Macbeast
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| posted on 21/8/08 at 08:32 AM |
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Water Jet - wtf ??
Could someone explain to me how a waterjet cutter works ? I read about waterjet cutting of metal an even glass.
Also what is CNC pls ?
I must have been off school the day they did kit car fabrication 
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mistergrumpy
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| posted on 21/8/08 at 08:34 AM |
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I think water jet is a high pressured jet of water which contains sand as the abrasive and therefore cuts through the material.
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Project7
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| posted on 21/8/08 at 08:45 AM |
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CNC - Wiki explains it better than i can
http://en.wikipedia.org/wiki/CNC
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BenB
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| posted on 21/8/08 at 08:52 AM |
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High pressure water alone will do the trick. On submarines if a pressure pipe burst the room would often fill up with steam so much you couldn't
see where the problem was. If you used your hand you risked chopping it off. Apparantly the old trick was to hold a broom in the air and slowly walk
around the room. When the head of the broom fell off you'd found your leak....
Nice story- not sure if it's true!!!
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loggyboy
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| posted on 21/8/08 at 08:56 AM |
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Some water jet cutters dont use abrasives, they just use the sheer force of the high pressure water. Its quite easy to appreciate if you think how
much damage a simple home pressure washer can do to plastic and wood.
Wikis good for waterjet info too:
http://en.wikipedia.org/wiki/Water_jet_cutter
** beaten too it spent too long finding link!
[Edited on 21/8/08 by loggyboy]
Mistral Motorsport
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iank
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| posted on 21/8/08 at 09:10 AM |
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Here's some information from a manufacturer of the machines - both water only and water+abrasive.
http://www.waterjetcutting.co.uk/
At 55,000 psi (3930 bar) not much can resist.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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02GF74
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| posted on 21/8/08 at 09:55 AM |
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quote:
Originally posted by BenB
High pressure water alone will do the trick. On submarines if a pressure pipe burst the room would often fill up with steam so much you couldn't
see where the problem was. If you used your hand you risked chopping it off. Apparantly the old trick was to hold a broom in the air and slowly walk
around the room. When the head of the broom fell off you'd found your leak....
Nice story- not sure if it's true!!!
probably has some factual basis behind it.
Mr Ward, out metalwork teacher told a similar story about a boiler type thing. It spring a leak and you could see a thin water jet. Someone
decided to put their hand in the stream and subsequentlly got a hole in their hand resulting in having to have it amputated.
If it can go though solid steel, aluminiumj, human flash and boone is not going to challnege it.
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scootz
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| posted on 21/8/08 at 09:58 AM |
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As someone who once used a pressure washer to clean some cack off the toes of my wellies, I can vouch for the power involved... I still have the
1" scar below my big toe to remind me! 
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aerosam
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| posted on 21/8/08 at 09:59 AM |
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We have a progressive technologies waterknife machine in work. It's about the size of a house and is CNC controlled. We can vary the pressure
and abrasive content of the water to either strip coatings, (plasma, paint, rubber, adhesives etc) or completely cut through stuff.
It'll cut through pretty much anything.
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Macbeast
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| posted on 21/8/08 at 10:06 AM |
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Thank you all very much All is clear.
I find it difficult to imagine a jet of water cutting through titanium but I suppose if it were hard water ....?
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Minicooper
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| posted on 21/8/08 at 10:13 AM |
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They were and still are used in the shipyards, watching it cut 6 inch plate with ease was quite something
Cheers
David
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the_fbi
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| posted on 21/8/08 at 11:54 AM |
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quote:
Originally posted by BenB
On submarines if a pressure pipe burst the room would often fill up with steam so much you couldn't see where the problem was. If you used your
hand you risked chopping it off. Apparantly the old trick was to hold a broom in the air and slowly walk around the room. When the head of the broom
fell off you'd found your leak....
Nice story- not sure if it's true!!!
Totally true, the issue was that it was actually superheated steam rather than water which came out of the pipe, hence invisible.
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nick205
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| posted on 21/8/08 at 03:54 PM |
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CNC = Computer Numerical Control
Basically a programmed computer is used to precisely control the movement of the tool and/or workpiece via stepper motors, hydraulics etc.
Watch this you tube vid of a W16 engine block being machined from a solid billet for a stunning example of what modern machinery can do...
http://www.youtube.com/watch?v=GU32Q6QXtWQ&feature=related
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scotlad
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| posted on 21/8/08 at 04:13 PM |
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The mop story is true though the last time i saw one it was a jcloth on a broom handle. Used for finding superheated steam leaks near power station
steam turbines- you can hear the leak but cant see it as its at around 568 celcius and 160bar pressure therefore its the steam is too hot to condense
and become visible until its cooled somewhat.
[Edited on 21/8/08 by scotlad]
Wonderous is our great blue ship that sails around the mighty sun, and joy to everyone that rides along!
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zilspeed
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| posted on 21/8/08 at 05:22 PM |
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Regarding waterjet cutters. AndyW7de of this parish has one.
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nick205
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| posted on 22/8/08 at 11:56 AM |
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quote:
Originally posted by zilspeed
Regarding waterjet cutters. AndyW7de of this parish has one.
An online parish - now there's a thought
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Vindi_andy
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| posted on 29/8/08 at 03:29 PM |
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There was a guy where my dad used to work who lost his arm just below the elbow thanks to a pinhole in a high pressure hydraulic line. Basically he
didnt see the stream as the hole was so small waved to a colleague on the other side of the yard and his arm crossed the stream.
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MikeRJ
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| posted on 30/8/08 at 11:44 AM |
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quote:
Originally posted by Vindi_andy
There was a guy where my dad used to work who lost his arm just below the elbow thanks to a pinhole in a high pressure hydraulic line. Basically he
didnt see the stream as the hole was so small waved to a colleague on the other side of the yard and his arm crossed the stream.
I presumed it had to be amputated due to poisoning by the hydraluic fluid rather than it cutting his arm off? That is one of the dangers of high
pressure hydraulic systems.
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britishtrident
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| posted on 31/8/08 at 07:28 PM |
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quote:
Originally posted by BenB
High pressure water alone will do the trick. On submarines if a pressure pipe burst the room would often fill up with steam so much you couldn't
see where the problem was. If you used your hand you risked chopping it off. Apparantly the old trick was to hold a broom in the air and slowly walk
around the room. When the head of the broom fell off you'd found your leak....
Nice story- not sure if it's true!!!
You are thinking of a high pressure superheated steam leak --- you can't see superheated steam it is to most intents and purposes a gas and
completely invisible. The only warning you get is the noise. Wander past a high pressure superheated steam leak and it can instantly cut you in
two.
Big steam ships were just the dogs danglers
[Edited on 31/8/08 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Vindi_andy
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| posted on 1/9/08 at 12:42 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by Vindi_andy
There was a guy where my dad used to work who lost his arm just below the elbow thanks to a pinhole in a high pressure hydraulic line. Basically he
didnt see the stream as the hole was so small waved to a colleague on the other side of the yard and his arm crossed the stream.
I presumed it had to be amputated due to poisoning by the hydraluic fluid rather than it cutting his arm off? That is one of the dangers of high
pressure hydraulic systems.
I believe it was the fluid that cut his arm off but I could have misheard the story from my dad.
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