Terranic Systems Inc.

Lean Manufacturing: Liberate Your Machining Processes

noreply@blogger.com (Terranic Systems Inc.) — Tue, 27 Mar 2012 16:32:00 +0000

Lean manufacturing is the answer for companies to stay profitable in today's competitive market. Tool paths are are at the heart of any manufacturing company with a tremendous amount of opportunity hidden in them, which can be tapped with correct digital tools. Read the following feature story to learn more about what you can do to maximize your productivity with little investment

Feature Story: Liberate Your Machining Processes

Uniting Forces for Blade Machining

noreply@blogger.com (Terranic Systems Inc.) — Fri, 30 Dec 2011 21:56:00 +0000

In the recent years, 4-axis blade machining has started to be replaced more and more by continuous 5-axis machining. 5-axis machines allow maximum flexibility and versatility which significantly increase the functionality of standard cutting tools, and reduce the need for multiple set-ups.

Sandvik Coromant's Application Development team devises new cutting strategies to demonstrate how standard tools can be better used to improve production of blades, and CoroMill 390 long edge cutter is one of them. At roughing stage of blade machining, Coromant has achieved high material removal rates using CoroMill 390 without jeopardizing part quality. Working along side with Coromant, we improved the process further using MACHpro Virtual Machining software. The result was a staggering productivity increase of 50%. Using MACHpro, inefficient feed rates along 5-axis tool path due to varying part geometry have been optimized to boost material removal rates while avoiding tool overloads. The short video below is a snippet of the optimized blade machining and shows how optimized feed rates have been executed on the machine.

Improved Positional Five Axis Machining with NC Program Optimization

noreply@blogger.com (Terranic Systems Inc.) — Mon, 15 Aug 2011 09:22:00 +0000

Background
Positional Five Axis Machining refers to 3-axis machining with part indexed using fourth and fifth axes. This technique has long been in practice due to its ability to save time by machining complex or multi-faceted features in a single set-up. Some other benefits to positional five axis machining are the effective use of short cutter due to greater reach capability; improved machining parameters (faster cutting, longer tool life); and increased accuracy simply by creating a series of orientation workplanes.

An example of Position Five Axis Machining. All six sides of this part are finished in a single set-up.

Challenge
Although set-up time was reduced for the structural component shown above using positional five axis machining, the entire process was still limited with the limitations imposed by the rigidity of tool assembly, maximum spindle power and part flexibility. When the part was programmed on CAM and run on the machine, max spindle power was exceeded during roughing resulting in spindle stall; and surface finish wasn't acceptable due to vibrating flexible part.

Vibration problems observed during finishing.

Spindle power limit exceeded during roughing.

Approach
We used SHOPPRO vibration diagnosis system to correct spindle speed, axial and radial depths of cut for finishing and adjust CAM program; then used MACHpro Virtual Machining systems as a platform to adjust feed rate for optimum spindle power consumption during roughing and for consistent tool loading for the rest.

Results

Excessive spindle loading during roughing eliminated
Chatter during finishing eliminated
Productivity improved by 25%
Finishing tolerance met
Tool life improved

President Obama Launches Advanced Manufacturing Partnership

noreply@blogger.com (Terranic Systems Inc.) — Fri, 24 Jun 2011 22:12:00 +0000

Today, at Carnegie Mellon University, President Obama launched the Advanced Manufacturing Partnership (AMP), a national effort bringing together industry, universities, and the federal government to invest in the emerging technologies that will create high quality manufacturing jobs and enhance our global competitiveness. Investing in technologies, such as information technology, biotechnology, and nanotechnology, will support the creation of good jobs by helping U.S. manufacturers reduce costs, improve quality, and accelerate product development.

The President’s plan, which leverages existing programs and proposals, will invest more than $500 million to jumpstart this effort. The President believes that even as we live within our means, we must invest to win the future. Investments will be made in the following key areas: building domestic manufacturing capabilities in critical national security industries; reducing the time needed to make advanced materials used in manufacturing products; establishing U.S. leadership in next-generation robotics; increasing the energy efficiency of manufacturing processes; and developing new technologies that will dramatically reduce the time required to design, build, and test manufactured goods. Leading universities and companies will compliment these federal efforts helping to invent, deploy and scale these cutting-edge technologies.

“Today, I’m calling for all of us to come together- private sector industry, universities, and the government- to spark a renaissance in American manufacturing and help our manufacturers develop the cutting-edge tools they need to compete with anyone in the world,” said President Obama. “With these key investments, we can ensure that the United States remains a nation that ‘invents it here and manufactures it here’ and creates high-quality, good paying jobs for American workers.”

