Collision Avoidance or Detection? (Part 2)

May 16, 2012 By jjaje Leave a Comment

Automatic Avoidance is always better than detection.

In the last Blog Post, there was discussion about collision avoidance and detection, especially as automatic avoidance relates to 5-axis machining.

Today we will look at collision avoidance earlier in the process, during roughing.

Difference between Collision Detection and Avoidance.

Collision detection is when your CNC CAM software calculates a cutterpath, which often only takes the tool shape into account, but not the holder or the physical milling machine, then afterwards recheck it for and collisions. If there are any, then manual editing, or some other changes are required to remove the collisions yet still mill the entire part.

Collision Avoidance is when the collisions can be avoided in the first place, during the calculation of the CNC cutterpaths. When roughing, this may include the Tool and Tool Holder, and possibly the spindle.

Mill With the Shortest Tool Possible

You will that mantra from tool vendors all the time, when speaking about performance. Do as much milling with eh shortest tool as possible, and only use a longer tool where necessary, or utilize the short tool at different cutting angles if possible, to maximize performance.

Look at the picture below, in this case we can actually mill out 90% of the material with a very short cutter. We are using the strategy of roughing with a large cutter to take advantage of good material removal rates, and we will use a cutter with a Length/Diameter ratio of 0.9.

Part with tool and holder

Part with tool and holder

In this case, the holder is quite large, so although we can remove the majority of material with this short and sturdy cutter, there will be areas of additional stock to remove.

When you look at the cutterpath from the +Z direction, you can readily see that the CNC CAM  Software automatically limited the cutterpath, taking the tool and holder into consideration, to avoid all collisions, versus just finding collisions after the fact.

Stock Condition after +Z cutterpath

Stock Condition after +Z cutterpath

How the remaining material is removed can be done in multiple ways. Perhaps a different tool or holder from the +Z direction, or if you have the capability to rotate the part, either by a multi axis machine, or simply unbolting it and flipping it on the side, then you can continue to use the same short, sturdy tool to machine the part from other angles, as shown in the picture below.

Roughing with short tool in alternate directions

Roughing with short tool in alternate directions

Other Necessary CAM software Technology

To accomplish multi axis roughing, your CAM software must include the ability to work on a 3D stock model.

To accomplish automatic collision avoidance during roughing, as we did here, then your CAM software must also include the Dynamic Stock Model. Which is a topic for another blog :)

 

 

Filed Under: 5 axis cnc software, CADCAM, CAM software, CAM tips & tricks, NC machining, NC software

CNC – Collision avoidance or collision detection?

April 30, 2012 By cjordan Leave a Comment

For 5-axis applications not only does the CADCAM software have to consider actual collisions with the tool and the tool holder, but also the kinematics of the machine tool itself. For 3-axis machining the concern is mainly the tool length and holder ensuring that it can get into each part of the job without a collision.

For systems with just collision detection, the software tells the user that there is a problem and where the problem is, but the user then has to work out what needs to be done to get over the problem for himself. In some cases this can be very complex and requires detailed investigation of the surface topology of the part.

With CNC software such as WorkNC, users can generate the collided and uncollided toolpaths and get information about the minimum tool length required to finish the job. With this information engineers can cut as much of the part as possible with short rigid cutters and restrict to a minimum, machining with long tools. Best of all, the software does all the calculation for you, so that you can be sure of a reliable, safe and optimized result.

One of the benefits of 5-axis machining is being able to cut much more of the job in one setting with the shortest possible tools, minimizing resetting and secondary operations. If the CAM software just pinpoints where there is a problem, which it will do with collision detection, it is likely that the whole toolpath will need to be recalculated after the problem has been resolved. Producing a useable toolpath this way could take several attempts so at the very least it will be time consuming and tedious. With collision avoidance, the software goes a stage further as it anticipates potential problems as you are programming. Again giving the uncollided toolpath and inserting flip and unwind movements where the axis limits of the machine have been reached.

Having intelligence within the CAM software that provides a solution to potential problems as they occur has got to be a lot better than just letting the user know that a problem exists.

Antonius Köster, who uses WorkNC Auto 5 in Germany, gave this example of one of the problems resolved with collision avoidance. “For an aerospace supplier from the Black Forest, we machined a component which required the tool holder to move inside the part through a drilled hole so that we could mill a pocket at the bottom. Not only was the cutter moving inside the part, but the whole tool holder. This was a really challenging task.”

