Frequently asked questions

Here we have gathered the most frequent questions we get about micro abrasive waterjet technology and our product. Do you have further questions not answered in the list, please get in contact with us – we are happy to tell you more!

What materials can be cut?

The Finecut WMC500II can cut virtually all materials such as wood, rubber, glass, metal alloys, engineering ceramics, carbides, combined materials etc. It can also cut combined materials with complex structures such as sandwich materials like carbon fibre reinforced plastics with honeycomb. Harder materials such as alumina or zirconia generally require harder abrasive material to obtain an efficient cutting process.

Is there any material that actually cannot be cut?

Hardened glass cannot be cut as it has a stress balance where any disturbance will make it crack. – Diamond is difficult to cut due to its extreme hardness. Theoretically, it can be cut but it requires an abrasive material in the cutting process that is extremely hard which will give impractically short life length of the focus tubes currently available.

Why do you need abrasive material?

Soft materials can sometimes be cut with pure water. Drop erosion can actually quite quickly erode through a 1 mm steel sheet. At elevated pressure (6000 bar) trials show possibility of cutting 3 mm titanium. Anyhow, most dense materials of higher strength will require that you add abrasive material in the jet in order to be cut efficiently. Water itself is not erosive enough to quickly remove material and cut through, the particle erosion from the abrasives makes the cutting process more aggressive. You can use abrasive of different materials and sizes and you need to select the abrasive with respect to the hardness of the material you intend to cut, the size of the focus tube etc.

What is the difference between traditional abrasive waterjet cutting and micro abrasive waterjet cutting?

The micro abrasive waterjet cutting system is optimized and scaled down which entails the possibility to work with a kerf down to 0.2mm. With the small kerf you are able to cut complex, narrow geometries. Micro abrasive waterjet cutting requires a very stable and precise machine. Finecut WMC500II has a motion system which is mechanically linked to the workpiece. Hence, the rigidly linked system will be less sensitive to external influence.
A traditional setup with the workpiece being clamped on a separate table and the motion system generating the cutting path being part of another structure add a risk of errors generated from relative motion between the structures caused by external disturbances. Micro waterjet consumes significantly lower flows of water and abrasive material. Although precision powders are more expensive, the low consumption makes the total cost lower while the added value to the products can be higher. Traditional abrasive waterjet is more powerful and can cut thicker materials, but is typically rougher and used in applications which require less precision.

How fast can you cut?

The speed of cutting depends on material properties and thickness of the material you want to cut. The harder and thicker the material is the slower you need to cut. If you want smooth, fine surfaces the cutting speed need to be reduced. The Finecut WMC500II can move the cutting head with a speed of 20 m/min but it is very few materials that actually can be cut with this speed. As with any abrasive waterjet cutting speed till affect the quality of the cut. To make an example the FAW300 cutting system can make a separating cut in 3 mm thick stainless steel at 300 mm/min. but more typically 60 mm/min or even 30 mm/min are used depending on the application and precision requirements.

Can you remove material without cutting through?

Yes, the Finecut WMC500II can be used for milling purposes. In fact, milling capability has been one of its design criteria. The encapsulated design and powerful direct drive motion system makes it suitable for milling. The control system has look ahead as well as machining condition selection function, the latter allowing to have different servo parameter settings, optimizing either velocity or path accuracy.  Hence, by selecting appropriate nozzle combination, water pressure, abrasive flow and controlling the traverse speed of the jet you can choose if you like to cut through or only remove material to a desired depth. 3D surfaces can be achieved by scanning over the surface. The highly dynamic motion system allows for variable depth control by speed variation while traversing over the work. There are several different approaches to milling strategies that can be applied.

How thick/thin material can you cut with the micro abrasive waterjet?

The slower you cut, the thicker and harder the material can be. It means that you can cut thick material but the process will be slow. If you increase the waterjet size and the size of the focus tube, the flow of water and abrasive will increase and the cutting will go quicker but it will still be difficult to meet high tolerances for parts cut out of thick materials. We generally say that the Finecut WMC500II is suitable for cutting materials up to 30 mm thickness but there are always exceptions depending on material properties and quality requirements. If you need to cut thicker parts you can fit an AWJ cutting system in the machine. The limit for cutting thin materials will depend on how you can solve the fixturing and material handling. The Finecut WMC500II generate very low cutting forces but still thin material might move only by the airflow around the jet and need to be fixtured somehow. The machine itself has no limit in how thin materials that can be cut.

What do I need to think of before installing Finecut WMC 500II?

The Finecut machine requires a controlled environment to fully take advantage of its precision capability. The temperature should not vary much and preferably be kept around 20° C. The fine abrasive powders are sensitive for moisture and should be kept in dry air. The machine has adjustable rubber damped feet but the floor should not vary more than ca ±10 mm beneath the machine. The machine has a small footprint and does not affect the near environment. We have customer applications where the Finecut stand side by side with high precision milling centers. The pump can be placed in a separate room. As the consumption of high-pressure water is low the effect of distance between pump and machine is not a problem. The machine needs a supply of electric power, pneumatic air (6.5 bar, dry and oil free) and water. Good water quality is essential for the operation. We can supply water treatment if it is needed. As the process use water there will be a continuous water flow to the drain.

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