An SME saves 32% on a mass production part with MACHpro NC Program Optimization

noreply@blogger.com (Terranic Systems Inc.) — Fri, 13 May 2011 04:03:00 +0000

Our objective in this project was to develop a best practice method for an SME to improve their production processes and make them cost-efficient. We used MACHpro software as a platform to evaluate an existing G-Code. Our first analysis of the tool path showed that the tool - part engagement was constantly varying along the path, which meant that tool was used at its full capacity only at small sections of the program, which indicated an opportunity for process improvement. In addition, we realized that single feed value was used for the entire tool path (which is a typical CAM procedure) even though the tool wasn't even removing material.

At the first stage of feed rate optimization, we configured MACHpro to maintain uniform chip load on the tool and calculate the most productive feed rates along the tool path. Then, we ran MACHpro to optimize feeds by respecting chip load and machine tool spindle limits, which generated a new program by inserting new feed commands. In MACHpro, we compared machining times for both programs and recorded time savings. Finally, we uploaded the new optimized G-Code onto the machine and tested our new program with actual cutting.

We ran old and new G-Codes on the machine, and achieved 32% reduction in cycle time with the new program. See videos below to see the feed command differences between original and optimized G-Code. Original code drove the machine at a constant feed of 25 inch/min because feed was planned based on the worst engagement condition, which was a full engagement. On the other hand, quick feed changes between 25 inch/min to 98 inch/min can be easily observed in the optimized G-Code. While optimizing, MACHpro ensured that maximum chip load and spindle power limits are not exceeded.

A new era in jet engine design?

noreply@blogger.com (Terranic Systems Inc.) — Mon, 18 Apr 2011 17:22:00 +0000

Passenger planes will have propeller type engines starting from 2025. This new engine design called Propfan is essentially similar to a jet engine with the fan placed outside the engine cover (housing) on the same axis as the compressor blades. Aircraft with propfan type engines are estimated to reduce carbon emission by 70% and fuel consumption by 30%.

The first plane designed by Wrigth Brothers called Flyer used a propeller type engine, which had been used for many years until they were replaced by jet engines. Jet engines not only increased the aircraft speed, which was limited to 700 km/h with propeller types, they also provided flight comfort because they were quite and less vibratory. Jet engines have been dominated the market since 1950's and their designs have been improved greatly for the past 20 years with the invention of new material alloys, which can stand higher temperatures. Despite jet engine's success, a search for a new engine with better fuel economy has always continued.

With green energy becoming an important topic in the recent years, Propfan technology initially developed by NASA in 1980s has received a lot of attention and development funds. Propfan is a combination of propeller and jet engine technologies. Propfan is built almost identical to a jet engine, and it basically works with the same principle: extraction of energy from a flow of hot combustion gas. Generated energy is; however, used to power an exposed fan, similar to turboprop engines. In other words, thrust is generated by propellers placed outside the engine not by the exhaust jet. Propfan engines have

the fuel efficiency advantages of propeller type engines, and

the performance capability of commercial jet engines.

Recent tests of Propfans showed 30% less fuel consumption compared to jet engines. Tom Williams, executive vice president for programmes and former head of Airbus in the UK, believes that Propfans will be in service by 2025. They will first be used on short to mid range aircrafts. Williams said "Airlines are looking for technologies that will greatly reduce their fuel consumption, and Propfan technology is very likely to succeed."

Titanium Machining: The Effect of the Cutting Parameters

noreply@blogger.com (Terranic Systems Inc.) — Thu, 10 Mar 2011 16:26:00 +0000

Titanium having a density only about 60% of steel has a far greater strength than many steel alloys. However, titanium has many difficulties in machining. It has a low conductivity and therefore heat due to cutting does not dissipate quickly. This results in concentration of heat on the cutting edge and hence greatly limits the machinability of this material.

In titanium machining tool life is greatly affected by the following cutting parameters listed in the order of decreasing effect, i.e., the least influential one for tool life is the one at the bottom of the list:

surface cutting speed
radial depth of cut
feed per tooth (chip thickness)
axial depth of cut

For roughing, the cutting speed is normally limited to 60 m/min where as finishing speeds can reach up to 250 m/min due to small radial depth and tools with rather smaller diameters.

