The Internet And The Library

“In this digital age, the custodians of published works are at the center of a global copyright controversy that casts them as villains simply for doing their job: letting people borrow books for free.”

(ZDNet quoted by “Publisher’s Lunch on July 13, 2001)

It is amazing that the traditional archivists of human knowledge – the libraries – failed so spectacularly to ride the tiger of the Internet, that epitome and apex of knowledge creation and distribution. At first, libraries, the inertial repositories of printed matter, were overwhelmed by the rapid pace of technology and by the ephemeral and anarchic content it spawned. They were reduced to providing access to dull card catalogues and unimaginative collections of web links. The more daring added online exhibits and digitized collections. A typical library web site is still comprised of static representations of the library’s physical assets and a few quasi-interactive services.

This tendency – by both publishers and libraries – to inadequately and inappropriately pour old wine into new vessels is what caused the recent furor over e-books.

The lending of e-books to patrons appears to be a natural extension of the classical role of libraries: physical book lending. Libraries sought also to extend their archival functions to e-books. But librarians failed to grasp the essential and substantive differences between the two formats. E-books can be easily, stealthily, and cheaply copied, for instance. The source of the e-book – scanned printed titles, or converted digital files – is immaterial and irrelevant. The minute a title becomes an e-book, copyright violations are a real and present danger. Moreover, e-books are not a tangible product. “Lending” an e-book – is tantamount to copying an e-book. In other words, e-books are not books at all. They are software products. Libraries have pioneered digital collections (as they have other information technologies throughout history) and are still the main promoters of e-publishing. But now they are at risk of becoming piracy portals.

Solutions are, appropriately, being borrowed from the software industry. NetLibrary has lately granted multiple user licences to a university library system. Such licences allow for unlimited access and are priced according to the number of the library’s patrons, or the number of its reading devices and terminals. Another possibility is to implement the shareware model – a trial period followed by a purchase option or an expiration, a-la Rosetta’s expiring e-book.

Distributor Baker & Taylor have unveiled at the recent ALA a prototype e-book distribution system jointly developed by ibooks and Digital Owl. It will be sold to libraries by B&T’s Informata division and Reciprocal.

The annual subscription for use of the digital library comprises “a catalog of digital content, brandable pages and web based tools for each participating library to customize for their patrons. Patrons of participating libraries will then be able to browse digital content online, or download and check out the content they are most interested in. Content may be checked out for an extended period of time set by each library, including checking out eBooks from home.” Still, it seems that B&T’s approach is heavily influenced by software licencing (“one copy one use”).

But, there is an underlying, fundamental incompatibility between the Internet and the library. They are competitors. One vitiates the other. Free Internet access and e-book reading devices in libraries notwithstanding – the Internet, unless harnessed and integrated by libraries, threatens their very existence by depriving them of patrons. Libraries, in turn, threaten the budding software industry we, misleadingly, call “e-publishing”.

There are major operational and philosophical differences between physical and virtual libraries. The former are based on the tried and proven technology of print. The latter on the chaos we know as cyberspace and on user-averse technologies developed by geeks and nerds, rather than by marketers, users, and librarians.

Physical libraries enjoy great advantages, not the least being their habit-forming head start (2,500 years of first mover advantage). Libraries are hubs of social interaction and entertainment (the way cinemas used to be). Libraries have catered to users’ reference needs in reference centres for centuries (and, lately, through Selective Dissemination of Information, or SDI). The war is by no means decided. “Progress” may yet consist of the assimilation of hi-tech gadgets by lo-tech libraries. It may turn out to be convergence at its best, as librarians become computer savvy – and computer types create knowledge and disseminate it.

CAD/CAM Software and High Speed Machining

What is CAD/CAM Software?

Computer Aided Design. In reference to software, it is the means of designing and creating geometry and models that can be used in the process of product manufacturing. Computer Aided Manufacturing. In reference to software, it is the means of processing a designed part model, creating machine toolpath for its various components and creating an NC program that is then sent to a CNC Machine tool to be made. The CAD and the CAM are integrated into one system. CAD/CAM software is also highly referred to as CNC Software as well. The heavily searched term, “CNC Software” will also include pc-based cnc controller software as well. This is where you can turn your computer into a controller for your machine that supports up to 6 axis programs. An excellent example of this is Mach 3 controller software provided by ArtSoft.

