In a two part product review, Al Dean, editor of Develop3D takes a look at the latest release of VISI, a system with incredible power that has been driven by one of the most demanding industries for geometry wrangling: mould and die.

For those unfamiliar with the names VISI or Vero, the company has roots within Italy’s Olivetti Group, and has been quietly working away with both in-house developments and acquisitions over the past few years to create VISI, one of the true, fully featured CAD/CAM systems. To qualify that, very few cover the majority of bases – which is what VISI is increasingly able to do. As you might expect, when you have a manufacturing focused system, there’s always a core concentration of mould and die – whether it’s part of a grand plan or a happy accident. When you find CAD/CAM developers that do a good job, they’re typically mould and die focused.

VISI covers much more, with full support for all manner of machining (3-axis, 5-axis and high speed machining), but also into lesser known – but increasingly critical – areas such as progressive die design and mould flow analysis. In the first part of a couple of reviews looking at specific areas of VISI 16, we’re going to focus on the 3D modelling portion of the offering. VISI is a fully featured hybrid modelling system, allowing you to work with surfaces and solid data in a free-form manner. Intelligence is added to your model where appropriate, but in comparison to many mainstream systems, its tools for working with large quantities of problematic geometry are excellent. When dealing with a complete mould stack, you could be looking at 2,000 plus parts. It might not sound huge, but when you consider that many of those parts are going to contain complex surface data, the power becomes apparent. Rather than going through the whole system, I’m going to have a look at some of the updates to V16 which have made it even more efficient in a pressurised production environment.

User interaction and experience
The VISI UI has been overhauled over the last few release cycles and its appearance and workflow are now fresh, modern and clearly laid out – you certainly wouldn’t think it was the first system to implement Parasolid on the Windows platform. This release sees core enhancements aimed at making navigation of the 3D model easier, a good example being view rotation. The middle mouse button rotates the model, but hot zones have been added around the edge of the screen so that clicking that middle button near the top, bottom or sides will lock a virtual screen axis for rotation – making precise rotations of your model much easier. Another pretty cool update is that CTRL+F2 will snap the view to the nearest orthogonal view.

Alongside the usability improvements, there are some updates that make working with geometry much easier. There’s been a continuation of the consolidation of commands that’s been a theme in the last few releases. This now sees many common or similar commands merged into a single operation that covers all use cases – a perfect example is that previous releases had separate operations for extruding surfaces solid and now there’s just one extrude command. As a brief guide, 30 commands have been reduced to ten or so. As we’ve said, VISI’s background is not part authoring, but working with other people’s data – specifically improving bad data so it can be used in the unforgiving production world. Tools like the new Dynamic Surface Analyser give you an understanding of how a model is constructed, and that offers you more information to base your edits on. It provides you with dynamic information about the geometry such as relative and absolute co-ordinate positions, fillet radii, draft angle, geometry type and important CAM attributes such as hole type and drilling information. Any trimmed geometry is also presented as a wireframe ghost in its natural untrimmed state (which is vital if you’re editing surfaces).

This release also sees a lot of work done to make the system more productive, by taking a common workflow, usually entailing many steps and carrying them out in a single operation. A fantastic example is the re-trimming tool, which has been reworked to carry out an untrim/fix/retrim/merge series of operations in a single step. Streamlining these repetitive tasks will certainly free up the designer and generate huge time savings. Another is the new auto-constrain surface, where you select the geometry on which you want to build a surface and the system finds the best type of surface to use, reorders the curves and generates the surface based on geometry criteria, again in a single step. Perhaps the ultimate example is the bend relief operation, used on stamping dies to great effect. To create the die face, you need to create an offset but this can cause problems with tight radii and tears or metal creasing in production. So the system has tools which can add ‘bend relief’ to those tight radii.

There are a couple of other updates that can assist work with problematic data, one of the most interesting being the Validate Bodies operation. This analyses your model to find faces that might cause problems downstream (self intersecting faces or inconsistent edges for example) when you’re trying to form a solid body, and fixes them. This is the sort of thing that could really drive you crazy as you chase bad surfaces around a model trying to form a solid object.

Compare & contrast
If you work within a sub-contract environment, then you’re going to be very used to design changes or late stage revisions in designs. When you work with mould design, you need to be sure that you get that mould on the machine and have it cut in as short a time as possible – changes come in late, but you can’t afford for these to delay things. This scenario highlights a tool that should take identifying design changes down to individual surface entities. This tool compares two geometry files, and colour codes the faces to show which are new, have been removed or added. The system will explode the geometry into sheets separated by colour/status. You can then quickly choose which geometry to swap out and replace with newer data revisions, and form a cohesive model in an incredibly short space of time.

