CIM Solutions on advancements in manufacturing and machine tool technology
CIM Solutions on advancements in manufacturing and machine tool technology:
The only thing that will never change is change itself. This has never been so true than in manufacturing industry. The technology of manufacture has become so advanced that process’s that used to take weeks can now be done in hours, and components that used to need 2, 3 or sometimes more machine tools to complete them are now fully machined from start to finish on a single machine with only one setup required.
What’s more the machine tools have become steadily more affordable as more companies realise their usefulness and how easily they reduce manufacturing costs and directly affect the bottom line. This has led to larger volume and in turn cheaper prices.
5-axis machining centres are a good example. Only 10 years ago there were probably only a handful in the country and their price tag was in the millions, but now almost all large toolrooms and many small to medium sized companies have at least one and they can be bought for a fraction of their original cost.
But all of these machine tools are CNC, they have to be in order to do achieve what they do, but what about cad/cam software? Is it keeping up? Can you still use the same software from 10 or even 5 years ago to run these machines?
We the answer is of course no, you cannot. In many cases it has highlighted the outdated nature of some software’s core processing methods; do not forget that many of these products have been around mostly unchanged in their core structure for 25 years or more. Modern machine tools such as the ones mentioned are capable of working on multiple sides of a component without resetting and controlling as many as 14 or 15 axis and up to 6 of them simultaneously. Obviously when development of these products began this kind of capability was never envisaged.
To be able to work with confidence with these machines, modern software must allow the user to model the machines themselves and the workholding fixtures accurately and then to faithfully replicate axis movements exactly as they will occur on the shop floor.
The new software takes the form of a single totally integrated 3D CAD and CAM system, which allows the user to not only model complex components in either solids, surfaces or both but also to machine the parts on any form of machine tool no matter how complex it may be.
The CAD capabilities are totally mainstream and are not limited to single components; CAD capabilities can model assemblies, do mechanical simulations and is fully parametric. CAD capabilities have optional extensions, which encompass mould design, stamping/progression tool design and even sheetmetal design.
Without leaving the CAD environment the user can then place the part onto a machine tool (either in a vice, chuck or on a fixture) and begin machining in a complete simulated environment with full collision checking. The user works directly on the 3D model itself and of course, if the model needs to change then the toolpaths will update themselves.
True integration is the only way forward
Obviously a completely integrated package from one developer means that the part, the tool, the drawings and the machining are all linked, all of the time, so changes and improvements are handled with ease. And of course, you only need to learn how to use one package not 2 or 3 separate ones.
To fully understand the benefits of a complete one-package solution we need to see what happens when we explore the alternative, that is to use a number of separate packages from different developers and trying to get them to work so called seamlessly together.
Interfacing
Whenever 2 or more software packages need to communicate there is always room for error. Sometimes it may be a minor problem but often the problem will be more severe. Each software supplier writes their own code to handle complex geometry. If there are any differences in the way one or the other describes a lofted surface for example, it means you will not get exactly the same shape as was intended. With an integrated product with both CAD and CAM there is absolutely no possibility of transfer errors.
Data loss
In TopSolid for example you may add numerous forms of additional information onto your part models. This can include tolerances, surface finish requirements, machining methods etc. All of this information can be automatically read by TopSolid CAM, of course when transferring model data between 2 separate products this information is lost.
Version lag
This is a very common problem and it happens when one of your software suppliers releases a new version of its software, of course this means that your other package is now incompatible and will no longer work! You cannot afford to lose half of your capability so you simply have to put the new version back on the shelf until the second supplier catches up.
Fragmented support
As long as you have 2 or more suppliers then each of them are free to play the blame game when something goes wrong. Is it the cad’s fault or the cam’s fault? Another aspect of this problem is what happens when you find a bug in the software. If it’s a bug that impacts both packages, you have twice the workload in reporting and monitoring the result. Also if one supplier does indeed isolate a problem in the others software, they cannot fix it they can only report it while you wait and wait.
Future direction – no control
As each software company develops it products, they do so to suite their own goals and requirements. Ultimately this could affect the level of compatibility with other systems.
Why do we need CAD and CAM together?
Realistically these days when we talk about CAD, we are actually talking about 3D models not 2D drawings, and many stand-alone CAM products on the market are simply not capable of mainstream design and modeling. At best they produce acceptable 2D drawings and simple model geometry for machining purposes but that’s all. A full featured mainstream 3D modeler can work in both solids and surfaces, work with single parts and assemblies and automatically produce associated 2D drawings and many of them offer advanced capabilities such as mechanical simulation, analysis etc.
The real benefit of having these capabilities alongside your CAM system is that it gives you the user, complete control over the whole process. You can work from paper drawings or from 3D models but of course we all know that manufacturing is all about changes and with a completely integrated solution you can adapt to changes easily and the toolpaths will automatically adapt themselves.
