Delcam’s PowerMILL 5 will offer new machining simulation options

A related development has enabled a methods-based approach to be adopted so that common features, for example, holes of the same size and type, within different components can always be machined in a consistent manner. Currently, this functionality is limited to drilling operations but it is planned to extend the approach to 2- and 2½-axis machining in future releases.

New machining options
The most important of the many new machining options in PowerMILL 5 is the improved rest roughing. This uses a new stock model approach that results in faster calculation times and increased machining accuracy to ensure that the maximum possible material is removed with each tool. The benefits will be particularly significant when machining a component with a long series of progressively smaller tools.

Another important enhancement is the ability to machine different area of the model with different thicknesses of material left on. This approach is used in the aerospace industry when roughing structural components having deep pockets with thin walls. In these cases, it is often desirable to rough machine the flat, base surfaces to a minimal tolerance for reduced finishing but to leave material on the thin ribs to ensure they retain sufficient strength while machining with the large cutter. Similarly, when machining electrodes, there is often a need to machine to the exact size of the required cavity in the axial direction but to apply a negative offset in the radial direction to provide the spark gap.

As well as being able to apply different general offsets in the axial and radial directions, PowerMILL also has the ability to apply different thicknesses to individual surfaces or groups of surfaces. This functionality is required frequently when machining mould inserts. While the core and cavity surfaces need to be machined to the exact dimensions, many companies prefer to leave a small layer of material on the split surfaces to aid in benching the tool and to overcome any risk of flashing.

PowerMILL 5 also has the ability to ignore surfaces that are not required for a particular calculation. This option can be helpful when machining products like aerospace blisks, where the same shape needs to be duplicated a number of times within the component. The user can select the surfaces making up the feature and instruct PowerMILL to ignore the remainder of the model. The toolpaths generated can then be checked for collisions with the rest of the model and, once any necessary adjustments have been made, copied around the model to produce the complete machining program. The same functionality can be used to ignore surfaces that do not require machining, such as the construction surfaces used in the creation of the design.

PowerMILL has always been acclaimed for the variety of editing options it offers to allow users to optimise toolpaths and so increase machining productivity. This flexibility has been further extended in PowerMILL 5 with the ability to edit individual segments within any toolpath. It can be used to give greater control over cutting conditions in different areas of the component and also to reorder the program to allow more efficient machining of large parts.

PowerMILL 5 also includes the ability to edit individual toolpath leads and links. This is especially important in five-axis machining, as in many cases it will not be possible to use the same style of lead and link for the whole part.

5-axis machining
Following the addition of five-axis capabilities in PowerMILL 4, work has continued to expand and improve the strategies available. Work on a range of complex five-axis machining projects has enabled Delcam to continue its long-established tradition of providing software the produces toolpaths that are not only mathematically correct but which also run efficiently on the machine tool.

For example, secondary axis limiting has been added to ensure that the program generated will not attempt to move outside any limits in the machine tool’s range of movement. Contact point analysis allows the user to ensure that only the cutting surface touches the component and that rubbing with the shank is avoided, and contact point feed rate control enables the feed rate to be set based on the cutting speed rather than the rotation rate of the tool tip. This last enhancement is of great importance when cutting some of the more difficult materials found in the aerospace industry.

Particular attention has also been give to improvements in machining based on an underlying drive surface. This technique has been made more flexible in PowerMILL 5 and so gives the user better control over cutting conditions as well as helping to minimise excessive movement of the head that can result from programs based on machining at a fixed angle to the component surface. Five-axis drilling has also been improved to give faster drilling, more comprehensive hole recognition from a wider range of CAD systems, and automatic capping of holes to prevent the milling cutter entering them.

Verification and simulation
PowerMILL 5 sees the introduction of further improvements to tool definition and collision checking. The software now has a wider range of options to simulate the tool holder and also to identify the different areas of the cutter and holder. It also allows the user to create a collision boundary around particular areas of a model, such as steep walls, or around clamps before calculating any toolpath. This approach can be more efficient than calculating the whole toolpath first and then removing and recalculating any segments that might cause collisions.

PowerMILL 5 also incorporates the first stages of full machine simulation within the software. Currently, this is limited to a range of popular standard types of machine, although customers that also own Delcam’s PowerSHAPE hybrid modelling software can create additional models of their own.

The simulations allow users to see exactly what is happening on the machine and to compare the results of using different strategies. They will be a particular benefit to users of five-axis machine tools. Even though the software does not include full verification, the simulations will indicate any areas where the machine tool is attempting to move outside its operating parameters and also any movements where major collisions could occur.

The use of these simulations will help ensure that maximum productivity is obtained from the machine tool. For example, the user can assess the effects of placing the component in different positions on the machine tool bed or can evaluate different fixtures to see which orientation of the part gives the most efficient cutting conditions.

For further information on Delcam’s PowerMILL, please contact: -
Peter Dickin, Public Relations Manager
Direct phone: 44 (0)121 683 1081 e-mail: marketing@delcam.com

Delcam plc,
Small Heath Business Park,
Birmingham, B10 0HJ, UK
www.delcam.co.uk

Delcam Inc.
3270 Electricity Drive
Windsor, Ont. N8W 5J1, Canada
www.delcam.com