In conclusion
VISI is an incredible piece of kit. If you just look at the modelling aspects (we’ll get onto the really meaty cutting metal related portion next month), then it’s incredibly powerful. Today’s CAD users are more discerning that ever before. We’re all used to the ability to work quickly and efficiently with geometry, and while the majority are certainly using one of the mainstream midrange modelling tools, when you’re dealing with import data or working with complex surfaces, you’ll quickly run into the one problem those types of systems have (and let’s be clear, I’m talking about SolidWorks, Solid Edge, Inventor et al). Those systems work best with native data, because they’ve been designed as authoring systems with the end goal being a 3D model or a 2D drawing derived from it. A system like VISI (and there are others in the same class) differs in that the end goal is a production model on the back of which machining or tooling design is going to take place. When you focus on the mould and die market, the processes often rely on your ability to analyse, validate and fix the geometry your client provides, then to ensure that you create the best mould tool you can – because production success is directly attributable back to that underlying geometry. While VISI has all of those surface-based modelling tools you’d need, the system also has a massive range of tools that support the entire process, whether that be mould design or electrode extraction and design, as well as supporting the creation of production drawings in a very automated manner. While it’s not recognised as a standalone modelling tool, but as part of a bigger, more fully encompassing offering, I’m pretty damn sure that VISI could take the Pepsi challenge with any other modelling system on the market today – and win.

Part 2 - Manufacturing this time – the stuff I love. While with other vendors and other products, picking out the good bits of a new release might be a fairly easy task, VISI presents me with somewhat of a problem. The long and short of it is that there are a hell of a lot of manufacturing-focused products within its range.

There are the CAM-related functions based on both home-grown NC technology and Vero’s acquisition of NC Graphics’ Machining Strategist some years ago. There’s also mould design, from its traditional stamping ground (excuse the pun) of core and cavity creation, mould base design and now into mould filling simulation with VISI Flow. Then there’s an area that very few vendors touch; progressive die design.

What should be noted is that everything we discuss here is fully integrated into the same environment. The user interface and interaction methods you use to design the parts are exactly the same ones used to program the NC code, generate mould bases and progressive dies and much more. So rather than trying to fit everything into two pages, I’m going to look at the common themes and pick out some of the interesting updates along the way to give you a flavour of what it’s all about, starting with CAM.

VISI Machining
VISI 16 is a landmark release for CAM users as it sees some major changes made to the way users interact with the system. Now, before existing users panic, let’s be clear, this is undoubtedly a good thing. Vero has separated the management of geometry from the machining operations, whereas in previous releases machining operations were inextricably linked to the underlying geometry. This first manifests itself within the UI and users now have separate windows for features and operation. This provides many advantages, including a great deal of preparatory work that can be done to locate and identify the features within the model.

There is also a range of feature recognition technology that allows users to automatically find features such as holes (including bored, sunken and multi-step holes), pockets (open, rectangular, circular, irregular) and bosses (rectangular, circular, irregular, ob-round) and formalise them. These can be arranged, grouped and organised before the programming process is started.

The flexibility of the system means that features can be quickly swapped between different set-ups using drag and drop, ensuring the most efficient angle of cut, without having to bother too much with time consuming set-up work. Importantly, every set-up is validated against the mechanical constraints of the machine tool. If a 3+2 rotation cannot be achieved on the machine, the user is warned and prompted for another solution.

Machining operations are added through the operations window and here the user has access to everything that pertains to the cutting of material. Operations are grouped into the usual categories: 2.5, drilling ops, 3-, 4- and 5-axis cutting and advanced operations such as adaptive clearance and complex surface machining with additional tooling support for undercut machining. Adaptive clearance uses a concept similar to trochoidal milling. This unique cutting technique provides the ability to cut using the full depth of the tool and safely run your machine at the optimum speed. Tool wear is spread evenly across the cutting surfaces and the centre-of-force is half-way up the tool, reducing deflection and the potential for vibration. Adaptive Clearance automatically adjusts the toolpath, improving cutting conditions and allowing higher machining speeds to be maintained.

When it comes to defining the specifics of each operation, existing users will see that there’s been a lot of work done on the operation dialogs to make them both more consistent and easily understandable for the casual or infrequent user. Graphical previews that show how each operation works are used to great effect so it’s pretty clear what you’re working with at any point.

Alongside to the core changes made to how the CAM functions work, the other big news for this VISI release is the introduction of what Vero is referring to as ‘compass technology’. Essentially this is a new method for users to collect sequences of operations that can be applied to common found geometry (using feature recognition).

It’s common to find the same ‘types’ of features cropping up, whether that’s multi-operation holes, pockets or bosses and this allows users to standardise how they treat those forms. They can be built to adapt to the specific geometry in each instance (such as the size or depth of a pocket) to best suit that particular geometry, but retain a standard operation list. This technology is capable of providing complete CAM automation by recognising the characteristics of a feature, selecting a valid operation cycle and automatically adapting the parameters or each operation to better optimise the calculation and result performance based upon the geometry type.

