http://blog.lenoxtools.com/industrial-metal-cutting/feed/

blade failure

Choosing the Right Band Saw Blade for Your Forge

June 25, 2016 / , , , , , ,


In band sawing, forges and other industrial metal-cutting companies typically rely on two types of blades—bi-metal and carbide-tipped blades. Both blade technologies offer more performance and life expectancy than carbon steel blades, and choosing between the two types used to be fairly straightforward. However, advancements in both technologies have made it a little more difficult for companies to make the best blade choice for their operations.

While sawing is just a small part of the forging process, achieving operational excellence requires managers to optimize all aspects of the forging operation. To help forges make the best decision about the “right” blade type for their band-sawing operations, below is a brief overview on both blade types from the white paper, Selecting the Right Cutting Tools for the Job.

Bi-Metal Blades
Bi-metal blades are a common choice for most metal-cutting applications, especially since they are more affordable than carbide-tipped blades. In bi-metal blade construction, high-speed steel edge material is welded to fatigue resistant spring steel backing, providing a good combination of cutting performance and fatigue life.

Generally speaking, bi-metal blades are sub-divided into the following two categories:

  1. General-purpose blades are often used for easier-to-cut metals such as aluminum and non-ferrous metals, carbon steels, structural steels, and some alloy steels. These blades are also good for switching between different metal types and sizes, as well as from solids to structural pieces. However, some industry experts warn to be judicious when switching between different metal types, sizes and shapes, as subjecting blades to different types of cutting can shorten blade life.
  2. Production-sawing blades tend to be more versatile and are able to cut everything from the easiest-to-cut materials to difficult-to-cut nickel-based alloys. These blades are also ideal for cutting structural pieces and bundles, and they typically offer a long blade life and fast, straight cutting.

Carbide-Tipped Blades
Like bi-metal blades, carbide-tipped blades are made of at least two different types of material. In most cases, carbide tips are welded to a high-strength alloy back, providing a longer lasting, smoother cutting blade.

Although carbide-tipped blades are typically more expensive than bi-metal blades, shops may elect to trade up to a carbide-tipped blade for three key reasons:

  1. longer life
  2. faster cutting
  3. better finish

The various choices of carbide-tipped blades will cover the machinability spectrum, but they are most often used for hard-to-cut materials like super alloys. High-performance carbide-tipped blades work especially well with hard tool steel that needs to be cut fast. Some high-performance carbide-tipped blades—especially coated versions—can offer extreme cutting rates, while others can perform exceptionally well when cutting super alloys.

Weighing the Options
As explained in the white paper, Top 5 Operating Challenges for Forges that Cut and Process Metal, having the right blade for the job optimizes cut times, cut quality, and blade life, especially when cutting tougher metals like stainless steel and super alloys. This is particularly important in forged materials, which require aggressive blades with varied tooth geometries that can get underneath any scale buildup.

Of course, there will always be instances when the “right” blade choice won’t be clear cut and will require managers to strategically choose between a “good,” “better” and “best” option. For example, bi-metal band saw blades have been traditionally used for easier-to-cut metals such as aluminum and non-ferrous metals, carbon and structural steels, and some alloy steels. However, as featured here in Modern Metals, LENOX offers a carbide-tipped band saw blade that has been designed specifically to cut aluminum and non-ferrous alloys. The new blade has a range of features that are optimized  for aluminum cutting applications, including a specialized grade of carbide on the tip, a multi-chip tooth pattern, and a high rake angle.

Another example is noted in an article from Canadian Industrial Machinery. According to the article, bi-metal blades can be used to cut super alloys; however, as the article explains, cutting speeds will need to be slower and blades will wear out faster than when using carbide blades. “An experienced operator can adjust parameters to cut the occasional super alloy with a bimetal blade, but carbide is the choice to cost-effectively cut large quantities of hard materials,” the article states. “Blade choice comes down to a cost-per-cut situation and what fits with a shop’s operation.”

Making the Right Choice
Indeed, blade selection needs to take into account the total operational costs of running the blade, including maintenance costs and equipment requirements. Case in point: While carbide-tipped blades are more advanced in the right application, they do not perform well with a lot of vibration. Therefore, they can only be used with certain saws. Metal-cutting operations using carbide-tipped blades need to make sure they are using a saw that can run the blade speeds that are required.

