CNC Water-Jet cutter DIY?

[BearNPum]

Anyone attempted this, or know of any good resources to look at. Anyone know anything about water-jet heads, like how to home brew or buy for a reasonable price?

[BearNPum]

Umm, I better stick to a "gadget" like CNC for metal only. Found this:

"My 2 cents
I love the idea of a home sized water jet

We are working on a low cost water jet pump for machine tool cutting. Low cost is $20 to $40,000 compared to $75 to $300,000.

For a DIY homebuilt system it is expensive. The preasure fittings for the tubing may look like a fitting from home depot but to withstand 50,000 psi you are looking at a average of $100 per fitting. Yes I am using stainless steel 1/8" dia ball bearings for the valve but they cost $10 each and I replace them every 100 hours compared to the new ruby valves at $300 each. The nozzles for practice are saphire at $25 each but last 15 min to 60 min before failure. So a good diamond nozzle is $500 each and they are good for 100 to 500 hrs of use. The stainless steel tubing that is rated for 50,000 psi is $10 to $20 per foot.

For this prototype design I am using a 10 bhp motor geared to 35 RPM's for a torque power of greater than 12,000 lbs. The gear drive cost is about $3000. Then I load that into the 1/2 diameter ceramic/stainless plunger that has a 3" diameter solid stainless steel cylinder designed to have a burst pressure of 80,000 psi. Just for safety instead of 2 1/2". I have multiple safety valves with rupture disks that are $200 apiece and cost $25 to replace a disk.

I have had long conversations with several top high pressure pump designers and a couple of engineers that received a PhD in ultra high pressure and they have all stated that I have a good solid design.

The tolerances for the seals are .0001" There are a couple of fittings that we have tolerances at .000025. You are wondering why the extreme tolerances. At these presures microcracking can occur and the cylinder head can rupture. The force is like a 50 cal rifle going off. The valves can fail if designed wrong and the same thing can happen the cylinder head can rupture. You use the wrong fittings and the failure is the same as a 50 cal rifle going off.

Maintanance on a $200000 unit is every 1000 to 2000 hrs on my design for safety it is every 100 hours. All valves are replaced all seals are replaced. About $200 to 500 each time.

So why am I doing it. Just because I want to. Geeeeee why would any body build something when they could buy it. It is the challange of doing something that no one wants to do. Its called I don't have a dating life so I have to occupy myself with something else.

I hope this helps I spent a year designing and studying and asking a lot of questions for my design."

[Mike94531]

I cannot find the info now, but I know for the home-type pressure washers, you can get an attachment for sandblasting at the same time as pressure washing, if you modified the nozzle so that instead of a wide spray the sand came out in more of a "line" wonder how that would work?

depending on what you want to cut, maybe you don't need as much pressure...new pumps can be bought from Northern Tool...one of these days I too would like to experiment with this..

[Gadget]

The high pressure is too scary for me. A blowout could make for an early checkout.
Dan

[woofer456]

I know this: We (where I used to work) built tanks and piping for a Co. that manufactured hi pressure water torches, I was fortunate to get a demo of the finished product, it was the real deal, the thing that caught my attention was the three pumps used in line to produce the pressure for cutting they were three 30 hp motors.... The price they wanted for the unit was around $250,000. more than I can handle.

Good Luck with yours.
Bob

[Mike94531]

when I 1st started looking into making one my plan was to use a gas engine, I have an extra 2.3liter 4 cylinder car engine that I thought would work okay for the power....now it might be used for a generator instead