VISI Mould
Mould design is VISI’s bread and butter, there’s no doubt about that whatsoever. This release doesn’t see a huge amount of work done in comparison to other areas of the system (as it has a mature and deep selection of mould design tools already), but there are some updates that are worth covering as they either bring new functionality or add new tools that will make the mould designer’s life easier.

The new Lock Builder application takes advantage of VISI’s parametric engine to automate the creation of both male and female locks in core/cavity models using standard combinations and corner conditions with fully dynamic previews. That parametric base has been also used to make cavity insert design much easier. These are now driven from a simple dialog that allows users to define their exact requirements (in terms of size, shape, corner relief, blending and offsets).

There’s also been work done on the gating/runner and cooling design. The cooling channel design tools have been consolidated into a single command, backed up with a selection of standard cooling components and collision/interference checking. Gates and runners has a few new options with the ability to add cold slug wells, vary the size of gates and to define both the position of gates and injection points and the angle value for each. Importantly, all of this valuable information is automatically passed through to the plastic flow analysis.

The final update is the new ‘exploded manager’ which allows users to define precise assembly layouts of a tool where they can create the assembly sequence of everything within their mould stack and validate it dynamically. While any experienced mould designer worth their salt isn’t going to rely on this (rather working on the back of knowledge and experience), it does make light work of creating assembly views which can be passed downstream for documentation in drawings.

VISI Progress
Without putting too fine a point on it, progressive die design is a black art, but one that can be made much more accessible and perhaps intelligent with the application of technology. When you have a part that’s manufactured in such a serial manner, where each form is built up and added to a strip with each progressive stamp, the process of defining the die set for it is always going to be complex. The good news is that Vero has been working on these problems for many years and this release sees the culmination of that more recent work.

There has been a fundamental change in how the system works with part data to drive the unfolding process. Whereas it previously worked with a neutral-fibre skin calculated from the solid model to create each bend and fold, the system now works with a surface-like skin in conjunction with a FEA engine to drive the ‘neutral-fibre’ of the part.

There are now two distinct approaches to the unfolding process. As in previous releases, you can still use the same history-based method to unfold each feature, each bend. While this gives you benefits in terms of handling design change, it does add an overhead to store that history. However, VISI 16 introduces an offline method of unfolding parts, which is quicker, and in some cases easier, but doesn’t have that history-based benefit.

The new offline tools have been introduced for a couple of reasons, but the primary one is to enable the unfolding and flattening of non-linear bends and flanges – something that’s typically extremely difficult to define digitally. Based upon both automated and user-defined binder surfaces this new method means that there’s now powerful tools to take highly complex stamped parts and sequentially develop them into a workable blank, without the need to manually construct the flattened geometry.

Of course, unfolding the part is just the start of the prog-die process. Once you have your flattened data, you then need to start creating the punch geometry that produces the shape form within the flattened strip. There’s already an extensive set of tools for doing just this, but this release adds a few updates to this area too.

Punches can now be created with notches (of a variety of standard shapes) to add mis-match punch relief. Bend punches can now be extracted directly from the strip surfaces and stored as items in the Strip Tree. There are also new tools to ensure that you’re making the most of your material, with the ability to automatically create and manage mirrored parts as you define the strip. VISI now has a new nesting algorithm which presents multiple layout combinations which will assist the user in selecting the most economical result, minimising scrap wastage.

The systems also includes the ability to create a strip report as a HTML file that contains screenshots of the strip, the punches as well as critical data such as step, width and shearing stress. The final update for VISI Progress I wanted to cover was the spring calculation. As you’d expect, the system allows the user to create the full 3D tool assembly that’s going to manufacture the part, from the punches, through the die set. The system now includes the ability to automatically calculate the spring configuration and layout based upon user defined parameters such as pre-loaded spring length, force and stroke. It links in with standard supplier catalogs and should save a huge amount of work.

Conclusion
I get to visit all the major vendors every couple of months. Some you leave thinking “Ok, good. But where is the innovation?” Others you leave impressed with their dedication to their users and to advancing the use of their products. Vero Software is always of this latter group.

VISI has been an impressive system for many years, but in the last few release cycles the company has really cranked up the development cycle a gear or two. Compared to when I first saw the system, VISI today is supremely impressive. Not only does it have a wealth of knowledge and years of user-led development behind it, but also the work done recently to both refresh the user interface and to introduce new technology. The perfect example of both aspects working in concert are the new automation or intelligence-based tools which capture best practice and standard forms and allow users to create them in a very short space of time (whether that’s cooling channels, mould locks, mould stack design or NC operations).

Taken as a whole, VISI is one of the most impressive products out there for those engaged in manufacturing. It’s got all the 3D CAD tools you could ever need, backed up with some highly impressive mould and die design tools which can then be followed through into production with the NC programming tools that have been its core competency for some time. It proves the fact that general purpose tools sometimes simply don’t cut the mustard and if you want to get the job done, you have to use a tool that’s tailored to the job at hand.

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