CGTech Vericut 7.1
31 January 2012
Process type: Manufacture
We take a look at how CGTech’s Vericut has expanded from its traditional roots and mastered the G-code verification process
The single technology used on a daily basis in the production preparation process is Computer Aided Machining (CAM). There is a wide range of tools available from 2D-based systems for the creation of basic tool-paths, through to 5-cutaxis machine tools that can produce a component in a single set-up at high speeds.
As anyone engaged in this process will know, proving out a set of tool-paths is a nerve wracking experience. And, as the complexity of the parts and the machine tools used to manufacture them increases, so do the headaches. Essentially the user wants to ensure that when cutter hits tool steel, the tool-path is going to work - first time.
This is where CGTech’s Vericut system comes into play. Basically, Vericut offers an environment in which the raw NC-code from the CAM system can be loaded, linked to a physically accurate representation of the machine tool combined with a digital version of the controller in place.
The key here is that, unlike CAM-integrated simulation processes, which can simply carry through any errors in the tool-path, Vericut runs from the output G-code. This means it will detect any issues early on, hopefully preventing the user from hovering over the big red button on that first run.
Digital machine tools
The key factor in setting up a Vericut task is to get the model of the machine tool ready. Having been in the business since 1988, CGTech has modelled hundreds of machine tool brands providing accurate kinematic machine models. Kinematic models demonstrate how the machine operates, from toolholder and machine bed, through to the full casing, tool changers and safety doors.
This means that the user’s NC-code can be verified using the entire model in a very holistic manner. The model engine within Vericut can support highly complex machines, including multiples of 12 axes (six linear and six rotational), turrets, and spindles. In terms of controller support, it ships with a large range of controllers.
If the user has special codes in use on the controllers, such as macros to invoke multiple tasks such as tool change combined with coolant switching, these can be added in.
Another key factor, particularly if looking at very detailed verification, is the ability to accurately simulate the action of the cutter on the material and within the machine tool space. It’s now common to download detailed 3D models of cutters from suppliers which can save a great deal of time particularly when working with insert style models. The fully detailed model isn’t really needed within Vericut, so the system takes that 3D model and creates the revolved form that represents its shape.
Once the machine and controller are set up, the next stage is to bring in the geometry of the part and the G-code. The system supports multiple set-ups in terms of different fixturing strategies of the work-piece, which means that the user can be up and running pretty quickly.
The key focal point for working with the system is the error log and the ability to review any problems found using the NC Program review. This ties together the NC code, the log-file of errors and the graphics window. Selecting an error will switch both other windows to that point in the program - showing the problematic line of code along with the state of the machine and work-piece.
Another key new tool is the Auto-Diff tool. This takes the CAD-based nominal and the resultant cut model and provides a huge range of feedback about the difference between the two.
Of course, it’ll give an idea of where material is remaining or missing, but it’ll also give reports on any gouging. It’ll display the gouged areas on the model, the deviation from the nominal as well as the tool ID that’s involved and the NC lines that are potentially causing it.
The final major update of interest is the introduction of X-Caliper. This allows the user to inspect the in-process model taking measurements such as stock thickness, pocket depths and hole pitches with the aid of cross sectioning if necessary. X-Caliper also provides feature history so that a mouse click will identify feature characteristics as well as the lines of CNC code that produced the feature.
Probing and inspection
This is an interesting one, particularly for those looking at some of the more cutting edge manufacturing technologies now available. Vericut is one of the only verification tools that runs probing and On Machine Verification (OMV) tools properly. OMV is the process of combining a numerically controlled machine tool with an inspection probe, such as the Renishaw devices.
It means that the user can carry out mid-process inspection of components without having to move the component from the shop floor to the inspection room. This saves a great deal of time and hassle. Vericut can pick up and run with the Renishaw code and control the whole process as it would a cutting cycle.
It even has the ability to replicate the ‘sensing’ action of the probe. For example, if using probes to ensure there’s a blank on each position on a tombstone, it can carry out the required actions just as it would in practice. Typically, skip the operations to define that instance of the part in production.
Another example is that if an instance of a part isn’t positioned correctly, it can take measurements and shift the datum of the instance part program so that it machines properly.
Machinists used to working with high-speed machine tools should be aware that fascinating things can be done by varying the feed and speed rates depending on the amount of material that the cutter is engaging with. The new OptiPath tools within Vericut do this automatically.
Given a depth and width of cut, the system calculates the size of chip thickness and optimises the material removal rate. It’ll simulate the new operation, write out a new part program then provide feedback on the original time, the new time and percentage savings.
Tool-paths created this way provide a much cleaner tool path. The load meters on the controller will also show more constant loading, rather than spiking with traditional machining operations. The result is longer cutter life and far less stress on the machine tool itself.
It’s been a good few years since I last looked at Vericut, certainly the first time since we started DEVELOP3D. It’s good to see that the system and the development team behind it are managing the difficult task of staying true to the core tenets of the application by creating rock solid NC-Code, but also finding areas to expand into.
The updates made in the last few releases take Vericut to a new level of completeness and it should give those with highly complex machining programs further peace of mind when verifying those all important operations. Moves like the introduction of OptiPath and providing OMV support show that the system is keeping pace with industry trends and new technologies.
Another new feature in his release is the Vericut Reviewer, which lets the user share the information without the need for a full license. This means that anyone, from management to the team on the shopfloor, can pull up the same data and interact with it.
It’s also worth noting that the CGTech team has been growing the number of systems Vericut can work alongside. There are new interfaces from CGTech that now allow the system to work with GibbsCAM and soon, Esprit.
There are also new interfaces from the CAM vendors, including TopSolidCAM, SolidCAM and InventorCAM, Delcam PowerMill and FeatureCAM, and Open Mind’s Hypermill. To my mind, the system is much more valuable when combined with the tools it has contained for years. So, if you’re in the business of machining complex parts or want to get that cycle time down on parts, then you should be looking to see how Vericut could fit into your workflow and process.