Projectile photography with an aircanon

[BiOzZ]

i made a system for photographing projectile impacts safely (safe enough) and i thought i would share it with you all
i was originally going to hold off until im finished but with funding problems ill post what i have done now



first is the timing unit ... i chose to use the ever so popular camera axe as its a proven system

i originally purchased the projectile sensor that they sell with the camera axe but i broke it so i made my own
my original plan was to use 2 opamps 2 IR LEDs 2 IR phototransistors and 2 pots but after some playing around and looking at the source code that was ll not really necessary ... i settled just on 2 IR phototransistors, 2 IR LEDs and 4 resistors (i did not have a 500ohm resistor so i used 2 1Ks making the resistor count 4)





the air canon i made wayyy back when i was 15 but i remember it like it was yesterday!
i used a 5 gallon propane tank as the main tank and i pump it with a 2 gallon 150 PSI compressor and send it threw a 3/4" solenoid valve and in to an L joint than i can either put my .75 cal barrel on or bring it down to 1/2 inch for my .50 cal barrel

the safety box (i dont know what else to call it) is made of 1.5" wood reinforced with metal and long 2.5" screws
the glass on the front is 1/4" polycarbonate that is rated for 22 caliber bullet impacts (according to the guy who sold it to me) i bent it my self with a torch (it took FOREVER) and i mount it with bolts and washers
i dont wanna upload a ton of images so i put the canon and the box in one collage



the vents on top prevent the blow out of the screen after 150 PSI have been dumped inside and can force out a great amount of air (for more than can be forced in) while still protecting everyone from flying glass and debris

the spring in the back is very stiff and mainly just help disperse energy and putting more metal between the cardboard and the back to prevent anything from going wrong
the cardboard now consists of a combination of cardboard and foam rubber to help my sharper projectile slow down and i made a small cardbaord box filled with scrap flexible plastic and cardboard to slow it down better (it works)

my primary projectile is this

its made using a half inch welding steel bar and is about 3" long cut using a grinding wheel and a bench press and shined using progressively finer sandpaper
the ridges are on there to reduce rear weight, help break whatever it hits more and help it stop but in the end it just looks freaking cool
i also use wooden slugs and gluesticks

the camera is a nikon D7000 and the flash is an SB-600 for now
i trigger the flash in a dark room at a high camera ISO and a low flash setting to capture the motion quickly





is this hole thing an overkill? ... yes ... was it fun? hell yes XD

so whats left undone?
my highspeed flash unit
but im on my way to finishing it


i need to get some glass for the flash tube and i need a 40kv pulse transformer to trigger it
so far total project cost is $350 ish (not including camera or flash im a photographer i had that already)
so far only $50 for the flash unit

yes i know my english sucks i dont need your feedback on spelling or grammar issues

FUNFACTS!
project was inspired by a HaD posting (the one with the spark flash)
the fastest thing i clocked on it was a gluestick at 918FPS ... thats over 625 miles an hour!

what do you guys think?
ideas?
feedback?
ketch phrases?

EDIT: VIDEO of the canon in action http://www.youtube.com/watch?v=YYs0WZBRtLA 1000FPS

[PhilKll]

Wow thats an awesome project, look like loads of fun, great job!

[MicroGuy]

I was going to build something like this until I found out about the flash needs for it.

Just seemed like it was more trouble and cost than what I had in mind (selling them).

You've done quite well. I'd add some vibration sensors too. You could go all the way and time it from the vibration of the trigger pull, to a chrono to find out how fast the projectile is traveling, then calculate the time to impact and then POW! Take your photo.

That's about what I was planning on, a high speed timer with multiple inputs and outputs. For various sensors and outputs for multiple camera's and flash units.

I'll keep an out here to see how it comes along.

[BiOzZ]

I was going to build something like this until I found out about the flash needs for it.

Just seemed like it was more trouble and cost than what I had in mind (selling them).

You've done quite well. I'd add some vibration sensors too. You could go all the way and time it from the vibration of the trigger pull, to a chrono to find out how fast the projectile is traveling, then calculate the time to impact and then POW! Take your photo.

That's about what I was planning on, a high speed timer with multiple inputs and outputs. For various sensors and outputs for multiple camera's and flash units.

I'll keep an out here to see how it comes along.

Right now that's exactly what I did ... the 2 sensors detect feet per secound than you enter how many inches away you want the flash to go off and it calculates the time needed
It works fairly well for speeds up to 1000fps and as little as an inch

Thanks for the comment I will keep everyone posted on the progress

[nikescar]

Very cool project. I've seen a lot of these types of destruction machines but they always miss a huge part of the fun of destruction... the observation. You have some nice results there.

[BiOzZ]

Very cool project. I've seen a lot of these types of destruction machines but they always miss a huge part of the fun of destruction... the observation. You have some nice results there.

thanks
yeah if i cant see something get destroyed it might as well have not have happened
and i like to photograph the unseen