InventorCAM
Published Sat 19 Apr 2008
InventorCAM is a brand new fully integrated CAM solution for Inventor users writes Al Dean
Handling design change
In these days of ultra compressed time to market or time to manufacture, the ability to handle design change efficiently is critical. When you’re defining machining operations, you’re creating links between the Inventor geometry and the operation’s parameters. So when you load your tool-paths back up, even if the source design data has changed those links can be maintained.
If you’ve made basic geometry changes (dimensions etc) then the system can flag the change and it can be updated automatically. However, this can become even more powerful with the concept of adaptive geometry inside Inventor. As your adaptive geometry changes inside Inventor then the machining operations can automatically adapt at the same time.
Finally, if you make heavy topology changes where data is removed or added, then the system flags the change and the broken link and allows you to redefine geometry selections and parameters where needed, in a very short space of time.
InventorCAM was unveiled to the public in December last year and now whenever Autodesk demonstrates its new found focus on manufacturing, InventorCAM is the chosen partner. The product has been developed by SolidCAM, a company with a heritage in CAD-integrated manufacturing technology. It’s fully integrated into Inventor and takes advantage of the intelligence that you can build into your Inventor product data models from the outset.
The product supports the full suite of machining operations and technology, from basic 2.5-axis through 3-axis and into high-speed machining and 4- and 5-axis. It also supports Wire EDM, turning and the increasingly popular Mill/Turn combination. InventorCAM is fully integrated into the heart of Inventor and that means directly into the UI, rather than loading your product data into a separate window.
The InventorCAM pull-down menu provides access to the system’s parameters and set-up options. However, the majority of interaction is driven through a new panel which appears where you’d usually find the part feature and assembly trees. From here, users have access to the full range of options, operations, and functionality it provides. So, to see how it works, let’s step through a basic workflow example.
Tutorial 1
Click the thumbnail to view the tutorial. You can navigate through the steps by clicking on the left and right sides of the expanded image or by using the arrow keys.
Tutorial 2
Click the thumbnail to view the tutorial. You can navigate through the steps by clicking on the left and right sides of the expanded image or by using the arrow keys.
As with any NC programming job the starting point is to define the data you’re working with. In the case of CAM, this is predominately centred on the geometry of the part and the machine tool. The machine tool and material definitions are extracted from a standard, but customisable, library. These include the relevant feeds/speeds, movement options, and post processor details. You then define the part geometry based on your native Inventor model and you also need to define the stock from which it’s machined. This could be a simple bounding box which can be dialled in manually or automatically created around the part. (N.B. at all times users have access to the Inventor measuring tools without having to quit the current dialog). It could also be another Inventor part representing a casting or forging with machining allowances, an assembly (with jigs and fixtures) or could be created from a laser scanned model of a casting.
The next step is to define the datum, an extremely important part of the process. It is common to receive parts from clients/suppliers which are not in the optimum orientation for machining. InventorCAM allows you to transform the co-ordinate system/datum, while not changing the original part’s datum. For those working within the aerospace or automotive industry, this is a key capability. It’s also worth noting that InventorCAM only adds a single toolbar, which gives you standard views that relate to this new orientation, rather than the standard Inventor views (front, side, iso etc), so you can view the part using the machining orientation, eliminating any confusion.
The final set-up stage is to define your cutter. Again this is database-driven and you have ready access to an extensive library of standard cutters, but InventorCAM can also connect to third-party libraries or tool management systems from your cutter supplier, usually at no cost. Once done, you’re ready to start creating machining operations – the fun bit.
InventorCAM supports the full suite of machining operations, your choice of which depends on the machine tools you have in house. All operations and strategies – whether that’s 2.5 or 5-axis – are driven from common dialogs, with the same inputs and workflow. However, each is adapted so whatever type of operation you’re programming, you are immediately aware of where to start and what to do.
The first step is to define the Geometry and you do this by right clicking on the geometry branch of the machining tree. You are presented with a clear dialog that shows exactly which information you need to provide, with graphical feedback at all times to show where information is needed or missing. As InventorCAM is fully integrated in Inventor, most of the information is derived from that CAD data. In the case of a basic pocketing operation you start by defining the boundaries by selecting the pocket edges. You then define the upper and lower depths by selecting from the Inventor model and these pay dividends later on as they remain associative to the geometry.
What’s interesting about the system is that it does not force you to use the preset options, and at any time you can add offsets and dial in specific values where needed. The Inventor model geometry is only used where appropriate. Once the geometry is selected, you define the cutter tool. The basic tool-path is displayed instantly to give you an idea of what you’re working with and it’s then a case of optimising it to ensure you get the results you want. If you’re working with High-Speed Machining, then you can switch on the options for ramped entry, helical or radial leads and links. These are also intelligent, and are aware of both the conditions you’re cutting and the cutter itself. For example, if you’re using a large cutter to rough out a pocket, the system adapts the tool-path to fit it where it can, but keeps out of unreachable areas for a subsequent operation with a smaller cutter.
Hole recognition
Drilling holes is a pain in the backside, there’s no two ways about it. You have common forms, all pecked, drilled, reamed and threaded using standard forms, but if you need to program each manually, it can be a very time consuming and laborious task. InventorCAM features intelligent Hole Recognition tools which will find all holes in your part, irrespective of alignment. If the machine supports the orientation and set-up, it will add them to the feature list; if not, it will discard them and save them as Incompatible features which can then be reused in a different set-up. The system analyses each hole to find the elements that make it up and groups the holes into common forms (saving your programming time) – and it can handle some complex forms, with 10 to 12 stage holes presenting no problem. It then selects the tools it has access to, but if a suitable one isn’t found, it’ll flag it up for manual assignment. Once done, it adds the operations required to make each hole to the operation list. What’s interesting is that if your parts are Inventor-native, it’ll pick up the threading information from the hole features, but if you don’t use that functionality for some reason, or are working with imported data, the system again flags it up as incomplete and asks you to assign the threading information.
The next stage is simulation. This is powered by MachineWorks, one of the standard material removal simulation libraries. For the latest release SolidCAM has introduced full machine simulation, which allows you to simulate the movement of an entire machine tool if needs be. For those working with complex mill/turn and 5-axis machining, this means you can get a solid understanding of how your machine moves and full collision detection. Once you are happy with your tool-path, you can then move onto the next feature, and this is where InventorCAM excels.
Within single parts (or a range of parts) it’s common to find features that always need to be machined in the same manner. InventorCAM allows you to take an operation, save & copy it and apply it to another part. You can also save it as an explicit template. In relation to rest machining, where there’s remaining material, you save & copy the tool-path, swap to a smaller cutter diameter and apply the tool-path to a recursive stock model to remove that remainder – which massively reduces any fresh air cutting.
In conclusion
InventorCAM is an impressive fully featured CAM product. It supports the majority of machining processes and specific strategies, from basic 2.5-axis right through to 5-axis and optimisation of multi-spindle mill/turn machines – but then so do many other CAM applications. What sets InventorCAM apart is the integration with Inventor. It follows many of the concepts built into the host system and lets you capture knowledge at a very core level. The ability to reuse data both within a single machining job, and other files using templates, means that you can get your machining operation programmed in a very short space of time and if used correctly, done using your own best practices and commonly used, proven cutting cycles. And as Inventor geometry is linked to tool-path definition at a very core level design changes can be made easily.
