the target. I don’t think the acoustic signature of a bullet passing through the paper would be much higher than that, because the bullet doesn’t lose much energy piercing the paper. With a steel plate, on the other hand, transfers vibrations from impact MUCH better than the shock wave through air, for two reasons. First, the plate is massive enough that vibrations through air won’t deflect it much, and second, the impact absorbs most of the kinetic energy of the bullet.
Paper targets don’t go “ping.” Plus, you have to go out to replace them.
Adding a counterweight to the mechanism would probably allow the use of the heavier material.
Switch the plates to 1/4″ thick AR500 steel targets of similar size to support 9MM. 1/4 AR500 can handle up to 45 ACP pistol rounds at short yardage as long as they are not magnum rounds like .357 Mag. Not sure about welding AR500 as it will weaken it, most target vendors sell them with mounting holes and will of course sell you hardened bolts to match.