Filed Under: 5 axis cnc software, Aerospace, CADCAM, CAM software, CAM tips & tricks, NC machining, NC software Tagged With: , , , , , , , ,

Are apps relevant to CADCAM?

April 19, 2012 By cjordan Leave a Comment

Mark Zuckerberg of Facebook has just paid $1 billion for Instagram a small app company that has yet to turn a profit. Facebook is known for its anticipation of web trends and one wonders what this could mean to CADCAM users and if we could learn anything from it.

As the engineering demographic gets younger, the use of smartphones, tablets and social media is bound to increase. Apps let users go directly to the applications they use most and allow them to carry out dedicated tasks without having to search the Web.

Because they are designed to be light and efficient, the speed of operation is much quicker so that you can complete a dedicated task in a much shorter space of time and without the distraction of all the other irrelevant information on the Web. Perhaps Mark Zuckerberg’s vision is that each of us will narrow down our use of the Internet to the topics which interest us and that random surfing from one site to another will become a thing of the past.

Using a bit of imagination about how this might benefit CADCAM users could be very productive. Certainly applications like view mark-up and analysis of CAD data would benefit from this type of approach, and maybe some CAM functionality could be split off into small apps. One possibility might be tool library and tool reordering. You could maintain your tool library in the app, which could be linked to your CAM and ERP system. When you find that a new tool is required, either through a new job or low stock levels, the app could order it from your supplier – just an idea!

Perhaps this type of approach could be a halfway house to cloud computing, which requires very fast broadband speeds to manage the large data files common in CADCAM and without some huge investment in infrastructure is unlikely to be a reality for some time.

 

Filed Under: CADCAM, CAM software, NC software, Other productivity software Tagged With: , , , , , , ,

Clouds and CAD CAM Software – Part 3

April 11, 2012 By jjaje Leave a Comment

During Part 1 and Part 2 of this series, we first looked:

  • What is the “cloud” and what are some different types of clouds, from Corporate and Personal clouds, to Public and Private clouds.
  • One of the biggest uses of the cloud is for data storage, to have access to files or use it to stream music videos
  • Cloud Computing is where your computer is a terminal and the software and calculations you need happen on the cloud servers, we looked at how today, that may not e the best way to perform CAD and CAM.

This week, we wanted to provide some practical tips for the cloud.

Backups – not only should you backup your data files, but also your software configurations. With CAM Software, you should backup things like software .INI configuration files, Post Processors, Custom Documentation, any Custom Scripts, Tool Libraries, Holder Libraries etc.

You should have at least one backup of important data like this off-site, in the unlikely event something happened to the physical location of the CAM workstations. For simplicity, these backups can simply be done on portable hard drives and stored offsite. For a more automatic option, they can be backed up to a cloud storage solution. If using a Corporate Public Cloud for backing up data (ie Amazon cloud, carbonite…) then you can encrypt the data before or as it backs up with a software encryption program, such as TrueCrypt.

Videos / Pictures – Many CNC shops have installed cameras into their milling machines. Those shops using reliable CNC software, such as WorkNC, and performing Lights Out Machining, can look at the status of their mill, in real time, at any time, from virtually any place. While it may be possible to set this up yourself, utilizing a cloud service for this is often easier.

Transferring CAD Data – Years ago, FTP or File Transfer Protocol, was a common way of transferring files between companies. Now, this can be done via a Cloud service such as DropBox. One tip is to compress the files into a .ZIP or .RAR file before sending the files. When doing the compression, you can apply a password to the file, which would be required to un-compress the files.

Sescoi has had the privileged of being invited to and attending COFES (Congress on the Future of Engineering Software). As one of the few companies there with a strong CAM focus, we are always interested in seeing what the general current trends are, and thoughts about the future of CAD and how it relates to CAM. Looking at the breakout technical sessions possible, it is clear that Cloud Computing is taking a larger role than ever before. We are looking forward to getting other feedback from industry peers on their thoughts on the Cloud and Cloud Computing.

What are some uses for the Cloud that you have come up with?Share them with a comment.

 

Filed Under: CADCAM, CAM software Tagged With: ,

Clouds and CAD CAM Software – Part 2

April 5, 2012 By jjaje 4 Comments

In Part 1, we examined what the “cloud” is, and one of its biggest uses, as cloud storage. This week we will examine Cloud Computing and how it relates to CAD & CAM software. First, let’s look at how things have come full circle.