In the end, the “right” blade choice requires forges to weigh the following:

By understanding some of the basic features of each blade type and then strategically assessing operational needs and goals, managers can make informed purchasing decisions that will factor into the bottom line and, ultimately, contribute to the shop’s overall success.

blade failure

Tips for Improving Circular Saw Blade Life in Ball and Roller Bearing Production

May 30, 2016 / , , , , , , , , , ,


For any metal-cutting operation, bottlenecks are the enemy. Whether caused by machine error, tooling failure, user error, or some other maintenance issue, the end result is typically the same—increased downtime, rework, and scrap, all of which eat into the bottom line. And for a high-production operation like ball and roller bearing manufacturing, a hiccup in early sawing operations can quickly wreak havoc on the entire production process and schedule.

Although circular sawing may seem like a simple operation, there are number of variables that play a role in achieving consistent, quality cuts while also getting the most out of each saw blade. As an archived article from Fabricating & Metalworking explains, “Saws are very much like the people who use them: they don’t react well to heat, shock, abrasion, stress, and tension.” Far too often, managers and operators ignore these critical factors and, as a result, experience premature blade failure and end up going through far more blades than necessary.

Proper cutting speeds, feed rates, blade tension, and lubrication all tie into blade life—a factor any blade buyer knows is critical when it comes to cost.

“Precision circular saw blades can be upwards of  $200 a piece, so you don’t want to just go through those,” Mike Baron, vice president of Jett Cutting, says in a case study published by the LENOX Institute of Technology (LIT). “If I am getting 100 pieces an hour at this setting, but push it up to get 150, I may be going through twice as many blades. It just isn’t cost effective.”

Glen Sliwa, maintenance manager at metal service center A.M. Castle & Co, also focuses on blade life to better manage costs. In addition to following a strict preventative maintenance program to save on tooling and equipment costs, Sliwa says it is just as critical to ensure operators know how to optimize blade life. This includes training operators to follow manufacturer suggested cutting parameters, as well as closely tracking tolerance requirements so blades can be reused whenever possible.

“We’re looking at how many pieces that we can get off that blade and then stand perpendicular to the part,” Sliwa explains. “If you have to stay within ten-thousandths or five-thousandths on the cut, and that blade is no good, I can take it off that machine and put it on another one and I can cut an eighth of an inch, 125 thousandths. So I’m still getting more blade life out of it, but it’s not interfering with that customer’s specifications.”

To help ball and roller bearing manufacturers extend the life of their circular saw blades, the below chart offers a few troubleshooting tips from LIT’s reference guide, “Tips and Tricks to Optimize Your Precision Circular Sawing Operation.” By understanding some common blade issues and their root causes, operators can reduce premature blade failure and, in turn, improve your  operation’s overall productivity and save on tooling costs.
chart 3

For more downloadable information on optimizing your company’s precision circular sawing operation, you can visit LIT’s resource page here.

blade failure

Small Optimization Opportunities for Your Machine Shop

March 20, 2016 / , , , , , , , , ,


Although the metalworking industry was hoping 2016 would be a year of growth, recent reports show continued declines in both new orders and production rates in February. While no one is worried that business is going to completely plummet, the sobering reality is that shops need to continue to focus on cost reduction and optimization to survive in today’s unpredictable and competitive market.

The challenge for many shops is figuring out where to optimize. After a few rough years, many shops have already implemented large-scale improvements to increase efficiency and save costs.  According to the results of Modern Machine Shop’s annual Top Shop Survey, 62 percent of leading machine shops (or “top shops”) have developed a formal continuous improvement program, and most use manufacturing tools like 5S workplace organization, cellular manufacturing, and value stream mapping.

What else, then, can possibly be improved? For some shops, the answer may be to “think small.” Take band sawing as an example. When thinking about optimization, the instinct for most operation managers is to focus on the efficiency of the saw, the workflow process, and maybe even the operator. But what about the tools? Could they be optimized?

If we are talking about band saw blades, the answer is yes. As explained in the LENOX Guide to Band Sawing, completing a proper break-in procedure on a new band saw blade will significantly increase its life (see photo). This not only allows the shop to cut more material, it also reduces unnecessary downtime to replace blades and lowers the cost of replacement blades.