Although high radial depth of cut increases material removal rate, heat generated due to cutting remains in the cutting zone because the time each flute spends in the air during one revolution decreases so does the cooling effect. Approximately 35% percent of the tool diameter is generally recommended as radial depth of cut for optimum tool life.

Chip thickness is greatly affected by insert shape. For heavier cuts, round inserts or inserts with low approach angle (eg., 45 or 60 degrees) are recommended due to their resistant to higher loads and chip thinning effect.

Axial depth of cut has almost no effect on too life; however, low speed, heavy machining with large diameter tools puts a demand on the torque delivery of the spindle so one has to be careful with cutting parameters in order to not stall the spindle.

Chatter: Root Cause and Tap Testing

noreply@blogger.com (Terranic Systems Inc.) — Tue, 08 Mar 2011 01:11:00 +0000

Chatter vibration is one of the biggest headache of production engineers, machinists, and NC programmers. Chatter degrades part quality, reduces productivity and shortens tool life. Without getting to the bottom of the problem, production engineers can only rely on trial and error to eliminate this problem. But what is it that causes chatter?

Like in any other form of vibration, the root cause of chatter vibrations is the flexibility of structures involved in cutting process. The most obvious flexible component is the cutting tool due to its relatively slenderness compared to the rest of the components like spindle, workpiece, or machine table; however, tool cannot be isolated from the rest of the structure. Cutting tool is held by a tool holder attached to the spindle shaft, which is supported by flexible bearings so it is this entire structural chain that is responsible from chatter vibrations. Each flexible connection can be represented with a bunch of springs and damping elements, and their strength affects the maximum depth of cut a machine can handle without chattering. Although it is mathematically possible to model spindle structure shown below, it is practically almost impossible to get accurate results due to poor analytical modeling of actual spring constants and damping values due to complex contact mechanics. Hence, production engineers resort to experimental methods when characterizing vibration behavior of a machine tool spindle.

Exaggerated Dynamic Deformation of a Spindle Shaft; and Most Flexible Joints of Machine Tools

"Tap Testing" is one of the most popular experimental identification methods. In a previous blog, we briefly talked about "Tap Testing" and how it fits into productivity optimization. Tap testing is simply ringing the tool installed on the machine using an instrumented hammer, and recording vibrations of the tool. Measured vibrations are then analyzed using complex algorithms, which is a subject of modal analysis, and flexible elements (springs and dampers elements) are calculated. Analysis and interpretation of these is a topic for another discussion; however, it is important to mention that these flexible elements are identified collectively. That is, they all interact with each other and affect each other. Since flexible elements are responsible from chatter, it means that we cannot blame the chatter purely on the cutting tool because tool holder, spindle shaft and bearings also play a role in flexibility of the tool as they all act with in one system. Practically speaking, the following statements can be made:

same tool with different overhangs have different chatter performance due to varying vibration behavior (which is obvious);
same tool set up (one tool, one overhang) on different machines have different chatter performance;
same tool set up on same model machines may have different chatter performance due to differences in spindle installation (this is one of the most frustrating cases when the same NC program does not work on another same model machine);
tool holder-spindle interface (HSK, CAT,..) affects chatter performance;
imperfections such as rust or grease on tool holder-spindle interface degrades structural strength and hence increases the chance of chatter vibrations.

We will cover more about machine tool dynamics in future blogs, touch on each of these bullets listed above, and recommend ways of battling chatter more effectively and intelligently.

Tap Testing Set-Up

MACHpro: Analyze, Verify and Optimize NC Programs

noreply@blogger.com (Terranic Systems Inc.) — Mon, 07 Mar 2011 03:45:00 +0000

Boeing is Awarded a $35 Billion Contract

noreply@blogger.com (Terranic Systems Inc.) — Fri, 25 Feb 2011 22:42:00 +0000

After a decade of delays, Pentagon awarded one of the biggest defense contracts ever to build airborne refueling tankers (flying gas stations) - to Boeing Company. These new airplanes will replace their peers from 1950s. Boeing will base the tanker on its 767 aircraft. The contract will mean 50,000 jobs.

