SpudFiles

Killjoy wrote:Well, no. A rectifier wouldn't convert DC to AC, it can only convert AC to DC because AC alternates. You would have to use something like a power inverter (like the ones you can get for a car). I'm sure there's other ways but I can't think of any right now.

Unless they have some weird circuitry in there, I'm thinking DC may very well work in that thing without converting to AC. AC relays, switches, etc, just have rectifiers built in to convert the soleniod drive power to DC anyway. DC should just shoot straight through the recifier and do it's job.

This is a nice find killjoy. I may pick up a couple to play with. Thanks!

Thanks for the comments guy's, guess all my hard work was worth it.

And that rifle looks vicious, I look forward to seeing it in action. It doesn't use a burst disk valve, does it?

Actually it does use burst disks. The barrel and coupler slide forward, then the burst disk is put in place and the coupler/barrel is slid back and clamped down with the three 1/2 inch bolts. It needs a little modification to make things a little quicker, but I have a ratcheting wrench that allows me to clamp the whole thing down pretty quick.

Unless they have some weird circuitry in there, I'm thinking DC may very well work in that thing without converting to AC. AC relays, switches, etc, just have rectifiers built in to convert the soleniod drive power to DC anyway. DC should just shoot straight through the recifier and do it's job.

This is a nice find killjoy. I may pick up a couple to play with. Thanks!

Ok well that makes since. I knew I was missing something. Well I'm glad I could help you out.

Well I did some testing yesterday, and The Box performed perfectly. It took about 5 minutes to fuel FEAR to a 10x propane/air mix (compressor had a little trouble keeping up), and the ignition system worked like a dream.

I thought FEAR had power with a 4x mix, but with a 10x mix it sounded like a small artillery piece with a concussion to match. Things were knocked of shelves in my garage from it, the entire house shook (according to my parents) and my mom felt the concussion 30 ft away inside the house.

With that said, here's the video

[youtube][/youtube]

Holy Bejeebus - that recoil would be vast from a moderately light cannon that could freely move backwards and if you had a barrel and projectile.

As it appears to weigh a bloody tonne, was dug in, and without projectile... I want to see it with ammo!
Care to try beating your old velocity record?

EDIT: Spelking mistkaes.

KUHFIB!!! Wow! I missed this because I was out of town for fourth.
I'd like to see it with the barrel, ...or maybe not.
Awesome box controller too. 8)

HOLY FUC**NG MOLY!

that is crazy! whan i see how your construction hold the 10x and without DDT i think i will hurry up on UPGBH10x

Man that was intense. The shot was so interesting it's easy lose focus that you're really showing off the control system. Looks like its very effective!!

Care to try beating your old velocity record?

I would, but potatoes don't fit well in a 4" diam barrel. Golfball buck shot on the other hand.....

I should have the barrel built within the next couple weeks and hopefully a recoil absorbing stand within the same time frame. I'll keep ya'll updated.

Nice, I typed in ddt into the search function, and i looked through the 6 pages, and couldnt find what DDT means, could someone please tell me, I have been trying to find out for about an hour.

blind909 wrote:Nice, I typed in ddt into the search function, and i looked through the 6 pages, and couldnt find what DDT means, could someone please tell me, I have been trying to find out for about an hour.

You stole my question

I typed it in on google and it came up with Dichloro-Diphenyl-Trichloroethane, which is a common pesticide.

Deflagration-to-Detonation Transition.
Its when the speed of the flame front of a combustion exceeds the local speed of sound.

Very nice job, Killjoy, and I FEAR when it finally gets a full barrel and projectile.

Killjoy, I just noticed that your meter isolation valve and union are exactly identical to mine.

Good shot there, it looks like your camera didn't really do justice to the sound though. The picture with you sitting on the cannon gives a great idea of how big it is. That's really the first picture you've ever posted of it that gives an idea of the scale.

You're going to be getting some monstrous muzzle energy with it at 10x with a 4" barrel. How long is the barrel you're planning on using, and are you going to leave the porting at 2" or increase it?

Seems like you've got a few steps ahead of me on the hybrid front, I though I was going to catch up there for a few weeks.



DDT = Deflagration to Detonation Transition, in this case.

blind909 wrote:I typed it in on google and it came up with Dichloro-Diphenyl-Trichloroethane, which is a common pesticide.

A quick search of 'DDT' in the Spudwiki came up with this:
http://www.spudfiles.com/spud_wiki/index.php?title=DDT


I'm sensing a strong magnetic field pulling me towards the irony of your signature

Edit: Oh yeah and awesome job Killjoy. You make me proud to belong to the same forum as you do

Hey thanks MrCrowley.

Killjoy, I just noticed that your meter isolation valve and union are exactly identical to mine.

What a coincidence, You wouldn't happen to shop at mcmaster would you? haha.

Good shot there, it looks like your camera didn't really do justice to the sound though. The picture with you sitting on the cannon gives a great idea of how big it is. That's really the first picture you've ever posted of it that gives an idea of the scale.

You're going to be getting some monstrous muzzle energy with it at 10x with a 4" barrel. How long is the barrel you're planning on using, and are you going to leave the porting at 2" or increase it?

Yeah I didn't really realize the scale either till I looked at that picture. Even with me being 6' 5" and 210lbs, that cannon still looks big in comparison.

I'm planning to use a 50 foot long reinforced abs barrel. HGDT says well over a 100,000 ft/lbs of muzzle energy with an eight pound projectile. For now though, the porting will remain at 2". When I get to Stanford though one of my projects will be building a piston valve with 3" porting using the equipment in the machine shops. I just don't have the facilities to do such a thing in my garage.

Even with the 2" porting though, I'm almost positive I'll be able to pierce a 3/4" steel plate I have using a tungsten carbide dart.