The purpose of CAD/CAM is to automate and streamline CNC programming allow innovators, designers and CNC businesses to manufacture products, bringing them to market faster and more profitably than ever before. It is the concept of producing goods Faster… Smarter & Easier.

Traditional Offset versus High Speed Toolpaths

The term, “Toolpath” is used to visually display and describe the route in which the CAM side of the software tells the cutting tool to machine the geometric regions of the part model. It’s the path that the tool takes when machining. Toolpath is going to be basically being defined by the part or areas that the user has chosen to machine, the size of the tool being used, the cutting regions for those tools and the type of machining strategy that is used. That is toolpath whether it’s for a mill, router, laser, burning machine, waterjet or cnc lathe. There is a lot of other data that is included in the creation of a NC Program that has to do with post processing parameters such as speeds and feed rates based on strategy, material and tool data and more. Machine controllers can be different in how they want to see the g-code for the program to be read properly by the controller. That is toolpath.

More than one toolpath is typically used to perform machining operations. Generally this will be a “Roughing” and a “Finishing” operation. Roughing is generally the first stage of machining.

This is where multiple step downs by the tool, remove the bulk of the material.

The second operation will be the finishing operation to complete the machining phase. There is also “Semi-Finishing”. An example of this would be the use of a Z-Level Roughing operation to remove the bulk of the material. Then a Z-Level Finishing operation to “semi-finish” the part and lastly a “Equi-Distant Offset contour” operation to finish the part off. By employing the use of High Speed toolpaths into your machining operations you can achieve excellent results faster than by using traditional offset toolpaths. Even in the world of 3D machining. BobCAD-CAM software offers a unique Advanced Roughing operation that includes the option to use an Adaptive High Speed machining technique. This was specifically added to give the programmer an advantage in roughing out 2D or 3D regions of a part, or the entire part.

Boundaries can be created and used to segregate the toolpaths into specific regions of the part, deep cavities or regions that require a smaller tool to machine. This would not be used to replace a REST operation. An advanced REST machining operation would be used as a part of the finishing process to clean up areas where the larger tools were unable to machine. Traditional offset toolpath has been the most common form of toolpath in use since the advent of CAM software. However, as more and more shops begin to use HSM they are trusting it more, becoming less criticaland beginning to enjoy the benefits of it. The goal of using a trochoidal form of machine path is to limit the number of collisions that the cutting edge of the tool has with the material, reducing chip load, better utilize the cutting tool itself by using more of it while taking deeper cut depths and all while at much higher speeds.

There are distinct differences in toolpath operations, planar, offset and high speed (HSM).

Planar (1) is the most fundamental of the three and is basically a back and forth slice across the material. Options for this style of toolpath would include the ability to machine in one direction (zig) and back and forth (zig-zag). You should also be able to determine a cut direction (climb or conventional), determine a “Lace Angle” parameter and a step over for the cutter. Some CAM systems will allow you to include a side allowance and a bottom allowance so that material can be left over for a finish pass. Tool lead-ins and lead-outs will often times be limited to a plunge, ramp or a spiral lead-in when using this type of strategy, each option definable through input parameters. In addition, compensation controls can be available for the finish pass. These options would include the availability of a complete tool database/library with tool crib and tool holder libraries as well as a complete material database/library. CAM software is designed to organize these strategies and associated variables. BobCAD-CAM has developed each machining operation into “wizards” that step the operator through the procedure so that the features are organized and no variable is left behind. This makes the process easy to understand and get through.

In addition, the CAM software allows for the overwriting of system tool parameters so that the experienced operator is not limited. These would include the use, or not, of system tools, tool height and offset values, speeds and feed parameters for the operation. These operations should also allow for the slowing down of the tool when entering an arc corner (when not using HSM).

Offset (2) is most common in cnc machining open or closed wall pockets and slots in a 2D/2.5 Axis (X, Y and Z step down) program. Very similar to planar, this type of operation in a CAM system is going to have the same variable inputs. The difference is whether you want to create an offset IN or an offset OUT. These concentric offsets will either start outside working their way toward the center of the specified cutting area or start in the center and work their way toward the outer wall or defined area.

