Recent content by BrainEater

Normally, I'd be off chasing powder by now, but the snow in Western Canada sucks right now. So I'm working on this. New nozzle mold. The old Mach 1.25 nozzle is on top of the molding material I use to make these nozzles. ---- -- You can see the back end of the negative rocket nozzle mold...

Thanks for the moderation Unown (WILD) ! It's a science thread, no need for any shenanigan's over anything. ----- While I'm mostly trying to get out to the mountains for some skiing, I am working on this. ------------- I've taken the whole vacuum cannon apart, I'm redoing the C-D nozzle. The...

Heheh Everyone asks about heavier stuff, I always say the same thing: "making something heavy go really fast is easy, it's called a cannon. Want to go faster? thicker barrel more dynamite." Making something really light go fast is hard, and where the art comes in. ----- Space was mentioned...

The Mythbusters ping pong cannon operates exactly like mine, Vacuum+pressure. As far as I know, the Mythbusters hold the "air" record at Mach 1.4 ------------ The equation for the 'exhaust velocity' of a C-D nozzle includes the variable "Universal Gas Constant". Helium has a better gas...

While I don't allow people in front of the muzzle, The ball only goes about 60 feet, all corkscrew. The terminal velocity of a ping pong ball is only 32 M/S. At 428 M/S it slows down fast, and does weird things. Hypersonic ( 1700+ M/S) the ball might just melt after 10 feet of air. Only...

Here's a pic of the Helium test setup. ------ I'm currently reshaping the rocket nozzle. More to come, (after ski season probably) :cool:

Hehe ! I should update this. ------- That's Mach 1.07 (Measured) ----- I've just started playing around with the Helium. Here's Mach 1.25 : Take a look at that red oval. The backdrop is 1/2 inch plywood. The back : ------------- It's worth mentioning that as it turns out, I don't...

Here's a ping pong paddle hit with a 750 MPH ping pong ball : That dimple is 1/8 inch deep. Here's the back : -------- When we get into the supersonic range, there's a nice clean hole through the paddle. The world record of Mach 2.8 puts a hole through 3/4" plywood. (y)

The current world record for this is 976 M/s or Mach 2.8 I've designed this cannon for 100 PSi/100 C helium. Using that gas, the math says exit velocity of 4470 MPH/Mach 5.6/ 2 kilometers per second ! here's a pic of the pressure assembly : The tank is heated, and rated to 150PSi/100C. That...

Happy Friday everyone ! I know some of you know what I'm up to. I want to make a ping pong ball go so fast it melts when it hits air. ----------- For those that don't : In 2013 a paper was published by Purdue university about making a ping pong ball go faster than sound. This paper : (see PDF)...

Wow !! Very cool ! ------ I was just curious. I have a friend in the local university glass blowing dept. , so no worries. ;) --- I've made several lasers from scratch, the one on my list now is a free-electron laser. Another thing I learned from Scientific American !! ;)

Thanks !! I'll dig into that. ----- Re: the argon laser.....Did you actually glassblow the globe fittings on that !!? - I miss that book....mine was so dogeared I started just rolling it up. edit ; I have a few of the original sci-am articles.......the book seems to be way more rare. I made...

Here's the popper. The 3/8" tube assembly with the cylinder goes inside the tank via the 'tee' assembly at the back, it's coaxial..... Tank fill is through the side port with the valve. The trigger is done with the straight through tube...Trigger is tank pressure+50Psi. The pointy bit is a...

I've seen a sig or two here with mention of this book. I'd love to hear stories about projects from this book......I made more than a couple of these. Reprints available? I loved mine, it was a sad day when I lost it.

That would totally work, I considered it. You lose the cool factor of the laser trigger though. ----- Ultimately, it boiled down to price. I got it done for $52 with pneumatics. I got my cylinder today, I'll put another pic up an an hour or so. ----- There is no delay !! One slight defect in...