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Posted: Thu Jun 03, 2010 9:45 pm
by Technician1002
Find a big tree and shoot a full soda into the trunk. I think you will like the result. It's amazing there is no wet soda spilled after the shot. It becomes a fine mist and drifts off.
Be careful launching heavy projectiles. It places more force on the valve. You don't want a valve to blow up on you. Trust me on that one. I blew a valve out of my ABS cannon when it had a PVC female adapter. I had to change to ABS after the PVC one shattered and the piston launched into my foot. That hurt. Your cannon is PVC. Be careful.
Posted: Fri Jun 04, 2010 5:06 pm
by c11man
well i got the chance to go to my friends house and i can tell you that soda cans do not put too much force on the valve

the annoying part is that i have to find all the peices of can after the shot
also i have no idea how you hip fire cans! cuz when mine shoots the cannon rolls back several feet. also the resulting fog leaves the area smelling of mountain frost witch is quite nice.
Posted: Wed Jun 09, 2010 5:36 am
by Technician1002
c11man wrote:wanna redue the 2inch qdv vs mine with full soda cans? i have a feeling i might win

I have a pop can hang time on youtube. Care to compare?
Listen for the impact for the hang time. 2 inch valve, 3 gallon chamber, 7 foot barrel, 100 PSI.
[youtube]
[/youtube]
As for shooting a tree with a full can at pressure, it is amazing the entire contents of a can quickly become a fine mist that drifts off and leaves the ground dry. A mist of Coke smells nice too.

To hip fire coke cans, I use the large rear of the chamber to lean into the launcher, and then take a step back when it goes off.

Recoil is impressive. Do you have an impacted can photo?
Edit: I took the time to do the Audacity time of the pop can launch. The sound from launch to impact is about 12.6 seconds. The time the impact sound returns will need to be subtracted from the total time. Removing that .3 seconds leaves a hangtime of 12.3 seconds with a full soda.
Posted: Wed Jun 09, 2010 11:40 am
by c11man
very nice, i cannot do hang time because i can aim Plague straight up
the downside of a huge cannon....
also i didnt take pictures of the ruptured cans after impacting a block of wood but the is not nearly as much of the can in one peice as yours. the the walls of the can are shredded and completly removed from the top and bottom of the can
Posted: Wed Jun 09, 2010 12:23 pm
by Technician1002
I shred cans unless I can hit the tree dead on so the can pancakes where the top meets the bottom and provides 2 halves. Shooting through a bush or branches provides shrapnel.
Posted: Wed Jun 09, 2010 12:48 pm
by Lockednloaded
Looks like you both need to agree on firing pressure, barrel size, and uniform ammo to have an official damage comparison. I think you should both try water filled tennis balls, just go pick up a large syringe at a pet store and inject it full of water. Mass your ammo and show your pressure on video and compare your damage afterwards
Posted: Wed Jun 09, 2010 2:29 pm
by c11man
why would we use tennis balls? soda cans dont differ very much from one to the next so its a great ammo for comperosons. and differing barrel lengths is part of the launcher so the diffence in lengh is fine, but pressure i dont generly take it up to 100psi so ill stay at 60 and he can stay at 100 and that should make up somewhat for his much smaller chamber than mine
Posted: Wed Jun 09, 2010 9:02 pm
by mobile chernobyl
Can I play too?
For C11 and my own's safety sake, lets keep our's at or under 100PSI.
I just did a similar test with 10 gallon the other day, but with a full soup can at 490g.
If your going to use a soda can, agree on the brand, type and size as density's can very.
Posted: Wed Jun 09, 2010 11:51 pm
by Technician1002
All are welcome to participate. There is no prize. The largest difference between 12 oz sodas is diet or regular. The ones with lots of sugar weigh a little more. A top limit of 100 PSI is fine. It is all the higher my compressor goes. Can damage against a solid flat object is fine. I have a plate of steel and a 3 foot log, so I can use iron or wood targets.
If anybody else is able to do a hang time video, please post the link to the youtube video here. I have not dumped the sound of mine into audacity yet to time it to the nearest 0.1 seconds, but with a stopwatch I'm getting about 12.5 seconds of hang time.
At 60 PSI with the larger chamber and longer barrel, I'm sure the 3 inch valve might out launch my smaller chamber and smaller valve at 100 PSI.
I have not plugged both into GGDT to see what the prediction is.
Posted: Thu Jun 10, 2010 12:26 am
by spudtyrrant
it's ok i'm here, now its a party

,just got a new pilot for my gun(3/4" piston valve), i will probably do a hang time video too, because i have a feeling that the difference in damage isn't going to be much for the 3" porters as far as soda cans go.
Posted: Thu Jun 10, 2010 10:30 am
by Technician1002
For those with smaller valves, you can play too. I have a tennis ball hang time video on youtube. The 1 inch was giving about 7 seconds of hang time with a tennis ball.
Specs, Marshmallow Cannon
Chamber 1Lb propane bottle
Valve 1 inch QDV
Barrel 7 foot 2.5 inch SDR-26
Pressure ~100 PSI
Hangtime, about 7 seconds.
[youtube][/youtube]
Edit; My official can damage pic is here. It was loud. Anyone want to lend me a high speed camera?
Can damage
Posted: Fri Jun 11, 2010 11:07 am
by Technician1002
Bump, I found the bottom of the can after a search of the lawn. What I found blew me away. The bottom was standing on edge down in the grass which is why it was hard to spot. I picked it up and noticed the edges were very smooth, not sharp. I then noticed why, very evenly all the way around the edge is folded over. This recessed portion of the can flattened some on impact and made a Z fold in the bottom of the can and then tore loose leaving a nice folded over crimped edge.
Posted: Fri Jun 11, 2010 11:10 am
by mobile chernobyl
Why empty cans?
Posted: Fri Jun 11, 2010 11:13 am
by Technician1002
It's the way the thread started. Empties fly at higher velocity and create some interesting damage. This impact was near SOS and very loud. I'll work on some chrono work later. Now I wonder how far I can launch an empty. I've already done some full cans into tree trunks. I have a set of can splat photos.
Posted: Fri Jun 11, 2010 11:16 am
by mobile chernobyl
Cool, works for me lol. Are we trying to shot this into a heavy piece of steel sheet for consistency?