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Post by Cybermortis on Nov 11, 2012 16:53:55 GMT
Past experience with similar devices tells me that yes the fur will burn up. But unless soaked in a flammable liquid it won’t stay on fire long, and is usually out well before the tennis ball hits the ground. With the air cannon it will definitely act as wadding. With the powder charge it will do the same until it’s burned off. Use injectable insulation foam to give it some rigidity, or an epoxy to get it strength and weight, they will be more durable, therefore reusable compared to ping pong balls. Especially with a powder charge The problem would be the required bore size - which would require a thicker barrel, a larger cannon and therefore a MUCH heaver lump of ice to try and cart around even for an air cannon. |
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Post by trakmec on Nov 11, 2012 17:13:28 GMT
that's true, are there any other smaller constantly sized projectiles that would not require much work?
What about using an alumium rod "bullet"? They could pick the desired diameter. It could be easily made just cut to length, and should be more durable than ping pong balls.
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Post by The Urban Mythbuster on Nov 11, 2012 17:21:43 GMT
Molded epoxy spheres? I'm just trying to think of materials that would allow for easy molding/shaping, but would still have the mass to be a projectile.
If a smaller bore were tested, same diameter as a gun barrel for example, would musket balls be a viable option? Or, would they be too heavy? Then again, could just increase the air pressure to make the musket ball eject. But, doing so might overstress the ice and create a failure.
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Post by Cybermortis on Nov 11, 2012 17:26:09 GMT
The advantage of ping-pong balls is that they can buy hundreds of them for next to nothing, and is they are filling them with foam they should be able to make more than enough suitable ammunition in an hour or so. (In fact they could probably make all they need on the test day while they are waiting for everything else to be set up).
They can also vary the mass of the balls by injecting different fillings, allowing them to use low mass projectiles when seeing if the cannon is capable of withstanding the pressures involved. Then ramp things up with heavier fillings/projectiles to see what sort of damage such a cannon could cause.
You could use other objects sure, but it adds cost, time and a degree of pointless complexity to the overall build for what is a largely irrelevant part of the myth. You also have to factor in the probability of some types of projectile damaging the barrel during loading, and the ease with which you could see the shot in flight - painting a ping-pong ball bright colours isn't a problem, and indeed would take next to no time.
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Post by The Urban Mythbuster on Nov 11, 2012 17:56:31 GMT
It would appear that we have almost completely fleshed out an experiment here. We have considered barrel types & sizes, projectile types & sizes, and method of propulsion (powder, air). If the MBs or some agent for the MBs is checking these boards, this is definitely at the point of going to proof of concept (small scale) testing and then full scale.
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bioLarzen
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Post by bioLarzen on Nov 12, 2012 2:45:38 GMT
that's true, are there any other smaller constantly sized projectiles that would not require much work? What about using an alumium rod "bullet"? They could pick the desired diameter. It could be easily made just cut to length, and should be more durable than ping pong balls. Sounds like an idea to me. bio |
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Post by blazerrose on Nov 12, 2012 4:26:54 GMT
I am so intrigued by this concept, and I'm so glad this one got brought over from the other boards. This would be a great one for the Build Team to take on, since there are several components that need to be made and several permutations to test.
*waves hand mystically* MythBuster researchers, this is the one you seek.
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bioLarzen
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Post by bioLarzen on Nov 12, 2012 15:19:33 GMT
I am so intrigued by this concept, and I'm so glad this one got brought over from the other boards. This would be a great one for the Build Team to take on, since there are several components that need to be made and several permutations to test. *waves hand mystically* MythBuster researchers, this is the one you seek. Haha, I never knew this idea was brought up in the Discovery forums - it just occured to me as I was reading the glass cannon thread here  bio |
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Post by Cybermortis on Nov 12, 2012 15:29:04 GMT
I am so intrigued by this concept, and I'm so glad this one got brought over from the other boards. This would be a great one for the Build Team to take on, since there are several components that need to be made and several permutations to test. *waves hand mystically* MythBuster researchers, this is the one you seek. Haha, I never knew this idea was brought up in the Discovery forums - it just occured to me as I was reading the glass cannon thread here bio It was posted two or three times on Disco, but seems to have been one of those good ideas that got missed or misplaced. And Blazer - What makes you think the researchers haven't already spotted this? As a Disco-posted idea they can use the basic idea as is. |
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Post by OziRiS on Nov 12, 2012 21:04:12 GMT
Just a thought here...
As a basic concept, a cannon is pretty much just a pipe from which you can propel a projectile, right?
If we can agree on that, then it could be made pretty easily if they're going to alaska to do this.
Find an iceberg/glacier and drill a hole in the side of it: Barrel.
Pack it with explosives and a projectile that fits the diameter of the hole and hey presto: Cannon.
If you do it low enough on the iceberg/glacier, the ice should already be pretty tightly packed and with X tonnes of ice around it, it shouldn't (easily) come apart when fired.
Granted, you can't move it around to aim it, but if you can propel a projectile from it, it's basically a cannon.
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bioLarzen
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Post by bioLarzen on Nov 13, 2012 2:58:49 GMT
Just a thought here... As a basic concept, a cannon is pretty much just a pipe from which you can propel a projectile, right? If we can agree on that, then it could be made pretty easily if they're going to alaska to do this. Find an iceberg/glacier and drill a hole in the side of it: Barrel. Pack it with explosives and a projectile that fits the diameter of the hole and hey presto: Cannon. If you do it low enough on the iceberg/glacier, the ice should already be pretty tightly packed and with X tonnes of ice around it, it shouldn't (easily) come apart when fired. Granted, you can't move it around to aim it, but if you can propel a projectile from it, it's basically a cannon. If we only want to have an ice cannon that can be fired then it's absolutely OK. However, if we want a cannon that has some of the other basic features of a cannon - like (controlled) mobility or the ability to be aimed - then it's much trickier with your setup bio |
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Post by The Urban Mythbuster on Nov 13, 2012 3:05:32 GMT
Not sure that would still be working off the original premise of the myth. The idea was to make an ice cannon, drilling a hole in a glacier or some other large ice mass would only prove that you could shoot a projectile from a hole in large ice mass.
