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Effortless Cutting Blades?
knewter asks: "I've recently come across an application in a machine that my company is building in which we need to be able to cut a piece of hardened plastic without jolting the item from which we're cutting it. We've researched (mildly) some alternatives, and right now we're looking at ultrasonic knives. Unfortunately, these tend to be rather expensive, and as we're a robotics engineering firm, we'd like to keep the cost of the extraneous pieces of machinery negligible (this is a convenience feature). We've also looked at cutting it with a hot wire, but I personally am worried that this would taint the test results (it's in a sort of a plastic vial that is drained for testing purposes). Does anyone here have any ideas on what would be proper for this, or even some ideas on cheap nano-machinery (not in the sense of manipulating small particles, but in the sense that the blade has been refined to an extremely small point and will not require repeated sharpening)?" Of course, the obvious answer is a laser of some sort, but lasers aren't necessarily cost effective. How about high pressure water cutters?
I recently got the oportunity to play with some neat equiptment like what you are talking about. It was a ultrasonic wave knife. 1" thick iron at 4"/second. Very fast, and it required very little maintainence,(mostly on the robotic arm).
;]
It was a dream. My company was working on a contract for NASA. We were cutting open part of a shuttle that still had some flamable compound in it. I took the machine home for an hour to cut up an old computer case I had sitting around.
Dont worry, I gave it a deserving burial.
It slices, it dices, look at that tomato!!! You can even cut a tin can with it... but you wouldn't want to!!!
Just use 10Kv across the chassis.
- A.P. (it's a joke, a sly one)
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* CmdrTaco is an idiot.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
It's my opinion that the case did not deserve to be cut up and buried. If you can't find a use for it, find someone who can. That said, I doubt if the case contained any lead. The electronics mounted in the case no doubt use lead/tin alloy solder but the case is probably just steel and recycled dinosaurs, i.e. plastic.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Where do you hear these things? A case is unlikely to contain any lead - just steel, aluminum, etc. Circuit boards do contain lead, though, as do monitors (which is why it is now illegal to put CRTs in the trash here in Massachusetts).
They might be able to teach you this at Wudan, but you still need to get the Green Destiny to make the cut nice and smooth. :)
Pair up in threes. - Yogi Berra
There is also something called "amorphous metal" or "met-glass" which does not need sharpening.
I guess the important thing is that you did not indicate whether you were trying to shear the material or cross cut it. This makes a difference in the materials and the methods.
Ummm, Jon, aren't you supposed to be dead...? - Otter(3800)
We present to you, exibit B, that the above prosecuting attorney is actually a troll. The defense rests.
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One future, two choices. Oppose them or let them destroy us.
(Really) small pieces of glass shot through a pressure gun in an enclosed containter. The auto shop at my school uses somthing like it for polishing - but if it's concentrated, then it will cut...
ALL YOUR BASE ARE BELONG TO US!
SIG: HUP
They teach a plethora of cutting techniques. I strongly recommend Crouching Tiger Hidden Dragon for a further demonstration of the Wudan's cutting techniques.
One word of advice: if you do attend the Wudan school of martial arts then stay away from the edge of the bridge. The railing isn't very high and it's easy to jump/fall/float off.
Keeping
You can also cut with high pressure water jets (several hundred bar). However, I don't know the costs of this technique. Look for "water jet cutting" with google or take a look here.
I would go with laser. I don't know about prices, but you could probably have a company come and do it for you much cheaper than buying the actual equipment. I you could use heat, perhaps just take a hot soldering iron (100 watt) and slowly melt it away, it might take a while and won't look perfect, but it might do the job.
I've just had a lot of my teeth drilled using a similar method. They call it 'air abrasion' - basically sandblasting your teeth with Aluminium Oxide particles.
o n
Links here: http://www.google.com/search?q=dentist+air+abrasi
So far I've not needed anesthetic for any filling, and this is after 18 years of neglect, so you can see that it's fast and very precise.
Matt (with a lovely new grin)
I was wondering if maybe it'd be possible to use some HCL (Hyrochloric) or H2SO4 (Sulfuric) acid in a precise manner to eat through the plastic exactly where you want it. Naturally this will come with some serious safety concerns, but it should be possible to accomplish what you're looking for. The trick will be using the right amount in the right spots.
Of course, this might not be as time-efficient as a cutting method, but it might do the trick.
You can accomplish anything you set your mind to. The impossible just takes a little longer.
Just thought I'd warn ya, if it's a really old case it may not be legal to bury it. I hear that old computer components used to be full of lead, which in many places is illegal to dispose of in just any manner.
:) It sounds like it could have been lots of fun!
As for having fun with the tool, I envy you
You can accomplish anything you set your mind to. The impossible just takes a little longer.
Abrasive (or non-abrasive depending on the material you're trying to cut) water jet would do what you want quite well. These are not cheap systems either, though. check out http://www.usjetting.com or http://www.woma.de for systems (I've not purchased from them nor am I affiliated with them).
There are also very thin abrasive cutting blades that might do what you want. The problem with water jet cutting is the water, which for some applications produces unacceptable contamination (not all materials like water). Abrasive cutting blades are easy to replace and have good cutting life on softer materials. Check out http://www.dynacut.com
Using cut wires is probably the cheapest solution provided that you have the capability to produce those. If you're using hot wire cutting, it might not be worth it depending on the material your trying to cut.
Lastly and out on a limb, if the plastic is conductive (or if you wanted to try your hand at fabricating a microwave torch instead... all the one's I've used are DC but I've seen specs for microwave torches for chemical applications) you could try using a plasma torch on it. You can get a .01" kerf on
a good one (for cutting 1/4" plate steel) and
they are a dream to cut with -- as good as a laser
with the convienence of a torch.
I've heard that if you concentrate a large amount of heat on the piece of metal you are trying to cut and use large amounts of pressure that it will break apart like a knife through butter.
Buzz Off