CNC Water Jet Cutters
CNC waterjet cutters have been around for a while but really gained momentum when the computing power was applied to the concept. Computers made it possible to predict the shape of the jet, so you could compensate for it and make predictable cuts. In broad terms, “CNC waterjet” is any kind of cutting tool that uses a high-pressure stream of water to cut in combination with a computer to direct the cut. Today waterjet cutting is broken down into two main categories, abrasive waterjet, and pure waterjet cutting.
Abrasive CNC Waterjet
Waterjet CNC’s that have an abrasive added to the water accelerates the cutting process making it possible to cut much harder materials than with water alone. Abrasive waterjet CNC’s usually use garnet with grit sizes ranging from 50 to 220 mesh, though 80 mesh is very common.
Pure CNC Waterjet
As the name implies, pure waterjet CNC cutting involves cutting only with water. This type of waterjet CNC cutting works best for softer materials. Most of the used waterjet CNC machines we offer have the ability to abrasive cut.
Deciding on the Pump Type for a Used Waterjet CNC
CNC waterjet’s come in two basic pump types: direct drive and intensifier. The direct drive pump waterjets have plungers which are driven by a crankshaft to pressurize the water. Intensifiers use hydraulic rams instead.
Direct Drive Pumps
• Simpler design but require more maintenance
• Less expensive for the initial investment
• A higher cost of ownership
• Require less maintenance
• Higher cost
• Lower cost of ownership
There are many ways to calculate the cost of making parts on a waterjet CNC. Some CNC waterjet machines have multiple cutting heads, which would affect an hourly calculation rate. Setup and programming time, the risk of breakage, the number of times a material needs to be pierced, consumable costs, and quantity all affect the cost. You’ll want to be selective to make sure the waterjet you select is a good fit for your specific job types.
Waterjet Cutting Vs Laser Cutting
Laser cutting and waterjet cutting can be used for many of the same materials. In general, the water jet is slower than laser or plasma cutting thought the speed can be increased on a waterjet CNC with 3 or 4 cutting heads. Even though it’s not the fastest way to cut, it has other advantages.
Advantages of Waterjet vs. Laser Cutting
No heat affected zones (HAZ): CNC Waterjet cutting does not distort or alter the material structure at the point of the cut due to high heat. In laser cutting material is melted, burned or vaporized away. For some materials that high heat changes the structure of the metal at the point of the cut. It also limits the thickness of a cut possible in most metals. Waterjet CNC cutting can cut thicker sheets and does not change the composition of the material. This can make roughing out with waterjet very attractive. Since the metal has not been heat-hardened or work-hardened, it’s easier to mill-finish an edge created on a waterjet than an edge created by a LaserJet CNC.
CNC Waterjet can cut materials not possible on laserjet: A CNC waterjet can cut reflective material that would be difficult or impossible to cut with a laser CNC. It’s also great for cutting materials that don’t melt easily, like granite or materials that are destroyed by melting, like laminates.
Environmentally friendly: Because CNC waterjet cut with water and non-toxic abrasives, they do not make hazardous material either air-borne or waterborne in the process. Most waterjet CNC’s come with a filtration system so that you can continue to use the same water.