Boeing Defeats EADS for $35 Billion Air Force Tanker Program - Businessweek

Machine Tool Sales (finally) Back to Normal

noreply@blogger.com (Terranic Systems Inc.) — Thu, 17 Feb 2011 01:11:00 +0000

Statistics from 2010 looks promising. Manufacturing industry is finally back on track and companies have started to make investment.
Machine Tool Sales Return to “Normal” – Up 75% in December

Volume Based Feed Rate Optimization: Can We Rely On It?

noreply@blogger.com (Terranic Systems Inc.) — Sun, 13 Feb 2011 06:30:00 +0000

Feed rate optimization of NC programs has started to become a hot topic for the past 5 years. Most CAM companies have developed some type of an optimization tool to adjust feed rate along the tool path. The idea behind feed rate manipulation is to dynamically change feed rate along tool paths where geometry varies. This way, a long G01 command with one feed value can be split into a number of shorter G01 commands with different feed rate. The fundamental assumption that such systems are based on, called Volume Based Optimization, is that

Process outputs such as spindle power/torque, cutting forces, tool deflection, etc... are directly proportional to the material removal rate (or the volume of material removed)...

Since CAM based systems only have the geometric information obtained from tool path simulation and workpiece geometry update, this assumption seemed valid at the time. However, researchers specialized in metal cutting prove this assumption wrong! It is very likely that two different cutting configurations with identical material removal rate may result 50%-100% difference in peak cutting forces, spindle power/torque, etc...

In order to demonstrate this, we took two different cutting conditions for a tool with 20 mm diameter and 4 flutes:

Case1. Q = 1.2 lt/min; fz = 0.2 mm/tooth; n = 15,000 rpm; ap = 10 mm, ae = 10 mm

Case 2. Q = 1.2 lt/min; fz = 0.4 mm/tooth; n = 15,000 rpm; ap = 11 mm, ae = 4 mm

Note that both Cases have identical material removal rate of 1.2 lt/min. Both processes were simulated using an advanced process analysis tool, CUTPRO, and spindle power was calculated for these high speed machining cases. As expected, results obtained from the analysis were contradicting with Volume Based Optimization assumption. Despite identical volume of material removed, maximum spindle power varied more than 30% for these two cases, i.e., Volume Based Optimization had already introduced 30% error in calculating optimized feed rates. Such high percentage of error in feed rate can cause catastrophic failure during high speed machining.

Simulated Spindle Power with conditions given for Case 1.

Simulated Spindle Power with conditions given for Case 2.

This blog shows importance of Physics Based Optimization when feed rate optimization of an NC program is requested. MACHpro Virtual Machining; therefore, is an optimization tool of choice when it comes to optimizing feed rates based on in-depth analysis of cutting mechanics, which uses tool and cutting edge geometries, workpiece material properties, machine tool kinematics and dynamics to calculate the most reliable, and accurate process outputs and hence feed rates.

MACHpro: How to Reduce Cycle Times

noreply@blogger.com (Terranic Systems Inc.) — Tue, 25 Jan 2011 01:18:00 +0000

It takes only three simple steps to set up MACHpro to analyze and optimize tool paths.

User inputs stock geometry as a CAD model; tool path file; and selects material of workpiece file from MACHpro's extensive material database. User also inputs various physical limits for MACHpro to check against during feed rate optimization. Some of these limits are already known by most process planners such as maximum chip load (provided by the tool supplier), and spindle torque & power limits (provided by machine tool manufacturer)

Tool path is executed by MACHpro to obtain the final part. Although this looks identical to CAM simulation of a tool path, MACHpro actually collects cutter workpiece contact information along tool path as the part is updated.

Using cutter workpiece contact information, MACHpro virtually analyses the entire machining process and detects NC blocks that violate user-defined limits of the process. Machining failures like tool over load, spindle over load, and chatter vibrations are all caught and necessary feed rate adjustments are automatically made. Moreover, MACHpro increases conservative feed rates and speeds up the process when for example the tool is leaving a cut or traveling in the air.

This new optimized NC program guarantees minimum cycle time while ensuring that the cutting process does not exceed any physical limits and fully utilizes the capacity of the existing equipment, tooling and processes.

MACHpro: Basics of Part Program Optimization

noreply@blogger.com (Terranic Systems Inc.) — Wed, 19 Jan 2011 00:03:00 +0000

Combining your expertise in machining with MACHpro's unique Virtual Machining technology, parts can be optimized prior to actual machining and productivity can be increased. MACHpro takes three inputs namely CAD model of the stock; original part program (tool path); and cutting tool geometries, and analyzes quality of the actual machining process. MACHpro automatically corrects feed rates of NC blocks when machining problems such as chatter vibrations and spindle overloading are detected. Corrected feed rates are inserted into the original part program and a new optimized part program is generated automatically.

