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Post by the light works on Jan 25, 2015 5:01:52 GMT
well, the only cred anyone gets is for the intro - the two myths tested were not ones I recall seeing discussed.
that said, they were well selected. and well tested.
for the first one, my primary complaints would be that they appeared to have a larger hole in the logs they used for their cannons. of course, this means that all the reasons why it failed were even more so, except that they had a larger combustion chamber - which is probably not enough to make it work. I am curious to know if a person could make a wooden cannon work using propane and oxygen as the propellant. I think it would take soaking the wood in a sealer, making a special combustion chamber, and using a sabot on the projectile.
for the second, I will just say, it was very educational.
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Post by GTCGreg on Jan 25, 2015 15:14:40 GMT
For the log cannon, they tried to duplicate the one in the A-Team episode as closely as possible including the size of the bore and projectiles. Also, no sabot was used in the A-Team cannon.
I was still surprised it didn't work better especially with the foam "piston" attached to the back. I was watching it with my son and when they added the O2, I said to him that the log would probably blow apart. I sure called that one! I really liked the design of the launcher they finally did come up with.
I enjoyed both myths and am really liking the new show format. For me, it's more the science and mechanics and they are covering that in much more detail now. Also Adam's and Jamie's personalities are coming out much more now and they appear much more relaxed and natural.
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Post by the light works on Jan 25, 2015 15:45:19 GMT
For the log cannon, they tried to duplicate the one in the A-Team episode as closely as possible including the size of the bore and projectiles. Also, no sabot was used in the A-Team cannon. I was still surprised it didn't work better especially with the foam "piston" attached to the back. I was watching it with my son and when they added the O 2, I said to him that the log would probably blow apart. I sure called that one! I really liked the design of the launcher they finally did come up with. I enjoyed both myths and am really liking the new show format. For me, it's more the science and mechanics and they are covering that in much more detail now. Also Adam's and Jamie's personalities are coming out much more now and they appear much more relaxed and natural. to me, the bore in the clips looked much looser than the bore in their test cannon - and the walls looked much thinner. |
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Post by the light works on Jan 25, 2015 15:47:03 GMT
it occurs to me that maybe the A team did not ignite the propane as propellant, but used it as an "air" gun. I still don't think it would work, due to the lack of seal around the projectile.
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Post by GTCGreg on Jan 25, 2015 18:24:35 GMT
it occurs to me that maybe the A team did not ignite the propane as propellant, but used it as an "air" gun. I still don't think it would work, due to the lack of seal around the projectile. The vapor tank pressure of liquified propane at room temperature (70ºF) is only around 110 psi. Unless you have a really large valve and hose, like the one they used on the chicken cannon, not really much to work with. As you pointed out, they just weren't getting enough of a seal between the projectile and bore wall. |
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Post by breesfan on Jan 25, 2015 19:42:21 GMT
I liked this one. I didn't think the cannons would work though but it was fun to watch.
The manhole cover one is interesting but I have a problem with one thing. Is there a little area where you could stick things in that is close to the cover?
Adam looked cool with that chocolate cigar in his mouth.
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Post by Antigone68104 on Jan 25, 2015 21:19:25 GMT
I was never a huge fan of the A Team, but I enjoyed this episode.
The wood-chucker was an interesting build. I found myself wondering if they could have used the other wheel from the trailer, unpowered and on the other side of the ammo holder, to reduce friction as the ammo was shoved into the powered wheel. But given how well it worked, I don't think it was needed.
Usually if a myth calls for dynamite, they use a safer explosive with similar properties. I wonder why they went with the real thing this time?
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Post by watcher56 on Jan 25, 2015 21:35:51 GMT
I was never a huge fan of the A Team, but I enjoyed this episode. The wood-chucker was an interesting build. I found myself wondering if they could have used the other wheel from the trailer, unpowered and on the other side of the ammo holder, to reduce friction as the ammo was shoved into the powered wheel. Looked like they had a large ball bearing on the unpowered side. |
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Post by Cybermortis on Jan 25, 2015 22:09:03 GMT
Insurance most likely. Either they can afford to cover the costs of using somewhat more dangerous materials, or Adam and Jamie are considered more qualified and responsible so have lower premiums.
