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The Different Types of Excavators

Also referred to as a backhoe or digger, an excavator is a heavy piece of heavy machinery that is generally used to dig into the ground. An excavator can also be used for building roads, structures and mining various types of minerals.

Because an excavator is such a large piece of machinery, digging jobs are more efficient and effective when the machine is being used due to the amount of materials that it is capable of picking up.

Adding to their versatility, an excavator comes in a variety of different sizes. Ranging in size from smaller machines that can fit into your backyard to gigantic pieces of equipment that are used to excavate enormous rocks and mining substances like gold, soil and diamonds, an excavator serves many purposes. Helping various construction workers make their jobs much easier, an excavator can greatly decrease a projects operational cost while also increasing worker productivity.

Hydraulics in Excavating

The majority of the excavators that are used in today’s construction world function with a hydraulic part that helps increase the amount of power that the machine uses. In a commonly used excavator, a hydraulic cylinder, a bucket, an arm and a boom will be utilized.

Working synchronized together, each part of the excavator is essential to the machine’s overall performance. Simply making a small adjustment to the excavator’s hydraulic cylinder could extremely improve or decrease the machine’s overall accuracy.

Another critical component of the excavator machine is the cab that sits on top of a platform that pivots on its tracks or wheels allowing it to move around. In order to maneuver the excavator, the machine’s operator sits in the cab and uses the control system to move around. The boom part of the machine acts similar to an arm and is able to reach out and grab whatever object or material that is needed.

In addition to being capable of extracting a large amount of dirt and other substances, the excavator is a very diverse piece of construction equipment. Machine operators are able to remove the excavator’s boom and bucket to install specialized crushing tools, drills or scissors. This allows the piece of equipment to be used to drill through harder materials like concrete.

Types of Excavators

The two main types of excavators that are typically used include a backhoe and a dragline excavator. The most common type is a crawler excavator.

A backhoe can be seen at pretty much any construction or building site and is the main piece of equipment that is used for digging. The other frequently seen type of excavator is a dragline.

This machine is usually much larger than a backhoe and is used for large mining and civil engineering jobs. Depending on the specific construction job, either a backhoe or a dragline excavator will prove to be more useful.

Why WEDM’s (wire electronic discharge machines) Are So Popular

Wire electronic discharge machine (WEDM) process is also referred to as “spark” machining, “burning”, “die sinking” and wire or spark erosion. It is used to achieve a desired shape in material, via sparks (or electrical discharges). Two electrodes are used to form a constant current. One electrode is known as the “tool”, while the other is known as the “workpiece”.

When two conductors separated by a dielectric (a film of non-conducting liquid), a quick succession of discharge (aka: electrical tension) happens. When the voltage reaches a certain point, the dielectric breakdown occurs, and the ionized channel can be created. In turn, the discharge process can begin, because the dielectric now becomes a local conductive.

During the late 1700’s, Joseph Priestly (and English scientist), made the discovery of an erosive effect caused by electrical discharge. In the early 1940’s, Soviet scientists ( B. and N. Lazarenko) came up with (and acted on) the idea that electrical discharge can be controlled, and used, for machining materials that are conductors of electrical currently. Born, from this idea, is the EDM process.

Advantages

There are many advantages to wire electronic discharge machining. The least of these, being the fact that it has the ability to create complex cuts/shape when other, more conventional cutting types of tools may fall short. Hard surfaces, such as titanium or steel and other exotic/rare materials are not a hindrance when using an EDM.

In addition, because there is no contact between the workpiece and the tool, fragile material can be successfully machined without distortion or damage.

Disadvantages

There are also a few disadvantages to using a WEDM which include the extra cost and time involved in using this type of equipment. The power consumption is high which adds to the cost of daily operation. As with any oil-based combustible machines, a fire is possible (proper precautions must be in place to ensure safety).

Top WEDM Manufacturers

Wire electronic discharge machines are the main technology used in today’s tool and mold making industry. Companies that are leading this industry include, but not limited to:

Accutex Technologies not only manufactures EDM machines, but also CNC wire cutting machines. This company serves the entire world with its machines, and boasts annual sales of 2 million dollars.

Oscar EDM Company Ltd, a company that is based in Taiwan, specializes in the manufacturing of electrical discharge machines (EDM), including the wire and drilling EDM machines.

Ocean Technologies Co., Ltd, also based in Taiwan, is another leader in exporting EDM machines across the world. In addition, this company is also known for supplying electrode tubes, ceramic guides and other equipment parts.

Belmont Equipment & Technology has all your EDM needs (including coolant drills, filter systems, wire guides and parts for charmilles edm), in addition to excellent customer service.

This company stays at the top by offering the most up-to-date technology, and offering customers a fresh and proactive approach, in meeting all their EDM needs, including increased productivity and money saving options.

Currently, there are several locations in the United States, including California, Illinois, North Carolina and Massachusetts that also serve Mexico and Canadian customers.

GF Machining Solutions is a Switzerland based company, that offers high performance EDMs (including palletizing and clamping systems) globally.