When it comes to consumable tools like blades, many machine shops fail to understand the critical role they can play in the overall success of their sawing equipment and, ultimately, their entire operation.  In fact, according to a benchmark study of machine shops and other industrial metal-cutting companies, less than half (45%) of the organizations surveyed reported they “always” break in blades, 30 percent said they do it “most of the time,” and 15 percent said they do it “occasionally.” This means that the majority of industrial metal-cutting shops are missing out on a simple and effective opportunity for optimization.

This can be true of other “small” aspects of your cutting operations. As covered here in an earlier blog post, running blades at the right speed settings and proper lubrication can also directly affect your shop’s productivity, costs, and quality. Other metalworking operations, such as welding and punching, have similar best practices that offer opportunities for optimization, allowing you to get the most out of your manufacturing tools.

Like any change, optimization starts small. What areas of your shop’s operations are you overlooking?

For more bandsawing tips, including how to properly break-in blades, click here to download LENOX’s Guide to Bandsawing.

blade failure

Choosing the Right Blade for Your Fabrication Shop’s Band Saw Operations

March 10, 2016 / , , , , , , ,


In band-sawing, fabricators and other industrial metal-cutting companies typically rely on two types of blades—bi-metal and carbide-tipped blades. Both blade technologies offer more performance and life expectancy than carbon steel blades, and choosing between the two types used to be fairly straightforward. However, advancements in both technologies have made it a little more difficult for companies to make the best blade choice for their operations.

For example, bi-metal band saw blades have been traditionally used for easier-to-cut metals such as aluminum and non-ferrous metals, carbon and structural steels, and some alloy steels. However, as featured here in Modern Metals, a new carbide-tipped band saw blade has been introduced by LENOX that has been designed specifically to cut aluminum and non-ferrous alloys. The new blade has a range of features that optimize it for aluminum cutting applications, including a specialized grade of carbide on the tip, a multi-chip tooth pattern, and a high rake angle.

To help metal fabricators make the best decision about the “right” blade type for their band-sawing operations, below is a brief overview on both blade types from the white paper, Selecting the Right Cutting Tools for the Job.

Bi-Metal Blades
Bi-metal blades are a common choice for most metal-cutting applications, especially since they are more affordable than carbide-tipped blades.

Generally speaking, bi-metal blades are sub-divided as either general-purpose blades or production-sawing blades:

Carbide-Tipped Blades
Although carbide-tipped blades are more expensive, machine shops may elect to trade up to a carbide-tipped blade for three key reasons:

The various choices of carbide-tipped blades will cover the machinability spectrum, but they are most often used for hard-to-cut materials like super alloys. High-performance carbide-tipped blades work especially well with hard tool steel that needs to be cut fast. Some high-performance carbide-tipped blades—especially coated versions—can offer extreme cutting rates, while others can perform exceptionally well when cutting super alloys.

Making the Right Choice
Of course, there are instances when the “right” blade choice won’t be clear cut and will require managers to strategically choose between a “good,” “better” and “best” option. For example, as this article from Canadian Industrial Machinery (CIM) explains, bi-metal blades can be used to cut superalloys. However, cutting speeds will need to be slower and blades will wear out faster than when using carbide blades. “An experienced operator can adjust parameters to cut the occasional superalloy with a bimetal blade, but carbide is the choice to cost-effectively cut large quantities of hard materials,” the article states. “Blade choice comes down to a cost-per-cut situation and what fits with a shop’s operation.”

Blade selection also needs to take into account the total operational costs of running the blade, including maintenance costs and equipment requirements. Case in point: While carbide-tipped blades are more advanced in the right application, they do not perform well with a lot of vibration. Therefore, they can only be used with certain saws. Metal-cutting operations using carbide-tipped blades need to make sure they are using a saw that can run the blade speeds that are required. In other words, the saw must have a motor that can push the blade fast enough and one that has a more rigid construction with better vibration dampening to accommodate these types of blades.

In the end, the “right” blade choice requires fabricators to weigh the following:

By understanding some of the basic features of each blade type and then strategically assessing operational needs and goals, managers can make informed purchasing decisions that will help their metal-cutting operations reach their full potential and, ultimately, achieve market success.

blade failure

Tips for Preventing Premature Band Saw Blade Failure in Your Forging Operation

January 25, 2016 / , , , , , , , , , , ,


For any metal-cutting operation, blade life is critical. Premature blade failure not only results in increased tooling costs, it can also increase downtime, rework, and scrap—all of which eat into the bottom line.