Ye Olde Mainframe

While I may be dating myself with this statement, but one of the first CAD workstations I used was actually not really a workstation. It was a graphics terminal, hooked up to a mainframe computer. The actual computer was behind some locked doors in some windowless room, while CAD operators accessed the computer via a terminal. In this case, it was a graphics terminal, rather than a text only terminal, so that one could see the CAD graphics.

Calculations were not performed on the terminal, but rather on the mainframe in the other room. Data files were stored there too.

Typical manframe and graphics terminal

Mainframe and Graphics Terminal

Workstations Ahoy!

Eventually, workstations began to replace mainframes and graphics terminals. Dedicated Unix workstations could perform CAD CAM calculations faster, with greatly enhanced graphics capabilities, all for a lower overall cost. Graphics calculations as well as the necessary CAD and CAM calculations were all done locally, on the workstation’s CPU. Files may have been stored locally or on a file server elsewhere.

Eventually Windows PC based workstations became powerful enough in both CPU calculations and graphics capability to replace most Unix workstations in the CAD CAM fields.

Unix and PC based workstations

Unix and Windows PC based workstations

Cloud Computing

So then, cloud computing is kind of going back to the graphics terminal, centralized calculation model of the mainframe example above. Calculations are done on the computers in the cloud, files are stored in the cloud. Your computer acts as a graphics terminal to view and use the data. Often, your internet browser is used as the interface for your program running in the cloud.

For many applications, this model may work fine, but how well does it work for CAD and CAM today? To answer that question, let’s look to a popular cloud based graphics application, Google Earth. This is a wonderful product that is very fun to use. For a product like this, cloud usage for data makes perfect sense, as it would take too much storage space, approximately 70 terabytes,  to store all of the images for the whole planet that Google stores.

However, if you’ve used Google Earth, you’ve probably seen images like the one below: This is where the terminal, your computer, is waiting on data from the cloud, Google, before showing you the final image.

Blurry Google Earth waiting for more data

Blurry Google Earth waiting for more data

Imagine this happening with your large CAD part all the time. Waiting for the image to get clear. Now you understand why, for the time being at least, advanced CAD CAM products that are CPU and graphically intensive would not yet utilize cloud computing.

Even a medium sized (36 inches) but fairly complex mold like the one below can require over 3 gigabytes of data when you consider stock model conditions, dozens of cutterpaths, actual B-Rep data, tessellated data for display purposes, etc. Even with a very fast internet connection, there would be considerable delay if all of the computing and data information came from the cloud.

Medium sized mold

Medium sized mold

 

Today, it would be difficult to perform complex CAD and CAM on large parts via cloud computing. This is not to say that in the future, things won’t be different. The one thing we can rely on is change! What are some current uses of CAD CAM and the Cloud that you can think of? DO you see Cloud Computing becoming important in CAD CAM? Leave a comment below.

 

 

Filed Under: CADCAM, CAM software, CAM tips & tricks, Other productivity software

The importance of good CAM technical support

February 28, 2012 By cjordan Leave a Comment

Have you ever bought a piece of flat pack furniture and found that there are a few special screws missing? First, you ring up the store and if you are lucky they answer the phone. Next, you talk to someone who clearly knows nothing about furniture and is not really interested in your problem. Finally, you give up and go to the hardware store or rummage in the garage until you find something which will just about do the job!

Imagine if that was your CAM supplier and your machine was stopped and your customer was on the phone – I think I can safely say that this would be classified as a bad day at work and you would probably need a few beers to get over it!

So, getting good support for your CAM system has got to be pretty much top of the list. What you need is a company that is available when you need it, knows what they are talking about, understands your business and your machines and which is enthusiastic about providing a solution. Lots of tools are available now so that support engineers can operate your PC for you, enabling a solution to be achieved in a few minutes. Where this is not possible, you need the engineer to understand the software and the problem so that a viable workaround can be implemented. In most cases, time is of the essence, so this type of quick response can make all the difference.

For customers using the distribution channel for a CAM product rather than the software developer, the local dealer’s knowledge of the system and your application is paramount. Good CAM vendors will make sure that their dealer channel is properly trained, has fast access to extra help for the more difficult problems, and that it can talk knowledgably about local machining techniques in the customer’s own language.

The best CAM vendors will also involve customers in the development process, listen to their requirements and, either create a special application, help them to implement advanced features in the system, or add new functionality into the next software release. Perhaps furniture shops could learn a thing or two…..

