Collision Avoidance or Detection? (Part 2)

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 :)

 

 

CNC – Collision avoidance or collision detection?

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.”

Are apps relevant to CADCAM?

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.

 

Clouds and CAD CAM Software – Part 3

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.

 

Clouds and CAD CAM Software – Part 2

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.

 

 

Clouds and CAD CAM software – Part 1

Everyone is talking about the Cloud

If you are reading this blog entry on a desktop computer, notebook, netbook, smart phone, tablet or other form of internet reader, chances are you have not only heard about the “cloud” but used it in one way or another. Many applications for smart phones and tablets store their data in a cloud somewhere. When you download a song that you purchased, you are likely downloading it from a data cloud on the internet.

There are a few uses of the cloud, and we are going to talk about two of them here. Cloud storage and Cloud computing, but first let’s look at some different types of clouds.

Cloud

Cloud Data

Types of Clouds

Just as there are different types of meteorological clouds, there are several different types of data clouds. Corporate Clouds may be data centers built and maintained by one corporation that are only allowed access by people in that same corporation. Personal Clouds may be small clouds set up by yourself only for yourself. Both of those are often referred to as Private Clouds, or clouds designed and maintained for corporate or private use. Public clouds may be companies that provide cloud storage as a service, to almost anyone on the internet. Amazon’s cloud or Apple’s cloud would fit this category.

Cloud Storage

Certainly one of the most common and largest uses of the cloud is for storage. Saving your music, videos, pictures, data or other files onto some storage space somewhere, usually through the internet, other than on the actual computing device (computer, smart phone, tablet, etc)

Apple introduced the iCloud, Amazon has their Cloud Drive, even computer and tablet manufacturers are getting in on the action, such as the ASUS online cloud backup.

Services like these allow you a location, in the cloud, to store files. In many instances, you can access your data directly from the cloud, for example, streaming your music directly from your account in the cloud.

Access and costs to the various cloud storage options are different for every company. Perhaps a small amount of data is free, where one pays a subscription for more data. In other instances, basic cloud storage is included with the purchase of a hardware product.

Some services use the cloud as a way of performing file transfers between different parties, such as Dropbox. Many people use this as the 21st century equivalent of  FTP file transfers of the past.

Cloud data

Multiple Devices & CLoud

Personal Cloud

With today’s technology, you can even make your own cloud. Western Digital’s MyBook Live allows you to buy a device that goes on your personal network, and allows you access to it from anywhere that you have an internet connection, including the ability to stream music, or connect to this personal cloud from smart phones and tablets.

Personal Cloud

Personal Cloud may look this Simple

Cloud Backups

A subset of cloud data storage are cloud backups. Products and services such as Barracuda provide local backups that can also be mirrored onto cloud storage. On a more personal level, products like Carbonite can provide automated backup of your home or small business computer hard disks to the cloud.

Having backups of data in a separate location from your home or office is always a good idea in the event of catastrophic events to your computers (such as fire).

When looking at a cloud storage service you should consider:

  • Will you need to access the data files from different types of devices and operating systems? From Windows computers, Apple computers, smart phones, tablets or even alternative operating systems (Linux)
  • How secure is your data? What security do the cloud services use to keep your data secure and private?
  • Has the Cloud storage had significant downtime? Do they have alternate servers and backups of their own to keep maximize uptime?
  • Do you want to stream music over the cloud? While a great feature, streaming your own music vs listening to it locally will count against any data caps your internet service may have.
  • What are the yearly fees, if any? What extras do the fee based cloud servers provide you that the free versions do not?
  • If performing cloud backups, how easy is it to restore the data should you ever need to?

We have only touched the surface of this topic. In part 2 we will discuss the use of the Cloud in CAD CAM environments.

Do you use a cloud service? What types of devices do you use to access your files on the cloud? Do you use a free cloud or a cloud with a payment or subscription? How did you pick the cloud service you use? Feel free to leave a comment on part 1 of Clouds and CAD CAM software and find out how you use the cloud.

Increasing your CNC Skillset

In the previous blog entry, a guest blogger spoke about overcoming the manufacturing skills gap. One link from Deloitte in particular spoke of the manufacturing jobs available, and the shortage of skilled people for those jobs.

At the macro level, there are many programs and schools available for training and providing skills for workers.

However, at the Micro Level, there are always ways and things an individual worker can do to increase his skill set and become more valuable to the skilled work force. Below are some possible options.

Use the Math

As a machinist, get the Machinist’s handbook and study it. Learn how to calculate common machining equations such as SFPM, surface feet per minute. Learn what chip thinning is, and learn how to apply it to your feedrate calculations.

Try New Technologies

Tooling companies are always introducing new cutting tool shapes, grades and coatings. Ideally, test them out so you can make your employer more competitive. Even if that is not possible, read up on the latest cutting tool technologies and trends, stay familiar with new products, so that you will be perceived as more of an expert by peers and guests.

Try new methods to mill your parts.  Experiment with different algorithms or clean out routines, figure out when one method works better than another solution. This knowledge will always be useful to employers and future employers.

Stay Informed – be recognized

Many people use social media to stay informed in the machining community. Forums are a good place to build community. If you are able to answer questions, or provide solid advice to others in a forum, then in short time you will be considered knowledgeable and an expert in your field.

Use the same social media to stay connected to advanced technologies out there. Things like LinkedIn or Facebook can keep you in the loop of new releases, new products and other news from suppliers.

Read and Challenge Yourself

Being well read on a subject is always beneficial to your career. When doing a new part, that’s similar to a previous part, challenge yourself to do it just a little bit better. Continuous improvement is not only good for the bottom line, but good stimulation for the brain.

That’s what we are looking for

Sescoi is actually hiring, a regional account manager in Michigan. We are looking for someone that has been able to stay current on trends in tooling and software. Someone who is eager to try new technologies. Someone not afraid to challenge themselves. Obviously, we also place high value on people with WorkNC experience, other CAM software experience, as well as sales experience. If you think this could be you, and you meet the requirements listed in the link, then by all means apply at the link above.

 

 

The importance of good CAM technical support

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…..

Training keeps up productivity

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?

Optimizing the post-processed NC code can yield big benefits

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.