For forges that cut and process metal, however, blade life is even more crucial. The scale that forms on forged metal pieces can quickly deteriorate blade life, which makes blade selection extremely important. In most cases, forges require aggressive bandsaw blades with varied tooth geometries that can get underneath any scale buildup (i.e., carbide-tipped blades).

While choosing the right blade is a good start, blade life also relies on a variety of other variables, including proper cutting speeds, feed rates, blade tension, lubrication, and break-in procedures. As an article form Fabricating & Metalworking explains, “Saws are very much like the people who use them: they don’t react well to heat, shock, abrasion, stress, and tension.” Far too often, managers and operators ignore these critical factors and, as a result, experience premature blade failure and end up going through far more blades than necessary.

To help forges extend the life of their band saw blades, below are a few troubleshooting tips from the reference guide, “User Error or Machine Error?”, from the LENOX Institute of Technology. By understanding some common blade issues and their root causes, operators can reduce and, hopefully, eliminate premature blade failure.

Issue #1: Heavy Even Wear On Tips and Corners Of Teeth
The wear on teeth is smooth across the tips and the corners of set teeth have become rounded.

Probable Cause:

Issue #2: Wear On Both Sides Of Teeth
The side of teeth on both sides of band have heavy wear markings.

Probable Cause:

Issue #3: Wear On One Side Of Teeth
Only one side of teeth has heavy wear markings.

Probable Cause:

Issue #4: Chipped Or Broken Teeth
A scattered type of tooth breakage on tips and corners of the teeth.

Probable Cause:

Issue #5: Body Breakage Or Cracks From Back Edge
The fracture originates from the back edge of band. The origin of the fracture is indicated by a flat area on the fracture surface.

Probable Cause:

For more information on extending blade life, download the full reference guide, “User Error or Machine Error?” here, or check out The LENOX Guide to Band Sawing.

blade failure

Predictive Technology Helps Industrial Metal-Cutting Companies Stay Ahead of the Curve

January 15, 2016 / , , , , , , , , ,


The U.S. manufacturing landscape is changing, and industrial metal-cutting companies are no exception. Technology has created an increasingly connected industry, and manufacturers are realizing that while traditional lean practices have proved successful in the past, when it comes to operational efficiency, data and other advanced “smart” technologies are the wave of the future.

One area that is quickly gaining popularity is the use of predictive technologies. As reported in a recent Manufacturing.net article, nearly three dozen manufacturing company executives and national research facility directors identified predictive data analytics as the number one advanced manufacturing technology critical to growth, as part of a study conducted by Deloitte Global and the U.S. Council on Competitiveness.

Predictive analytics utilizes a variety of statistical and analytical techniques to develop mathematical models that “predict” future events or behaviors based on past data. As the study explains, this allows companies to uncover hidden patterns, relationships, and greater insights by analyzing both structured and unstructured data.

Several industries are already benefiting from the use of predictive technologies. Healthcare, for example, is using predictive analytics to improve the effectiveness of new procedures, medical tests, and medications. Manufacturing companies are using the technology to identify quality and production issues, as well as optimize delivery and distribution. Other industries, such as aerospace, automotive, and consumer products, are also finding interesting applications.

Thyssen Krupp, for example, recently used predictive analysis to improve the reliability of more than 1.1. million elevators it maintains worldwide. With the help of Microsoft cloud technology, the company gathered data from thousands of sensors and systems in its elevators to measure motor temperature, shaft alignment, cab speed and door functioning. After being sent to the cloud, the data is then displayed on a single dashboard in real-time. The data is also used in predictive model formulas, helping technicians know when and where a failure may occur.

The trend is also finding its way into industrial metal cutting. Data from the LENOX Institute of Technology’s Benchmark Survey of Industrial Metal-Cutting Organizations suggests that investing in smarter, more predictive operations strategies can help companies gain additional productivity and efficiency on the shop floor.

Although not through the use of analytics, the benchmark survey found that industry leaders are using strategies such as planned maintenance and blade care to prevent downtime and predict blade failure. Specifically, the benchmark study found that:

While there is no question that predictive analytics is still an emerging area, it is clear that proactive strategies are key in today’s uncertain market. Whether you invest in advanced predictive analytics software or simply stick to your preventative maintenance program, finding ways to anticipate future events and reduce unplanned downtime can help your operation gain efficiency and, more importantly, stay competitive.

