The Simple Anatomy of a Water Jet Cutting Machine

May 14, 2019 by Bob Wilson

Think of the water jet cutting machine as a precision, quick erosion machine. You know, erosion like the Vermillion Cliffs National Monument or Grand Canyon in Arizona, but this is in your workshop and cutting almost any kind of material fast and accurately.


But how exactly does this water jet cutting machine work and how is it put together, you ask?


To get you acquainted with this extremely useful piece of equipment, we’ve put together this quick overview of the waterjet machine. Keep reading to beef up your knowledge and see if it’s right for what you’re doing. Then give it a whirl. Or maybe that’s more like let those abrasive water jets do their thing to help you with your business.


Anatomy of a Water Jet Cutting Machine

Let’s look at the components that make up a waterjet machine. Together they function to create an effective abrasive waterjet cutting system.


The High-Pressure Cutting System

This part of the machine is what does the cutting. It’s made up of the high-pressure pump, the cutter, and the waterjet plumbing.


The High-Pressure Pump

This pump pressurizes the water and gets the high-pressure water to where it needs to go: to the cutting head. Think of it like a quarterback making an awesome, fast, precision throw but really powerful. Think 50,000 psi. And know that the firetruck attack hose pump has to have minimum test pressure of 275 psi.


The pump used for waterjet cutting is either a classic complex intensifier type of pump or a simple crankshaft-driven triplex plunger. The newer crankshaft pump rates higher on efficiency since it doesn’t use a hydraulic system that takes up all the power. It’s a mechanical direct-drive system so all the power goes to the cutting nozzle. It’s about 85 percent to 65 percent delivery for the crankshaft versus intensifier.


The intensifier system still works though with hydraulic pressure over water. The giant motor with high horsepower pushes the hydraulic pump. This builds hydraulic pressure that pushes the piston in a cylinder.


The Cutting Head

This cutting head made of stainless steel tubes is often computer-driven and lets the waterjet bend and curve as it cuts to give you the accuracy you want. No corners are undercut and you won’t swing wide on those curves.


The Nozzle

The cutting head is in the nozzle. The high-pressure water comes in from the pump. It goes through the strong orifice in the nozzle. The orifice is made of a material that is tough enough so that the abrasion doesn’t wear it down, like sapphire or diamond. The diameter of the orifice is about 0.0005 to 0.020 inches. The orifice guides the water to help it cut the material.


To cut the tougher materials, a granular abrasive comes in after the high-pressure water comes out of the orifice in the venturi section. There is a mini hopper that feeds the abrasive material, often garnet. It’s mixed together in a mixing tube and jets out at explosive speed. Think four times the speed of sound and able to cut through a foot of steel.


The Bulk of the Machine

This part includes the material catcher tank, the wrist axes of the cutting head, and the X, Y, Z axes traverse system. There is also the abrasive bulk feed hopper and the cutting This part is the support system for the waterjet cutting mechanism.


The Material Catcher Tank

After the high-pressure water and abrasive material blasts out of the nozzle and through the material, it ends up here. It’s built to take the energy and deal with it to exhaustion.


The Traverse Axes Systems

This system of X, Y, Z axes and cutting head wrist axes allows you to move the waterjet nozzle and aim it accurately. A gantry that is bridge style controls the cutting head and lives on the X and Y axes. Thanks to this system, you can create the desired and precise cutting path.


The Cutting Board

This is where you put the material to be cut. It has clamps to hold the material and often consists of water bricks. It’s rugged and sturdy and allows you to position the material precisely to work with the rest of the system.


The Abrasive Bulk Feed Hopper

This hopper contains a bunch of the abrasive material, often garnet, that you feed in after the orifice. It feeds directly to the mini hopper. This bigger storage hopper lives on the Z axis.


The Control System and Dashboard

A waterjet cutter comes with a computerized control system and a handy dashboard that you can manipulate. It’s all software driven. It can take CAD/CAM files and turn them into G&M code to maneuver and work the waterjet.


Ideally, you want an experienced, professional technician to operate your machine and the software and you can bring projects to a professional in waterjet cutting services for manufacturing. If you buy your own machine, be sure to train the technician well. Still, rest assured that the interface is friendly.


This part of the machine is a separate item. Often it sits atop a cabinet that contains a position and feedback system as well as the drive motors.


Putting the Water Jet Cutting Machine to Use

Waterjet cutting is ideal when you need custom-made components. Experienced technicians know how to use the machine to your advantage and come up with innovative ways to make your parts. You should go with professionals that work with you to consider your product design and talk to you about how to use the cutter to create the solutions you’re looking for.


Items you can cut with a waterjet cutting machine include rock, granite, steel, aluminum, glass that’s non-tempered, wood, tile, and more.


Get Started With Your Project

Now that you know how this powerful water jet cutting machine works, you’re probably jumping for joy if you need precision cutting for those tough materials. Do you have to make components for a new project? Or maybe you want to better and more efficiently make current manufacturing projects sing.


Either way, contact us to talk about how our waterjet cutting can help your business. We’re here to answer questions about the process and talk about your projects.