All of these operations in a CAM program will also include single step or multiple step options. This is where a total depth is either automatically calculated based off of the part model or manually input by the programmer. A depth of cut is entered and the CAM program should automatically calculate the number of Z-Cuts needed to machine (rough) the part region.

The offset toolpath will typically have many right or left turns where there can be a lot of stop and go occurring with the tool while machining. The more times this happens the more wear and tear there will be on the tool. Often times this type of toolpath will produce higher levels of vibration as well and require spending more money on tooling for jobs that have cutter designs that minimize heat in the cutting zone in order to reduce power consumption as well. Offset toolpath can lead to higher rates of tool deflection which can also lead to parts being cut out of tolerance and poor surface finish results. This means that higher speeds and feeds often times cannot be used. While offset toolpath can be very useful, it is the High Speed toolpath strategies that provide the greatest benefit.

High Speed (3) machine toolpath strategies, also known as “Trochoidal” machining toolpaths open the door to a number of important benefits.

  • The controlled arc of engagement generates low cutting forces which enable high axial depths of cut. Multi-edged tools can be used which enable high table feeds with secure tool life. In other words, deeper cuts can be achieved easily.
  • The whole cutting edge length can be utilized ensuring that the heat and wear are uniform and spread out, leading to longer tool life.
  • There is a constant tool engagement, deeper cutting and NO stop and go.
  • High Speed toolpaths are excellent for slotting and pocketing when vibration is a problem.
  • Much higher speeds are used resulting in superior finishes due to a number of factors (reduced tool deflection, vibration/chatter etc.)while machine cycle times are vastly reduced. Shorter cycle times on jobs.

Most shops are cutting faster today than they did ten years ago. Albert Einstein said it first and best, “All motion is relative.” From that perspective, incremental improvements in “rate” mean that a shop is machining at high speeds relative to what it did previously. Increasing the feed rate of a ball-nose end mill in tool steel from 12 to 24 ipm and spindle speed from 4,000 to 8,000 rpm is a 100 percent increase in cutting speed and well within the capability generally found on most CNC machining centers.

In addition, as the cutter creates a chip, the heat generated by that action is transferred to the chip. When the chip breaks and leaves the cutting zone, the heat is carried away with it. A big advantage of high speed machining is that at elevated rates of speed and feed, the chip is cut and evacuated so fast it tends to transfer little or no heat to the green workpiece. In many cases this eliminates the need for coolant. At conventional machining speeds, there is time for heat to move from chip to uncut metal and create a work-hardening condition.

This increases the force needed to create a chip, which creates more heat, and so forth. Coolant mitigates the cycle by reducing the temperature in the cut zone and flushing away the chips. However, at very high rpms, the tool rotation throws coolant away from the cut zone so without very high pressure or through-the-tool piping, it never reaches the cutting zone. Trapped chips can remain in the cut, allowing them to be re-cut by the tool. Therefore, an air blast is very efficient for evacuating chips in high speed applications.

High speed machining can certainly help a shop manufacture more accurate parts with better surface finishes. And often, because a machine tool and workpiece setup has to be very rigid for high speed machining, the results are more consistent workpieces. All of this together amounting to higher efficiency in CNC programs, machining and in the end, increased profitability for a CNC business.

SOME HISTORY…
Years ago, in the beginning of NC, each block of data was executed in order, one at a time. Speeds were sufficiently slow that this was a workable arrangement, especially for drilling and 2D linear milling operations. It was when the machine needed to execute a curve or contour that the need arose for seeing what kind of data was ahead in the program. Otherwise machine momentum would cause the cutter to overshoot or undershoot a programmed change in cutter direction, wreaking havoc on the workpiece. That need lead to the development of look-ahead, which is requisite for high speed machining of any geometry except for linear, single-axis moves. If your CNC controller doesn’t have a look-ahead feature, it needs to be upgraded for high speed machining. In 2013 there are many affordable solutions to this such as Mach3 by Artsoft that can help ramp up those older machines.