MACHpro Virtual Machining is released!

noreply@blogger.com (Terranic Systems Inc.) — Wed, 12 Jan 2011 19:32:00 +0000

The most comprehensive machining process analysis and optimization software, MACHpro Virtual Machining, is released.

MACHpro is an integrated, science-based engineering software that notably improves competitiveness of manufacturing companies by significantly reducing overall cost per component through high performance machining.

Modeling and Simulation among U.S. Manufacturers: The Case for Digital Manufacturing

noreply@blogger.com (Terranic Systems Inc.) — Sun, 10 Oct 2010 22:32:00 +0000

In partnership with Intersect360 Research, the National Center for Manufacturing Sciences (NCMS) conducted a broad-based survey of U.S. manufacturers regarding the current state of digital manufacturing technologies and the drivers and barriers to expanding adoption. This study reveals the desire and potential benefits of digital manufacturing for a broad range of companies, particularly the assistance needed by small and medium-size manufacturers (SMMs) and the partnerships they would seek.

The web-based survey received 321 qualified respondents from the U.S. manufacturing community. 258 (80%) of respondents came from some industrial or commercial manufacturing sector, with the other 63 (20%) coming from the supporting communities in academia, government agencies, or trade organizations. (See Table 1.) All respondents were asked a foundation of questions concerning the drivers and barriers to the adoption of advanced technologies. Commercial organizations were asked additional questions about the role they play in product design and the current level of digital manufacturing technologies they have deployed, among other topic areas.

Digital manufacturing is the use of advanced computing technologies to employ modeling and simulation techniques for engineering, testing, or design purposes. By creating a digital model of a product, a manufacturer can perform a wide range of tests, such as manufacturability analysis or performance testing, before physically building a new design. Some of the potential benefits are improved product quality, shorter time to market, and reduced manufacturing costs.

Table 1: Survey Participants by Industry / Sector
Source: Intersect360 Research, NCMS, 2010

Industry/Sector Count

Aerospace 47

Automotive 31

Consumer Products 5

Defense / Homeland Security Contractor 49

Health Care / Pharmaceuticals 2

IT and electronics 14

Other (industry) 110

Total industry 258

Academic 12

Government Agency 30

Other (non-industry) 11

Trade or industry association 10

Total non-industry 63

TOTAL 321

The largest automotive, aerospace, and heavy equipment manufacturers in the U.S. have used high performance computing (HPC) technologies1 for digital manufacturing for decades. In fact, large-product manufacturing is the largest consuming commercial vertical market for HPC.2 Application areas at these companies run through the full cycle of computer-aided engineering (CAE), from conceiving new products to failure testing and maintenance of older ones.

Intersect360 Research estimates about half of CAE usage at automotive and aerospace companies to fall into various categories of solids testing and engineering, including concepts such as structural analysis and crash testing. About half of the rest goes to computational fluid dynamics (CFD), including aerodynamics testing in virtual wind tunnels. The remaining workflow is mostly spent on environmental analysis, such as noise, vibration, and harshness (NVH) testing, but also on process engineering, statistics analysis, and other tasks.

Despite the wide range of available applications and the well-established precedent of large companies successfully employing scalable HPC for engineering, there is a significant gap between the digital manufacturing capabilities of large manufacturers at the deployment (or lack of deployment) at SMMs.

An SME Finds the "Sweet Spot" and Achieves an Overnight Success

noreply@blogger.com (Terranic Systems Inc.) — Wed, 06 Oct 2010 01:34:00 +0000

A progressive BC manufacturing company, Redline Pro Manufacturing, has always invested into new technologies, and they have benefited greatly over the years. They transformed 450 sq. ft. garage shop with a single low end machine tool into a successful, fully automated, state-of-the-art job shop that is running around the clock and making parts for the high tech sector.

When I first met the owners of Redline Pro, I was impressed with their enthusiasm over technologies. Unlike other SMEs of their size, they were very open to learning new ways of manufacturing and getting ahead in the game. After being introduced to high speed machining techniques, they had become eager to give this a try at their facility. I was then invited to their facility to demonstrate how they could improve the productivity by "tap testing". Tap testing is an experimental method that is used to determine dynamic behavior of a machine tool, cutting tool, and tool holder assembly. This dynamic foot print is then used to determine the best possible cutting conditions or sweet spots. Although the mathematics and physics behind this process is extremely complex, MAL Inc's ShopPro software makes machinist's life very easy. An accelerometer similar to the one in iPhone is placed at the tip of the stationary tool and a light hammer blow is given to the tool. ShopPro measures the vibration at the tool tip and determines the most productive spindle speeds and depths of cut. And this was exactly what I did at Redline Pro Manufacturing and increased the productivity of a part in a way the company had never thought possible.