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Post by freegan on Nov 13, 2012 3:13:45 GMT
Not sure that would still be working off the original premise of the myth. The idea was to make an ice cannon, drilling a hole in a glacier or some other large ice mass would only prove that you could shoot a projectile from a hole in large ice mass. How do you propose they place the fuse and ignite it? Drilling a hole in a glacier doesn't provide for a fuse-port. |
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Post by chriso on Nov 13, 2012 4:24:25 GMT
Not sure that would still be working off the original premise of the myth. The idea was to make an ice cannon, drilling a hole in a glacier or some other large ice mass would only prove that you could shoot a projectile from a hole in large ice mass. How do you propose they place the fuse and ignite it? Drilling a hole in a glacier doesn't provide for a fuse-port. Electrically? They would probably do that anyhow for safety. |
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Post by OziRiS on Nov 13, 2012 12:08:35 GMT
Just a thought here... As a basic concept, a cannon is pretty much just a pipe from which you can propel a projectile, right? If we can agree on that, then it could be made pretty easily if they're going to alaska to do this. Find an iceberg/glacier and drill a hole in the side of it: Barrel. Pack it with explosives and a projectile that fits the diameter of the hole and hey presto: Cannon. If you do it low enough on the iceberg/glacier, the ice should already be pretty tightly packed and with X tonnes of ice around it, it shouldn't (easily) come apart when fired. Granted, you can't move it around to aim it, but if you can propel a projectile from it, it's basically a cannon. If we only want to have an ice cannon that can be fired then it's absolutely OK. However, if we want a cannon that has some of the other basic features of a cannon - like (controlled) mobility or the ability to be aimed - then it's much trickier with your setup bio I know, it's not the conventional way you think of a cannon But how about doing this for some of the small scale testing? They could test charge and projectile types this way without having to do a lot of over the top prep work and, as an added bonus, they get to see what type of damage they can expect to the ice, giving them an idea of how thick their cannon should be. And yes, I was thinking electronic ignition too. A fuse would melt away some of the ice as it's burning down and potentially create a hole large enough that a significant amount of the gasses from the explosion could escape, leaving less gas in the actual cannon to propel the projectile. |
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bioLarzen
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Post by bioLarzen on Nov 13, 2012 17:50:29 GMT
I know, it's not the conventional way you think of a cannon But how about doing this for some of the small scale testing? They could test charge and projectile types this way without having to do a lot of over the top prep work and, as an added bonus, they get to see what type of damage they can expect to the ice, giving them an idea of how thick their cannon should be. And yes, I was thinking electronic ignition too. A fuse would melt away some of the ice as it's burning down and potentially create a hole large enough that a significant amount of the gasses from the explosion could escape, leaving less gas in the actual cannon to propel the projectile. Well, some of the things could be tested this way, no doubt. bio |
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Post by Cybermortis on Nov 13, 2012 17:53:16 GMT
A solid block of ice with a hole drilled in it would might for a viable small-scale test idea, a lot faster and cheaper than trying to craft a cannon out of ice at the start anyway.
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Post by PK on Nov 13, 2012 17:58:36 GMT
Just a thought here... As a basic concept, a cannon is pretty much just a pipe from which you can propel a projectile, right? If we can agree on that, then it could be made pretty easily if they're going to alaska to do this. Find an iceberg/glacier and drill a hole in the side of it: Barrel. Pack it with explosives and a projectile that fits the diameter of the hole and hey presto: Cannon. If you do it low enough on the iceberg/glacier, the ice should already be pretty tightly packed and with X tonnes of ice around it, it shouldn't (easily) come apart when fired. Granted, you can't move it around to aim it, but if you can propel a projectile from it, it's basically a cannon. If we only want to have an ice cannon that can be fired then it's absolutely OK. However, if we want a cannon that has some of the other basic features of a cannon - like (controlled) mobility or the ability to be aimed - then it's much trickier with your setup bio Mobility and aiming are functions of the carriage the cannon is resting on. And I see no reason at all that that would have to be build from ice as well. After all, does a brass cannon cease to be a brass cannon just because it's mounted on a wooden carriage? Or an iron cannon? |
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Post by The Urban Mythbuster on Nov 13, 2012 18:08:01 GMT
A solid block of ice with a hole drilled in it would might for a viable small-scale test idea, a lot faster and cheaper than trying to craft a cannon out of ice at the start anyway. I know in my area, it's realitively easy to get 50, 100 & 500 pound blocks of ice (we usually use them for "chilling adult beverages"). So, I suppose small scale they could drill through the different blocks to find out the minimum thickness that is needed to avoid destruction of the cannon on the first try. |
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Post by Cybermortis on Nov 13, 2012 19:01:24 GMT
Yes and no.
Using solid blocks will give a better idea as to the relative strength of different types of ice, but it would not give you enough data to calculate the required thickness of the barrel on its own, as the solid mass would be absorbing some of the force. And that mass would not be there in a cannon, so the data would not really give you a specific figure as to the required barrel thickness on its own.
What you would have to do is use blocks of different thickness, reducing or increasing thickness until you find the shatter point pressure - and then owning to the nature of ice add some additional thickness for safety.
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