Taking The High Speed Route To CNC Profitability
We really do not see a training book that specifically addresses high speed machining and CAD/CAM together. However, CAD/CAM software is an absolute necessity for the creation of these types of machining toolpaths. Without CAD-CAM software they wouldn’t exist today. The benefits listed in this paper outline all of the reasons why shops should take advantage of this technology. And now, high speed adaptive roughing strategies being available through BobCAD-CAM for Multiaxis cnc machining for the first time, opens the door for even more complex cnc work to take advantage of its powerful abilities and profit-building results. Machine time is money and the reduction in cycle times that lead to faster turn-around, happier customers, better finish results, reduced tooling expenses and a longer life for your cnc machine tool all equal profit and better business practices.

Dissertation Help: Why Doctoral Students Should Use Reference Software

Dissertation processes break down when students cannot find, or have poorly organized their reading. Lack of beginning organization will result in loss of time throughout the dissertation process, and time is your most precious commodity throughout graduate school. This article covers the beginning organization of dissertation reading and writing, while focusing on the frequently asked question: “Why should I use reference software?” While EndNote is the software that I use, and therefore know most intimately, any software might work as long as it allows you to do these three things: first, helping you capture and organize your notes, second, allowing you to cite and build a reference list while you write, and third, allowing you to change reference styles easily. All three attributes to good reference software along with brief notes as to how they will help you in your dissertation process, are discussed in this article.

Capturing and Organizing Notes

Beginning doctoral students rarely understand the importance of capturing every little part of their thoughts in a database from the time they begin. The notes you take now,on the ideas you have as you read will become invaluable later. If you don’t start a reference library at the beginning of your process, at some point you will have to back up and capture ideas you have lost. As a secondary student I was brought up in the times when people kept notes on notecards. We were trained to put down the complete reference, and then capture each idea that we found interesting and might use for our writing in the future. That same idea holds today in reference software such as EndNote. You are doing more than capturing that reference and what you read, you are capturing your ideas about it.

Because you’re using a database you will have fields, some of which you may need and some of which you may not need for each particular type of reference. Be sure to fill in each necessary field every time you pick up and read an article you find worthy of note. This can be done by electronic transfer, depending upon your library, from your library database directly to your EndNote file. You also might consider simply typing in the information needed as oftentimes that is faster than electronic transfer. Never leave a reference without capturing notes about your ideas on the article in the lower database fields. Why did you read this article? What did you find important about it? What ideas do you not want to forget? Make sure that all of these questions are answered before you close out of any documentation on your reading.

Citing and Referencing While You Write

Academic work requires that we acknowledge the other authors whose work we have read and who influenced the ideas about which we are writing. This is not the same as quoting them verbatim. I suggest that you start a habit of writing what you think from your own point of view, and then, at the end of each paragraph, going back to your reference list and acknowledging whose work added to what you have just written. If you are using EndNote, and hopefully for other quality reference software, you will be able to highlight the references of the authors you want to cite and easily bring that group citation into your writing. The reference software should also simultaneously start a reference list and keep it alphabetized for you. This step alone saves you hours and hours of work. When you have one author who wrote several things in the same year, the software will even go back and add the requisite a. or b. after those citations.

There are times your references may change a little. For instance you might discover that you had spelled an author’s name wrong, or you somehow needed to update some of the fields in the reference. Rather than having to go back through each document in which you have ever used that citation, you can know that by simply refreshing the reference list when you open the document again the updates will occur. As your academic writing goes on for years, this will save you more time than you can now imagine.

Changing Reference Styles Easily

Your university requires that you use one particular reference style, and to constantly refer to that particular style manual. Your reference software does much of that work for you by maintaining the updates as those style manuals change over time. Keep in mind that you will not always write under the same style because academic journals use several different styles and you have to make your writing match the needs or guidelines of the publications you write for. Once again EndNote, and hopefully other reference software, will allow you to change the style, and then update the document, to reflect that change.

There are other specific reasons once you start writing doctoral dissertation that you will want to have all of the things you have read captured in reference software. As an example, a complete database will allow you to easily sort your reading into topics for your lit review and write each topic area under your own voice. The ways in which you can use reference software during the dissertation or thesis writing process are covered in other articles. Meanwhile, in summary, a beginning doctoral student will save themselves many hours of time by starting early to use reference software to capture and organize their notes, cite and reference what they read while they write, and allow them to change reference styles easily.