Filed Under: CADCAM, CAM software, CAM tips & tricks, NC machining Tagged With: , , , , , ,

Training keeps up productivity

February 8, 2012 By cjordan 1 Comment

To get the best from your CAM system it pays to take the trouble to do the training courses. Some CAM systems are virtually automatic and intuitive, so the training requirement is quite low and users can start producing CNC programs very quickly and easily.

However, every system has its extras that take a little more effort, but which can make a big difference to productivity. Batch processing of programs overnight, setting up sets of standard machining strategies for different types of component, implementation of feature recognition, and analysis of the CAD data to find draft angles and the smallest radius are just a few of the features available in some CAM systems that can produce big benefits. Although not difficult to set up and use, these types of advanced features can be quickly learnt on a training course, saving hours of trial and error experimentation.

Most CAM systems are being continually developed (if yours isn’t you need to look for a new one!) so extra training in the new developments makes sure that your company is taking full advantage of the improvements, helping it to stay at the leading edge in its field. Furthermore, continuous training helps to build up a closer relationship with your CAM supplier, enabling it to develop solutions to your individual problems and to ensure that you are using the existing capabilities in the software to your best advantage.

Successful companies work in partnership with their customers and suppliers so that they can offer a superior service and product. Close collaboration on both sides significantly improves the performance of both parties. Taking advantage of continual training opportunities raises skill levels and productivity making it a very important part of the relationship.

So, when’s the last time you took update training for the CAM system you use?

Filed Under: 5 axis cnc software, CADCAM, CAM software, CAM tips & tricks, NC machining Tagged With: , , , , , ,

Software Maintenance – reasons to stay current

January 18, 2012 By jjaje 2 Comments

Today we are having some fun with our blog. We are actually going to have two firsts in it.One is commenting on the topic of software maintenance, and the other is to actually reference one of our competitors. The topic of software maintenance often bring up a lot of discussion on various forums, and we welcome your comments also.

What is CAD CAM Software Maintenance & Subscriptions?

Software maintenance is simply paying a set fee, yearly, to receive updates, upgrades and usually technical support for the software product. Software subscriptions, on the other hand, are a form of renting the software product for a set period of time, and then the product “times out” and is no longer available for use, without re-renting the product.

If one does not pay their maintenance, they are stuck with the version of software they had when maintenance ceased, but can still us that version. If one does not pay a subscription, the software stops working after a period of time.

Three Reasons to Maintain your CAD CAM System (from MasterCAM)

MasterCAM software may be a competitor to WorkNC, however, a previous article, published in Moldmaking Technology magazine and on their web page in November of 2010, was written by Steve Bertrand from CNC Software. This article, linked here Three Reasons to Maintain your CAD/CAM System makes some good points. Rather than quote the whole article, I will list his three main points below:

  • Take Advantage of the latest technology – This is absolutely true, as new version of software introduce new features, often geared at increasing productivity and efficiency.
  • Make budget planning smoother – because software maintenance is a known yearly cost, it can be budgeted easier than budgeting for purchased upgrades
  • Help improve the software – People on maintenance often provide the best feedback on new features and functions they would like to see in the software.

To Steve’s listed reasons I would like to add a few of my own.

Support – WorkNC users on maintenance in the U.S. receive phone and digital technical support. We strive to to have live persons available during regular business hours instead of  utilizing voice mail purgatory. Email, file uploads and other digital forms of technical support are also available.

We have found this is the quickest way for customers to get an answer to something, and continue their job. Need a quick configuration change, or a modification to a post processor, it is a simple process.

Increased Productivity – When comparing current versions of CAM software to past versions, users can be more productive now than ever before. New functions like WorkNC’s Multi-Threading and Parallel Processing have cut calculation times dramatically.

New functions can increase productivity, for example, Feature Recognition cut the time to drill holes for some people from an hour or more to two minutes. Other functions, like rib machining or electrode machining can reduce programming time by 90% or more from traditional methods.

Increased Safety – As processing power in computers increases, CAM software developers are able to do more advanced calculations. WorkNC has had tool holder collision checking for a long time now, providing additional safety from early CAM systems. Now, it’s not just collision checking, but automatic collision avoidance with the tool holder and spindle that allows for confident lights out machining.

Remaining on maintenance allows you to receive the latest software versions, to receive the increased efficiency and the increased safety from newer versions.

What are your feelings on Software Maintenance? Is your preference for paid upgrades, yearly maintenance or yearly subscriptions? Leave your comments below.

