Next time you’re in a Nerf gun battle, you better hope you’ve got this absurdly powerful ping pong ball gun. It shoots common celluloid spheres at over 400 meters per second, or Mach 1.2.
This ping pong gun is the work of [Mark French], [Craig Zehrung], and [Jim Stratton] at Purdue University. As you would expect, the gun is powered by compressed air housed in a length of 3 inch schedule 80 PVC pipe. One end of the pressure vessel is sealed with a PVC end cap, while the other is closed off with a doubled up piece of duct tape to contain the pressure.
The interesting bit of the build is a de Laval nozzle between the pressure vessel and the barrel. Just like a rocket engine nozzle, this bit of machined PVC compresses the air coming through the burst duct tape seal and allows it to expand again, propelling the muzzle-loaded ping pong ball at supersonic speeds.
The guys have written a report on their gun, you can grab that over on arxiv.
This is just one example of several pairs of spooky eyes which light up [Vato Supreme’s] bushes this Halloween. The quick and inexpensive build process make it a perfect diy decoration.
Each eye is made up of a ping-pong ball and an LED. But that alone won’t be very spook as the entire ball will glow rather brightly. So he spiced things up a bit by masking off the shape of a pupil and spraying the balls black. The vertical slit seen in white above will glow red like a demon in the night.
The LEDs are driven by an ATtiny85 running the Arduino bootloader. [Vato] found there was plenty of space two write code which fades the eyes in and out using PWM. This happens at random intervals for each of the four pairs he is driving.
We’ve seen a similar project that used oversized LEDs as the eyes. But we really like the idea of using a diffuser like this one. See it in action after the break.
Continue reading “Halloween Props: Spooky eyes light up the bushes”
Beer Pong seems to have been around for some time but it only recently exploded in to a universally known game. But one thing has always bothered us. Who wants to drink the beer into which that grimy little ball has fallen? Leave it to the frat boys at MIT to come up with a solution. Their beer pong table automatically cleans your balls.
Of course the table looks great. It’s outfitted with laser cut felt lettering on the apron, and the top features EL wire highlights. But the two features that really set it apart aren’t hard to spot either. First, there are rain gutters along either side to help catch the spillage. Secondly, that blue ring is actually the input nozzle for the ball cleaner. By pushing the ball through the vinyl sleeve it enters a recirculating liquid cleanser, popping out of the portal on the left a second later. That’s about all the details we have on the system, but you can get a closer look at the inner workings in the clip after the break.
The thing to remember is that these guys NEVER run out of ping-pong balls. They’ve got thousands on hand ever since they built this launcher.
Continue reading “Fancy beer pong table cleans your balls”
[Lou] is at it again, and this time he wrote in to let us know about his automated ping pong table topper. With no good spot to stash an entire extra table [Lou] decided to take a two in one game table approach and fit the top of the ping pong table to his pool table. A ping pong table top is no small thing though and it turns out the best (or maybe coolest) place to store it is above the ceiling! At the flip of a switch a garage door opener pulls away a section of ceiling tiles and a winch motor lowers the table top into place with two cables.
The system works very smoothly using some pretty easy to find parts. [Lou’s] instructional video (embedded after the break) shows the system in action and explains the concepts behind the automation. We aren’t sure how the winch stops lowering the table, but the ceiling section uses a light switch and spring combo as its limit switch. The only thing really missing is the flashing red light, industrial klaxon, and fog machine needed to compliment the screeching nightmare-howl of that winch motor.
Continue reading “Garage door opener used to automatically lower a game table top”
What should you do with your down time between sophomore and junior year at MIT? You better build something awesome. [Christian Reed] didn’t disappoint with his newest creation. He calls it the Ping Pong Mauler and we think that’s an appropriate name. It doesn’t just lunch a ball, it belches forth a relentless barrage.
He certainly has no shortage of ammo. A few garbage bags full of the white orbs number at least 3000 strong, and the plastic drum he’s using as a hopper has room for them all. Jamming is an issue and in the image above you can see him working the agitator with his right hand to prevent a clog. The system is mobile, but the shop vacuum used to propel the balls needs AC power. This means there is a tether that keeps it from roaming too far from home. [Christian] included an air tank in the design but apparently the pressurized air doesn’t do much to help with launch speed. That’s good because pressurized ball guns can be scary.
Check out the video after the break to see the ping pongs fly. We bet they’ll be mowing over some strays out in the yard for at least the rest of this summer.
Continue reading “Ping pong ball barrage”
We had a lot of fun with that title. Of course when you’re talking about launching a thousand ping pong balls into space there’s no end to the puns which can be made. But this is actually a fantastic initiative to get people of all ages excited about science and near-space experiments. [John Powell] offers school children the opportunity to send an experiment into space. He’s Kickstarting the next launch, which is scheduled to take place in September. This way each entrant can fly their project for free, then get the results and a certificate back once the weather-balloon-based hardware is recovered.
There is one size restriction for the program. Each experiment must fit inside of a ping pong ball. But you’ll be surprised what can be accomplished. [John] reports that the most simple, yet interesting project is to place a small marshmallow inside the ball. As it rises through the atmosphere it will grow to fill the entire ball, then be freeze-dried by the the extreme temperatures. Some are not so low-tech. There’s an image of a tiny PCB holding a DS1337 and some sensors. It’s an atmospheric data logger that will provide plenty of information to analyze upon its return.
[via Hacked Gadgets]
[George] started with an 8×8 grid, but just couldn’t help himself from upscaling to this 32×16 pixel ping pong ball display. That’s right, It’s a 512 pixel array of fully addressable RGB LEDs diffused with one ping pong ball each.
We featured the predecessor to this project back in January. That one was an 8×8 display using a Rainbowduino as the controller. [George] took what he learned from that build and expanded upon it. The larger display is modular. Each module starts as an 8×8 grid which connects back to the Arduino using a breakout shield with some Ethernet jacks used as quick connects. The LEDs are driven by 595 shift registers, with transistors which protect the logic chips from the currents being switched.
He had a lot of help soldering all the connections for the display and ended up bringing it to show off at the Manchester mini maker faire. See it in action in the video after the break.
Continue reading “A much larger rainbow board of many ping pongs”