What predictive operational strategies are you using to make your operation more efficient?

blade failure

Making the Right Band Saw Blade Choice in Your Machine Shop

December 20, 2015 / , , , , , , , , ,


For decades, machine shops and other industrial metal-cutting companies have mostly relied on two types of band saw blades—bi-metal and carbide-tipped blades. Both blade technologies offer more performance and life expectancy than carbon steel blades, and choosing between the two types used to be fairly straightforward. However, advancements in both technologies have made it a little more difficult for companies to make the “right” blade choice.

For example, bi-metal band saw blades have been traditionally used for easier-to-cut metals such as aluminum and non-ferrous metals, carbon and structural steels, and some alloy steels. However, as featured here in Modern Metals, a new carbide-tipped band saw blade has been introduced by LENOX that has been designed specifically to cut aluminum and nonferrous alloys. The new blade has a range of features that optimize it for aluminum cutting applications, including a specialized grade of carbide on the tip, a multi-chip tooth pattern, and a high rake angle.

As this archived article from Production Machining notes, next-generation coatings and more complex tooth designs in both bi-metal and carbide blades have given metal-cutting companies more high-performance cutting options. Although this is certainly a good thing for end users, it can also make it more difficult for managers trying to decide between a “good” and “best” blade choice.

To help machines shops make the best decision about the “right” blade type for their band-sawing operations, below is a brief overview on both blade types from the white paper, Selecting the Right Cutting Tools for the Job.

Bi-Metal Blades
Bi-metal blades are a common choice for most metal-cutting applications, especially since they are more affordable than carbide-tipped blades.

Generally speaking, bi-metal blades are sub-divided as either general-purpose blades or production-sawing blades:

Carbide-Tipped Blades
Although carbide-tipped blades are more expensive, machine shops may elect to trade up to a carbide-tipped blade for three key reasons:

The various choices of carbide-tipped blades will cover the machinability spectrum, but they are most often used for hard-to-cut materials like super alloys. High-performance carbide-tipped blades work especially well with hard tool steel that needs to be cut fast.

While these blades cost more upfront, they are designed to take more bite and more chip load, which allows for faster cutting and typically save costs in the long run. Some high-performance carbide-tipped blades—especially coated versions—can offer extreme cutting rates, while others can perform exceptionally well when cutting super alloys.

Balancing Cost with Productivity
In some cases, the decision between bi-metal and carbide-tipped blades may not be crystal clear and will require some strategic choices. Ultimately, to make the best saw blade selection, operation managers need to weigh the following:

This may mean that a shop will have to spend a little more upfront to save money in the long run. Like any equipment and tooling investment, blade selection should be about more than the initial price tag. By understanding some of the basic features of each blade type and then strategically assessing operational needs and goals, managers can make informed purchasing decisions that will help their metal-cutting operations reach their full potential and, ultimately, achieve market success.

blade failure

Key Considerations When Forging and Cutting Aluminum

November 30, 2015 / , , , , , , , ,


Anyone working in the metals industry knows that use of aluminum is growing. Even with fluctuating prices, aluminum demand is still much stronger compared to other metals, including steel and copper.

Thanks to rapid growth in the transportation and construction industries, aluminum’s upward trend is expected to continue over the next several years. According to one market report, the worldwide market for aluminum alloys is expected to grow at a compound annual growth rate (CAGR) of 4.8 percent through 2020, with market revenue rising in the U.S. from $91.2 billion in 2013 to $126.5 billon in 2020. Another report states that in the global automotive industry alone, aluminum use is expected to grow at a CAGR of 7.4 percent over 2015-2020.

As key suppliers to the automotive and other aluminum-consuming industries, forges need to ensure their skills and equipment line up with market demand. Like any material, aluminum’s unique properties require manufacturers to be equipped with the right metalworking tools and techniques.

Out of all of the various groups of alloys, aluminum alloys are the most readily forged into precise, intricate shapes. As explained by the Forging Industry Association, this is because aluminum alloys are:

While these properties certainly make aluminum alloys ideal for forging, they also have different requirements compared to other forged materials. For example, as an archived article from Forging magazine explains, temperature controls and furnace construction for aluminum are different from those used with ferrous materials. Specifically, indirect-fired or electric resistance-type furnaces equipped with internal fans are often preferred for aluminum. In most cases, the article states, this usually means new furnaces for the steel forger contemplating forging aluminum.