 

Filed Under: CAM software, NC software

Optimizing the post-processed NC code can yield big benefits

January 11, 2012 By cjordan 2 Comments

nc speed toolpath optimization with worknc cadcam I am sure that every CNC machinist would like to chop a further 20% off their cycle times. Well with toolpath optimization you can!

Toolpath optimization programs which sit inside the CAM system and work on the actual post-processed code, which is the ultimate way of making sure that the machine is running at maximum efficiency, can achieve this sort of productivity boost.   The technology uses volumetric analysis to dynamically calculate the amount of material being removed at any instant. That way it knows the load on the cutter throughout the machining cycle and adjusts the feeds and speeds to keep it steady and within the limitations of the cutter. 

Not only does this speed up machining where cutting conditions are good, but for small tools it greatly reduces the chance of a tool shattering when subjected to a sudden shock load. For the engineer, going faster where possible can produce a big reduction in cycle times, while going slower where machining conditions are challenging, increases tool life and eliminates the possibility of tool chatter which will, in turn, make the tooling itself last even longer. 

As well as saving on the cost of excessively worn or broken tooling, toolpath optimization can reduce the chances of producing scrap and also greatly improve the quality of the surface finish. Vibration from toolpath chatter will damage the machine tool itself, and will also adversely affect the finished component through ripples on the surface. 

The optimization process does not stop when the tool is out of the job. By looking at rapid movements and their physical relationship to the job, the system can ensure rapid moves are used whenever the tool is above the workpiece reducing cycle times even more. 

A further advantage of keeping cutter loads constant is that tool deflection is kept to a minimum. The resulting increase in accuracy will make it much easier to produce very high precision parts.

Filed Under: CADCAM, CAM software, NC machining, NC software, Other productivity software Tagged With: , , , , , , , , , ,

Standardizing on CAD & CAM

January 5, 2012 By jjaje 3 Comments

Integrated CAD and CAM – CADCAM

Previously blog entries from 2010 discussed integrated CAD CAM, part 1 can part 2 can be found at the corresponding links.

Some people mistakenly think that this means the CAM package has no CAD functionality at all. However, this is not the case, and perhaps a better way to phrase the term is Standardized CADCAM rather than Integrated CADCAM.

Integrated CADCAM simply means that the CAM system also has enough CAD functions to create and edit part geometry. From a CAM software perspective, having integrated CAD functions is a necessity, sometimes the CAD functionality is used for regular tasks such as creating boundaries, filling holes or making some “run off” geometry. Specialized CAD functions can actually assist CAM programming, and are often not found in general CAD packages, such as automatic electrode extraction and creation, or automatic core/cavity separation.

Standardized CADCAM

Standardized CADCAM is simply when a company standardizes on one package for all of their CAD and CAM needs. Often this is done to save on up front costs, reduce training on multiple software packages and for a perception that having everything in one package is a better solution.

Very large corporations may standardize on one CAD package. Usually the CAD design functionality, assembly modeling capabilities and PLM functionality overshadows the CAM necessities. Although these companies know they could choose a standalone CAM package, and be more productive in their CAM programming, they often are forced to go with the standardized package. After all, seats with CAM at these corporations may be only 5% of the total seat count, or less.

The 100 million Dollar Switch

All of this brings me to my main point. Without naming companies or contacts, there is a very large company which is switching from one main CAD product to a different one. This is mainly due to the fact that their new owners use the other package.

Switching CAD platforms at this level can take years, and involves many people. Usually it is rolled out for new design platforms are started and as older platforms are retires, the older system is slowly removed from service.

Switching also involves a lot of costs, first is the software cost, and then there are several service related costs, which can include: training, testing, writing post processors, re-writing customizations, re-writing scripts and much more.

It is estimated that the service costs, not software costs, to switch just the CAM departments will be over 100 million U.S. dollars. What could you do with 100 million dollars?

If they had not insisted on a standardized solution for their CAM, they would incur no costs when the CAD system changes. All post processors would already exist, all testing would already have been done, users would already be trained, and they could have been more productive all along.

So the two main points are:

(1) Choosing the term Standardized CADCAM may be a better choice than Integrated CADCAM

(2) Standardizing on a CAM solution because of your CAD/PLM solution may not be (and rarely is) the best or most cost efficient choice.

Are you forced to use a particular CAM product because of corporate standardization of CAD? If so, let us know your thoughts in the comments below.

 

Filed Under: Automotive, CADCAM, CAM software Tagged With: , ,
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