A part made from 2″ (5 cm) Plexiglas®
The part shown above is made from an older machine and shows corner blow-out when the machine does not compensate by adjusting feed rates in corners. Modern waterjet controllers address these kinds of problems, allowing for much greater precision than pictured above.
The same part, viewed from above
The right-hand side of the above part shows the cut with compensation turned on. The middle is with some compensation, but not full compensation, and the left with no compensation. Note the large amounts of blow-out on the left side.
Side view of what the jet does when doesn’t cut all the way through
The above picture shows 7″ (18 cm) thick Plexiglas®, which was deliberately cut too quickly. Notice the way the jet wiggles all over the place near the bottom. Predicting the behavior of the waterjet stream and moving at the correct speed are critical to properly controlling a waterjet machine.
Finished product made from three main pieces machined with an abrasivejet, then assembled and painted
Picture of an older OMAX 2652a JetMachining Center next to an Ingersol Rand SL-IV intensifier pump (on the left)
Close-up of a waterjet nozzle with an automatic z-axis
The above picture shows a waterjet machining nozzle with a Z-axis that is capable of being raised and lowered under program control. This is useful when moving the nozzle to a different location on the part to begin more machining. During this traversing, you want to avoid hitting anything with the expensive, but brittle, mixing tube on the nozzle. A good way to avoid hitting anything is to automatically raise the nozzle during traverses.
Newer machines have terrain following features that allow the nozzle to follow the shape of the material and work with warped sheets of material. The machine pictured above an OMAX 2652p, which is a more precise version of the 2652a.
Another photo of the OMAX 2652p
A piece of composite material sitting on slats
In the above photograph, notice the slats that the composite sits on. Slats are 1/8″ (3 mm) thick by 4″ (10 cm) deep. As the jet cuts, the slats get cut also, but not all the way. Part way down the slat, the jet skips to the side, and cuts no further. Slats are rotated, and flipped upside-down to extend their life. Usually slats are made of stainless steel (for cosmetic reasons), mild steel (for cost reasons), or galvanized steel (for a compromise between cost and cosmetics).
Water is in the tank to slow the jet down. Also the water level can be raised above the cutting surface for noise and splash reduction.
A logo milled in stainless steel
The above logo was done by moving the machine rapidly so that it would not cut all the way through. Milling is possible, but not yet a practical application. Some people accomplish milling by using a mask, or using low pressure or adjusting feed rates. This approach tends to work for artistic stuff, but is difficult to do on complex shapes.
A part milled from ¾” (2 cm) aluminum
It is difficult to mill aluminum because it is so soft and it’s hard to get a consistent depth of the cut. This part was done at low pressure (15,000psi). By reducing the pressure and abrasive flow rate, you reduce the cutting effectiveness. By reducing the cutting effectiveness, you can reduce the feed rate (speed) of the waterjet nozzle to get a given depth. With a low feed rate, you don’t have to accelerate the machine.
If you look at the stainless picture above this picture, you will notice that the edges of the mill are extra deep. This is because the machine has to slow down before reversing direction. When you slow, the jet has more time to cut, and thus digs deeper. By reducing the pressure, you can move slowly for the entire mill; therefore, the effect at the edges is reduced.
A reference plate bolted to a waterjet machine
One way to provide a reference point for machining is to bolt down a plate to the machine, then cut the plate using the machine. This gives you a known corner to reference to if you plan to do secondary machining on existing parts. (In the above photograph, notice the wear that is beginning to occur on the slats in the area around the reference plate.)
A ½” (1.3 cm) thick glass rose next to some ¼” (6 mm) thick marble rose heads
The above picture illustrates the technique of tabbing , which is useful for making small parts that might otherwise fall into the machine. This is done by leaving a small bit of material holding the part in place, and breaking it off later. These tabs are thicker than they needed to be because of concerns that the marble wouldn’t be strong enough to support thinner tabs. The drawback to using thick tabs is the extra time it takes to file the the tabs off.
This SeaCatch™ is made almost entirely on an waterjet
The SeaCatch is a device intended to safely release heavy loads under tension (like fishing nets, things in tow, and special effects). They come in various sizes. More information is available on the SeaCatch web site.
A part machined from 2″ (5 cm) thick concrete (it’s pink because there was a pigment added to the concrete)
If you have pictures you would like to share about something you made on a waterjet, send them by with a short description of what it is, what it is made of, and any notes on how it was made.
A 10 foot tall sculpture of a palm tree made from 1/8″ aluminum.
A custom waffle iron made from etched titanium. Required precision cutting and no room for error!
Xbox® case cutting
What happens when you use a waterjet on an Xbox case? Look at various logos and figures cut out of an Xbox.
Wooden electric guitar
Watch as a waterjet cuts out the pieces to make an electric guitar from wood.
Techniques for working with brittle materials, such as granite and marble.
When cutting laminated materials with a waterjet, you need to use some techniques to keep the water from getting between the layers and ruining the material.
A discussion about how to cut glass with a waterjet to minimize broken and chipped parts.