Since the conception of Abrasive Waterjet Cutting the process of material cutting has been utilized not only in 2D (Flat Sheet) applications but also in 3D (5-Axis) applications. In the past 15 years the application of 5-Axis has devolved back into the flat sheet cutting realm of waterjets where enterprising companies promised it would provide better speeds and higher tolerances in flat parts. In this exclusive article we use our experience and our users experiences to delve into the different forms of 5-Axis waterjet cutting, what it all means, where it applies, where it doesn't and how you can determine if 5-Axis Cutting is right for you.
What is 5-Axis Waterjet
Customers and Sales professionals alike have lumped many different categories of waterjet cutting into the designation of “5-Axis” waterjet. Let’s break this category of designs down for the user into 4 basic categories of machine designs:
The first 2 types of “5-Axis Waterjets” are application driven and typically will be designed or configured to meet the customers specific requirements. The later 2 are by far the more common and popular options and are merely adaptations on an existing machine design offering to improve or enhance performance and capabilities of an otherwise typical flat sheet cutting machine.
While all systems are theoretically “Robotic (CNC) Controlled” there are several manufacturers that have taken an “Off-the-Shelf” Robotic Manipulator/Arm and attached a waterjet cutting head to it. Although these waterjet systems are merely a Robotic Arm with the waterjet cutting head attached they can be very useful given the right application as they are very adept and capable given the flexibility of the robotic arms motion capabilities. In difficult to reach and cumbersome applications the robotic arm can be a great benefit. However there are some major drawbacks to this approach.
These systems are typically a “Teach’ type robotic motion system that require much more setup time then a typical flat sheet cutting system and although these very flexible systems that can cut flat sheets of material, their main purpose are cutting unique contours and shapes in 3 dimensions most of the time. Their setup, safety considerations, fixturing and programming can be difficult and cumbersome, however that is easily made up with their unique flexibility and abilities if your applications are large and complex 3D shapes 90-100% of the cutting time. For most shops cutting shapes out of flat sheets, these type of 5-Axis Waterjet systems are unwieldy, unsafe and difficult to operate.
These systems are generally found in cutting applications such as architectural, artwork, high production of difficult to machine components and extreme environments such as nuclear applications.
Bridge Type:
These systems are most utilized in applications such as Aerospace, Marine and Prototype Shops.
The most common types of 5-Axis Waterjets found will be Waterjet Flat Sheet Cutting Systems fitted with an optional 5-Axis Head and the more common, albeit limited version, the Taper Compensating head.
Taper Compensating Head
One major effect of the process of Waterjet Cutting needs to be taken into consideration when choosing these type of
Benefits:
Reduces or Eliminates Taper in Waterjet Cut Parts
Increased Speed While Maintaining Geometrical Accuracy
Disadvantages
Complexity of Design
Increased Setup Time Required for Part Probing
Increased Maintenance and Repair
Sheet Flatness a Requirement.
Exact Nozzle Offset (distance of nozzle to material) a Requirement.
Does Not Eliminate “Striations” Occuring at High Speed.
Probing Material Surface Required
5-Axis Head
Buyers have considered 5-Axis capabilities in the past for many of the wrong reasons. Although these systems provide you the abilities to cut features such as chamfers and straight bevels you should never justify your purchase, or use your machine to these, or any feature that can easily be done on an outside operation, and here is why; Your waterjet operates at a cost of about $30-$35 p/hour - That's just the amount that it takes to feed the “beast” (garnet, consumables etc.). If you can chamfer a hole on a drill press in 30 seconds your cost will be much cheaper then having the waterjet head articulate that angle over several minutes, likewise for weld prep bevels etc. The general rule is: If You Can Cut It Off The Jet, Do It! It's Just Cheaper.
Pros of 5-Axis
Ability to Cut Acute Angles of 45 Degrees or More
Can Provide Same Additional Benefits of Taper Compensating Head
Cons of 5-Axis
Complexity of design
Increased Setup Time Required for Part probing
Increased Maintenance and repair costs
Sheet Flatness a requirement.
Exact Nozzle offset (distance of nozzle to material) a requirement.
Does not eliminate “striations” occurring at high speed.
So the original question was; Is 5-Axis Waterjet All Wet?
If you have the right application, 5-Axis waterjet cutting can be extremely profitable. Whether it’s a Robotic Arm, Gantry Type or even the 5-Axis Cutting Head attachment, these applications can be real money-makers for a waterjet cutting system and a waterjet job shop. However, the Taper Compensating type heads require a deeper and more thorough review, as typically, where you need straight and good geometry, you also need a smooth and precision finish and the only way to accomplish that is to just slow the feed rate down, which in kind produces straight and clean edges, thereby making the argument for these type heads considerably less valid.
If you would like to discuss with one of our experts how a 5-Axis Waterjet Cutting System can work for your application, or if you would like to discuss adding the capability to your next machine just contact the experts at Southern Fabricating Machinery Sales today! Call us directly at 813-444-4555 or visit us on the web at WWW.SOUTHERNFABSALES.COM
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