Read the rest of the story from the owners of Redline Pro.

Impressive Cycle Time Optimization in Stamping Die Machining

noreply@blogger.com (Terranic Systems Inc.) — Sat, 08 May 2010 23:26:00 +0000

Stamping dies are one of the most time consuming, hard to machine components of the automotive industry. A typical machining strategy for contour surface is to use ball type cutters removing material at varying depths of cut. Long overhangs from the spindle nose puts excessive loading on the tool, and spindle. In addition, constantly varying part geometry and depths of cut make it extremely difficult to maintain a proper chip load on the cutting edges. As a result, process planners typically choose conservative cutting conditions because an error in part program is not affordable when it comes to machining small quantities.

The case study below sets a good example how a legacy part program for a stamping die can be effectively optimized. Using the same equipment, tooling, and part programs, MACHpro virtually analyzed the machining process, successfully optimized feed rates and generated a new NC program that the machine was running in the video below. The result was an absolute success with an average of 25% reduction in the overall cycle time while the chip load maintained, insert breakage was avoided, and spindle was used at its maximum torque.

Machining of a Stamping Die
Insert Breakage: Eliminated
Spindle Overload: Eliminated
Machining Time: Reduced by 25%
Cost Savings: 40%
Additional Cost to the Manufacturer: Zero!

Constant feed rates in the original program inevitably resulted in chip thinning and failure of inserts, where "optimized" program by MACHpro corrected chip control and resulted in smoother high performance machining.

A striking example of chatter vibration suppression

noreply@blogger.com (Terranic Systems Inc.) — Sun, 14 Feb 2010 03:19:00 +0000

We wanted to give an example of how to increase productivity by chatter suppression. Below, you will see two videos of machining an aluminum workpiece with two different cutting conditions. The first cutting condition is selected by a process planner based on recommendations of a tool vendor:

Original cutting conditions used by the client:
15,400 rev/min, ap = 2.5 mm [0.098"] - Unacceptable chatter vibrations!

Having measured the tool dynamics, we determined productivity charts for this specific machine and recommended new cutting conditions which were a lot more aggressive than the first one. Take a look at how we successfully killed the chatter and yet improved the productivity:

New cutting conditions recommended by us:
17,000 rev/min, ap = 4.5 mm [0.177"] - No chatter yet 200% productivity gain!

How to construct productivity charts

noreply@blogger.com (Terranic Systems Inc.) — Wed, 26 Aug 2009 04:38:00 +0000

Productivity of a milling operation is directly proportional to the axial depth of cut, radial width of cut, spindle speed and chip load. Traditionally, the industry uses machinability data handbooks as a reference to select cutting conditions leading to a safe but conservative operating point. The most optimum cutting condition; however, can only be obtained by determining the limiting cutting conditions based on workpiece material properties, machine rigidity, cutting tool properties, rigidity of tool/work holding system and spindle capacity. One extremely powerful method to tune cutting conditions for optimum production is dynamic analysis.

Like any other structure, a machine tool combined with a tool holder and a cutting tool is also a dynamic structure. Each component in this chain introduces its own dynamics, which are called modes or weak-spots. When the machine tool is operational, depending on the operating point, the effect of each mode in the form of structural vibrations is seen anywhere along the chain. The most critical point in this chain is; however, the tool tip due to its direct impact on the part being formed. A measurement method to capture machine tool dynamics is called "tap testing" In tap testing, an accelerometer is attached at the tool tip to measure vibrations when the tool is excited with an instrumented hammer. MALTF developed by MAL Inc is used to collect, filter and analyze this data. Later, measured dynamics is used in process simulation software, CUTPRO, and stability lobes are generated.

Stability lobes are very powerful as they show the exact location of "sweet spots" The horizontal axis of the stability diagram is the axial depth of cut (ap) whereas the vertical one is the spindle speed. Any cutting condition selected below the curve will result in a stable, chatter-free cutting.

Industry/Sector	Count
Aerospace	47
Automotive	31
Consumer Products	5
Defense / Homeland Security Contractor	49
Health Care / Pharmaceuticals	2
IT and electronics	14
Other (industry)	110
Total industry	258
Academic	12
Government Agency	30
Other (non-industry)	11
Trade or industry association	10
Total non-industry	63
TOTAL	321