Water Cutting

Anybody here play with this kind of cutter? What kind of water pressures does it take? How is the nozzle shaped internally? What kind of thickness can you cut? What kind of volume of water does it move?

Reply to
Bob La Londe
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Typical units use about 40,000 to 50,000 PSI, and maybe half a gallon/minute. The water is loaded with garnet grit to do the actual cutting. I watched a demo of cutting 1/2" diameter holes through a 4" block of Inconel, which was really quite impressive. It took maybe 2 minutes for each hole.

Jon

Reply to
Jon Elson

Yeah, that's the kind of pressure I am seeing too. Looks like there is no poor man's DIY setup for that either.

Reply to
Bob La Londe

You can use a normal pressure washer pump (1,500-5,000 PSI) to make a poor man's non abrasive water jet cutter... just like they use for cutting cakes and similar in some bakery facilities. I'm not sure how much use there is for a home CNC water jet cake cutter however.

Reply to
Pete C.

I have worked around a number of water jet machines, for both cutting and blasting, nothing about them are cheap in any way. Maintenance on those 50k PSI pumps can be brutal and filtration of the waste water expensive. IIRC, our machines had to use deionized water.

Reply to
Tim

Today's commercial WJCs use garnet, but it's interesting to note that the early experiments, and some of the early commercial units, could do some amazing cutting with water alone. In fact, I remember one company that I reported on that sold the same model to a company that was slicing Sarah Lee chocolate cakes and, in the building next door, to one that cut cement-reinforced slag-fiber ("rock wool") insulation panels.

You can cut steel with plain water, but it's very slow. I haven't kept up but I think that all of the commercial units designed for cutting metal now use abrasive grit. Still, the ability to cut with plain water is a read head-shaker, IMO.

-- Ed Huntress

Reply to
Ed Huntress

It looks like more effort than it would be worth. I covered non-traditional machining for _American Machinist_ a few decades ago and I remember the cake slicers that would also cut metal. Amazing.

-- Ed Huntress

Reply to
Ed Huntress

I was actually thinking of stone. Specifically granite, for a non traditional idea, but it looks impractical to DIY and its way to expensive to have done. Granite is cheap. Cut granite is very expensive. I was hoping to be able to make cuts up to 3-4 feet thick. Looks like I either need a $50K machine or to spend the rest of my life on one project. Neither is palatable so this idea will have to pass for now.

Reply to
Bob La Londe

Several years ago I was doing some research for investment purposes into a company that was using high pressure LIQUID Nitrogen for jet cutting. Electronic circuit boards and meat cutting were some of the uses they were investigating at that time. I filled up my flash drive where I was storing all that information and put it away. I probably should dig through it again and see what kind of progress they have made.

I think it was the University of Nevada Las Vegas that was leading the research into this along with one of the Idaho Universities. The Idaho team was experimenting with it for cutting metals IIRC.

I can think of some interesting possibilites. DL

Reply to
TwoGuns

(rough cuts would have been satisfactory. This is not for a counter top or something like that. Think bigger. A lot bigger.)

Reply to
Bob La Londe

Can you not use a wire saw something like used commercially. IIRC the old ones, before diamond coated blades, used a soft metal wire, like copper, and grit was fed into the cut and embedded into the soft blade like a lap to cut the harder material. The blade is often a continuous loop like a bandsaw. A program I saw showed that the Egyptians used the process but the saw was a hand powered reciprocating saw.

Reply to
David Billington

I knew of one used to cut a building apart, piece by piece. Slab, pillar, I-beam, rebar, pipe.... no problem.

I'm not aware they used any grit, just lots of water.

Reply to
David Lesher

to cut stone all you need is steel wire, some pulleys, something to move it, and some grit - take your time

Reply to
Bill Noble

You can drill a starter hole with a diamond core drill, although 3-4 FEET is going to be slow going. Once through, you can use aircraft cable (braid) with oil or water and diamond grit to saw it. I think that's what the pros use.

Jon

Reply to
Jon Elson

I worked with non abrasive waterjet for a number of years, uses the same type of intensifier and those things are very expensive. My stuff operated at the

50-55,000 psi range.

I was using diamond or saphire (cheap) nozzles with a 0.005" - 0.007" orifice.

Plumbing uses special connectors where the pipe is threaded for a left hand ferrule that is compressed by a right hand nut, the end is coned at ~45 degrees and the connectors have a mating cone about a degree different to cause cause an interferance fit. Plumbing tends to be 304 or 316 depending.

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To see fittings.

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They were less expensive than Autoclave back in the late 90's.

Intensifier piston rod is solid carbide on an Ingersol streamline and check valves have a short life. The best swivel is a coil of tubing. They make swivels but they tend to go for a grand+ or so and eventually fail.

Oh, there is no such thing as a minor leak in a waterjet system. The biggest issue I had with production is they liked to keep running when ever a leak started, that water cuts everything, you got to be on top of repairs or it will cost you even more.

Most of my comments apply to abrasive jet, that has a system to introduce garnet iirc into the water after it exits the orifice.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Reply to
Wes

I know Sara Lee uses waterjet to cut some of their offerings.

Wes

Reply to
Wes

Should have read all the thread before I responded to your earlier post. Was the company Ingersol-Rand?

Well there is that Grand Canyon ;)

Seriously, One of the apps I had was profiling low density fiberglass headliner shells. The waterjet nexts needed periodic repair (welding), cut the same outline 50,000 times, you will cut though the deflectors in places.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Reply to
Wes

I heard a horror story where a facility put in a reverse osmosis system to take all impurites out of the feed water. Then they started having even more problems. Really pure water attacks the alloying elements in the plumbing.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Reply to
Wes

It may have been; that sounds familiar. But it was too long ago for me to remember.

I'm not sure I followed that last paragraph. 'You want to read it again and see if it's you or it's me?

-- Ed Huntress

Reply to
Ed Huntress

It may have been taking out the iimpurities, or it may have been a pH effect from the process. Some kinds of "distilled" water are slightly acid.

So is rainwater. I understand that the latter is the result of picking up carbon dioxide from the atmosphere on the way down, and forming a very weak solution of carbonic acid. But I got that second-hand.

-- Ed Huntress

Reply to
Ed Huntress

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