Another major benefit highlighted by some of the customers is the ability to design work holding fixtures on the fly. Once they have specifies what the raw material will look like they then use the CAD system to model any special jigs etc that are required. TopSolid comes complete with a fully configured library of 3D parts including cap screws, nuts bolts etc and as the user does not have to switch from CAD to CAM he is free to design any time he needs to.
In 5-axis work it is essential to have every aspect of the machine tool and work holding environment accurately modeled if you are to avoid collisions and in a true 3D modeller, this is a relatively simple process and once again as the user is in a single integrated environment these items are visible at all times and the system can warn the user of any impending problems.
Also bear in mind that having a single integrated CAD and CAM system also means you ever have to say No. Whatever your customer asks you to do, you can do it.
In many cases, the users have gone ahead and bought separate programs simply because they did not know that products like the TopSolid range were available, and in a number of cases they have avoided the evaluation process by simply going the same route as a colleague or supplier. Another major misconception is that integrated software is enormously expensive and out of their price range, this is simply not the case as our integrated package is priced on a par with almost all the stand-alone CAD and CAM products currently on the market and therefore provides exceptional value for money.
Specialist products for specialist tasks
There will always be a need for dedicated stand-alone products as many companies would have already made their choice for a particular CAD system for instance and are happy with it. Alternatively we have clients whose business is purely machining and do no design whatsoever. In either case they look for a CAM package that offers the most suitable features for the type of work they do. Contrary to popular belief all CAM packages are not equal and the quality of your work will be directly affected by poorly calculated toolpaths or even worse a gouged component.
Another good example would be dedicated toolrooms who concentrate solely on the 3D machining of complex mould tools. In almost all cases the geometry of these tools will be provided by the client and so in this case we need a software package which can accept CAD data in almost any form, especially in a native form i.e. without using a 3rd party translator like IGES or STEP etc. This greatly reduces the risks of corrupt or misrepresented geometry.
A product such as WorkNC for example can apply roughing and finishing toolpaths onto a model regardless of its complexity or physical size in an almost totally automatic way. The user simply tells the software which tools to use and which toolpaths to apply and the software does the rest. In many cases users of a system like this gain such high levels of confidence that they are happy to allow their machines to run unattended overnight or over weekends.
What to look for, what are the essentials
The evolution of the machine tool industry into combination machines and the increasing affordability of 5-axis has been discussed, so it is important to try to look ahead when making an investment in software. So when we hear people say we do not do that so we do not need that feature only to realize that once you have such a powerful tool in your workshop you can widen your capabilities.
Versatility should be your number one consideration when evaluating Cad/Cam software. In the same way that machine tool prices have been steadily dropping then so has the software. It simply does not make sense to invest in a product that will only cover you for your present day requirements when for the same money you can buy a package with capabilities extending far into the future no matter what the machine tool industry comes up with, and whatever your clients ask you to do.
Constant 3D stock monitoring is essential if you want to minimize air cutting. Software like our always knows exactly what the stock looks like and so makes intelligent decisions when roughing and finishing ensuring that it only cuts where its needed.
Modern software should have the ability to learn from you, in other words, retain knowledge for re-use. Especially if your business tends to do work of a similar nature but from a number of different clients. It is a huge time and cost saver if you can store away a pre-determined set of machining processes and simply re-apply them to a new component. Even if there are a number of small modifications to be made it’s still a lot quicker than starting over each time.
Feature recognition is a major time saver when programming. This is the ability to recognise features such as drilled, reamed and tapped holes, pockets, faces and bosses etc and to know exactly how you want to machine them and what tools to use etc. and make sure that any product under consideration can recognise these features on imported parts as well as native ones.
Look for a true CAD capability, not just simple part modeling. Make sure you get complete solids and surface capability with assemblies and mechanical simulation. Automatic 2D drawing production is 100% associative and a huge timesaver.
Accurate machine tool simulation ensures the user always has a complete picture of the entire process including vices, fixtures and clamps etc, but in many cases these extra graphics can slow the software down dramatically. Make sure that you can work in a fully simulated environment without a performance penalty.
5-axis machining has many benefits, one of which is the ability to reduce or eliminate the use of long tools. A major feature to look out for is the capability to automatically convert 3-axis toolpaths into 5-axis toolpaths. This makes the whole process of working in 5-axis extremely simple because the software will calculate how far over it can tilt the spindle without causing a collision. Using this technology we have clients reporting a reduction from a required tool length of 105mm being reduced to 35mm. If you currently do not have 5-axis machines then look for the ability to automatically split a tool path dependent on tool length. This will allow you to use more suitable machining methods for the longer tools.
Finally consider the quality of the support you can expect after the sale. Sad to say that in far too many cases CAM support is done by CAD specialists most of whom have never set foot on a shop floor let alone operated or programmed any form of CNC machine tool.
6-Feb-2007