Other forging processes such as trimming, heat treatment, and quality inspection also need to take aluminum’s distinctive attributes into consideration, as described here in the Forging article. The same holds true when sawing aluminum. Forges that cut and process metal need to make sure they understand what is needed to cost-effectively and efficiently cut aluminum.

While aluminum is a softer material, it is also abrasive, which can present some machining challenges. According to a recent article published in Canadian Industrial Machinery (CIM) magazine, aluminum’s abrasive property can wreak havoc on a saw blade, accelerating tooth wear and diminishing blade life. This not only increases blade costs and downtime due to constant blade changes, it can also affect cut quality and overall productivity. However, smart blade choices can help overcome this common cutting challenge.

To combat aluminum’s abrasive quality, most manufacturers recommend carbide-tipped band saw blades over bi-metal blades. This is because carbides are harder, tougher, and more durable, Matt Lacroix of LENOX  explains in the CIM article. “Carbide tips are slower to wear and better suited to handle the high machining speeds,” Lacroix writes. Other blade factors, such as backing steel and tooth geometry, can also help improve the efficiency of sawing aluminum, he adds.

As the use of aluminum grows, it is more critical than ever for forges to fully understand the material’s unique characteristics and machining requirements. For more information on how to cut aluminum, you can read the full CIM article, “Taking the Hard out of Cutting Soft,” here. The Aluminum Association also provides a brief overview on aluminum forging here.

blade failure

Reducing Metal Scrap and Rework in Your Machine Shop

September 20, 2015 / , , , , , , , , , , , , , , ,


In any manufacturing operation, a small amount of scrap is inevitable. However, reducing material waste should still be a top goal for machine shops that cut and process metal. Like all other forms of waste, scrap can negatively affect profitability, especially if it is generated as a result of an error.

The truth is that any amount of scrap or rework you’re experiencing in your operations provides an opportunity for improvement. Taking the time to reduce scrap often leads to better productivity and higher quality cuts. As this manufacturing.net article points out, eliminating scrap and waste also contributes to your company’s environmental efforts, which may be important to some customers.

How can you keep your scrap and rework costs low? While there are several ways to accomplish scrap reduction, below are a few simple strategies any machine shop can implement:

 

blade failure

Solving the Six Common Cutting Challenges Ball and Roller Bearing Manufacturers Face

August 30, 2015 / , , , , , , , , , , ,


Like most high-production operations, ball and roller bearing manufacturers are running on tight schedules and can’t afford unexpected downtime or tooling issues. This means that every step of the manufacturing process must be optimized, starting with the first operation—circular sawing.

While precision circular sawing may seem like a simple operation, any metal-cutting expert can confirm that proper cutting depends on several variables. As this article from Canadian Metalworking points out, the overall performance of your cutting tool depends on speed, feed, depth of cut, and the material being cut. Knowing how to balance these variables is critical to cutting success.

For example, according to the white paper, The Top Five Operating Challenges Ball and Roller Bearing Manufacturers Face in Industrial Metal-Cutting, increasing the speed of a saw to get more cuts per minute without considering the feed setting or the demands of the material will result in premature blade failure and increased tooling costs. This, in turn, can lead to unplanned downtime for blade change-out, which directly impacts productivity.

Understanding how these different variables affect the cutting process can also help operators quickly and properly resolve any cutting challenges that arise. In many cases, this knowledge can make or break a production schedule.

To help ball and roller bearing manufacturers keep their circular sawing operations running at optimal levels, the LENOX Institute of Technology offers the followings tips for solving six of the most common problems operators may face:

Problem #1: Excessive vibration or noise
Potential solutions:

Problem #2: Crooked cutting
Potential Solutions:

Problem #3: Wavy cutting
Potential Solution:

Problem #4: Chips are too hot or glowing
Potential Solutions:

Problem #5: Poor finish/Excessive stripping
Potential Solutions:

Problem #6: Heavy burr
Potential Solutions:

For more information on optimizing your precision circular sawing operation, including best practices, white papers, and case studies, check out LIT’s resource center here.

1 2 3 4