Consider that the build team have not only thrice invertantly caused property damage, Knock your Socks off blew out windows, they blew a hole in the wall of their original shop into the offices next door and of course there was the incident with the cannon*. Each of them has also came close to injuring if not killing themselves at least once, Kari caused M7 to be evacuated (this was either exploding pants or when they were trying to make gun cotton, if not both occasions), Grant came close to getting crushed when he fired an unsecured air-cannon and nearly disembowled himself and Tory has injured himself at least twice. Given such a record it would hardly be surprising if their insurance premiums were a lot higher than for A&J, who have never (as far as I can remember) caused invertant property damage nor come close to killing themselves.
(*Neither was actually the fault of the build team. The former was a screw up by their explosives expert, the second an accident that could not have been predicted - and probably couldn't be duplicated if they had tried.)
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Post by the light works on Jan 25, 2015 22:24:02 GMT
it occurs to me that maybe the A team did not ignite the propane as propellant, but used it as an "air" gun. I still don't think it would work, due to the lack of seal around the projectile. The vapor tank pressure of liquified propane at room temperature (70ºF) is only around 110 psi. Unless you have a really large valve and hose, like the one they used on the chicken cannon, not really much to work with. As you pointed out, they just weren't getting enough of a seal between the projectile and bore wall. it looked like the A-team model used 1" plumbing pipe in the build. it's be nice to have a youtube clip of it to investigate. - my google-fu is insufficient. |
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Post by the light works on Jan 25, 2015 22:24:51 GMT
I liked this one. I didn't think the cannons would work though but it was fun to watch. The manhole cover one is interesting but I have a problem with one thing. Is there a little area where you could stick things in that is close to the cover? Adam looked cool with that chocolate cigar in his mouth. most manholes have rungs cast into the shaft. it would be theoretically pretty easy to hang the dynamite from one. |
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Post by blazerrose on Jan 26, 2015 1:37:31 GMT
While most of the episode dragged a bit for me - after all, they've tested tree cannons before - I love-love-loved the part about the build in the "abandoned" wood shop. This is where they are so perfectly in their elements, and it was a joy to see the joy in them.
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Post by GTCGreg on Jan 26, 2015 2:52:04 GMT
I love-love-loved the part about the build in the "abandoned" wood shop. Reminded me a little of Junk Yard Wars. Here's what you have, now build something. |
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Post by ponytail61 on Jan 26, 2015 4:07:09 GMT
The vapor tank pressure of liquified propane at room temperature (70ºF) is only around 110 psi. Unless you have a really large valve and hose, like the one they used on the chicken cannon, not really much to work with. As you pointed out, they just weren't getting enough of a seal between the projectile and bore wall. it looked like the A-team model used 1" plumbing pipe in the build. it's be nice to have a youtube clip of it to investigate. - my google-fu is insufficient. Here is the full episode. The cannon build starts at about the 37:00 min mark |
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Post by the light works on Jan 26, 2015 4:32:42 GMT
it looked like the A-team model used 1" plumbing pipe in the build. it's be nice to have a youtube clip of it to investigate. - my google-fu is insufficient. Here is the full episode. The cannon build starts at about the 37:00 min mark I will have to wait until Friday - that much video will burn my download allowance for the day. |
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Post by ponytail61 on Jan 26, 2015 4:53:03 GMT
Here is the full episode. The cannon build starts at about the 37:00 min mark I will have to wait until Friday - that much video will burn my download allowance for the day. Go here and put in the link to video and pick the start time you want. youtubetime.com/I tried linking it that way but the forum reverted to the full video. Actually you could just copy and paste the video link you see when you use quote. That one starts at the 37 min mark. |
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Post by the light works on Jan 26, 2015 4:57:17 GMT
I will have to wait until Friday - that much video will burn my download allowance for the day. Go here and put in the link to video and pick the start time you want. youtubetime.com/I tried linking it that way but the forum reverted to the full video. here is the link to copy & paste. hm, that looks like it works |
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Post by the light works on Jan 26, 2015 5:07:00 GMT
looking at the size of the plumbing feeding the cannons, and the fact the A-team montage showed them chiseling out the barrels. I think there might be room for a revisit. they are necked up to at least 1 inch rigid pipe, and possibly up to 1.5 inch. of course, I think it will still fail.
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Post by GTCGreg on Jan 26, 2015 5:17:00 GMT
Here's a screen capture of the gas distribution system. They used a small propane tank to fill a larger tank that was connected to the two cannons with solenoid valves. This may indicate that the 2X4s were propelled just by the pressure of the propane as there was no apparent ignition system shown. The second photo conterdicts this, however, as each time a cannon was fired, there was a big explosion followed by a fire ball.   |
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Post by blazerrose on Jan 26, 2015 7:33:52 GMT
Nuthin' like a little black powder to make things look cooler.
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