Midway Machine & Instrument Co., Inc. is a leader in manufacturing Charmilles EDM parts, and other machines parts that are vital for running oil fields, space stations and the medical industry. Based in Texas, this company serves Western Europe, North American and, of course, EDM Houston, TX customers.

Shenzhen Industry Co., Ltd, a company based in China, manufacturers grinders, CNC equipment, milling machines and electrical discharge machines (just to name a few).

Wright EDM Parts Co. Ltd. manufacturers’ parts, that are applicable for name brand wire cutting machines, such as Charmilles EDM, Maxi Art, Mitsubishi, Makino and Hitachi. In addition, they also supply drill chucks, ceramic guides and jigs, for use on EDM drilling machines.

Sheet Metal Bending Process

Sheet metal bending is the process by which force is applied to a piece of thin metal, to make it bend. This is the beginning process of making items as small as brackets or as large as chassis.

Air ducts, encasement’s for electronics and building roofs are some of the common areas that benefit from bended sheet metal.

Commonly used equipment for bending sheet metal include box brakes, pan brakes and brake presses. Although the final results may not be precise, some people want to know how to bend sheet metal by hand, and as long as the metal is thin (and small) enough – this is quite a doable task.

The process of metal bending is similar to how you would bend a piece of cardboard over a counter top edge, to achieve a straight line – the difference lies in the amount of pressure required to perform such a task.

A mallet, block of wood and a stake may be some tools that are required in bending sheet metal by hand, without the assistance of a hydraulic or computer controlled brake press (which are tools mainly used in producing a high volume of product).

Types of sheet metal bending methods

Air Bending

This method of bending sheet metal is done by a “punch” (also known as the “top” or “upper” die) being pressed into the material, and forcing it into the V-shaped bottom die. The bottom die (often referred to as “tools”) can either be square or “V” shaped.

A couple of advantages of using the air bending method are that a variety of materials (and thickness) can be bent in a variety of different angles, which allows for much flexibility with this method. In addition, there are less tool changes, which allows for higher product output.

Due to the fact that the sheet is not in constant contact with the dies, the disadvantage to air bending is that it may not be as accurate as other types of sheet metal bending methods.

This minor disadvantage does not hinder the fact that air-bending remains the preferred method of sheet metal bending.

Bottoming

With this sheet metal forming process, the sheet is forced into a “V” shape opening. With this method, the “U” shaped opening option cannot be used.

The advantage with using the bottoming sheet metal bender is that you achieve greater accuracy with little spring back. The minor disadvantage is that for each thickness, bend angle and material change, a different tool setting is needed.

Coining

Coining offers the most precision than other bending sheet metal process, but this method is very costly and rarely used.

Folding

In this process, the long sides of the sheet are clamped, and the beam rises and the sheet folds around the profile. This process is excellent for large sheets, and surface damage is minimal (if at all) with this sheet metal bender.

Wiping

Wiping works in the same manner as the folding process, although it may be faster. The risk of damaging the sheets and producing scratches on the final piece is higher. A special tool attachment is required if using the wiping method on a press brake.

Rotary bending

This method is similar to wiping, but the top die is a free rotating cylinder, and the shape is cut to match the bottom die. This method of sheet metal bending is recommended for surfaces that have been painted. The advantage to this method is that in one single hit, an angle of more than 90 degrees can be achieved.

CNC Mini Lathes

Computer numerical control (CNC) mini lathes are essentially a smaller sized version of an industrial CNC lathe. CNC mini lathes are most often used to produce very small parts more economically than on a large lathe or to machine very small parts that cannot be made using a larger CNC lathe.

Many mini lathes are designed to fit on a bench top or desktop and other models are designed to be compact and take up only a small footprint on a shop floor.

Lathes are used to make components like shafts and bushings, parts that are cylindrical in shape. In reality, almost all mechanical and engineering devices utilize parts made on a lathe. Lathes are perfect for those who dabble in robotics, race cars, planes, boats, appliances, jewelry and just about any hobby.

Home professionals and hobbyists that create small objects constitute the primary user group for CNC mini lathes. CNC mini lathes and mini machining centers are also used extensively for engineering education and machining training as well as small manufacturing runs.

These mini CNC lathes are used to turn or spin a metal cylinder at a very high speed while it cuts metal to create a new part. Some CNC mini lathes with advanced programming and machine design can even cut complex curves and shapes like their industrial counterparts. Mini lathes are also useful to cut lightweight materials including wax, and plastics.

CNC Mini lathes have a lot of potential to optimize small batch manufacturing and for prototyping and R & D but most CNC mini lathes still have some shortcomings although the technology has definitely improved. It is always best to check with a qualified machinist or engineer to discuss your specific needs and which type of mini lathe or standard lathe best meets your needs.

What to Look for When You Buy a CNC Mini Lathe

There are not too many CNC mini lathes on the market. In many cases lathes come prepared to add CNC controls and in other cases individuals will buy the peripheral equipment and turn a manual or automatic mini lathe into a CNC lathe.

If you are thinking about purchasing a CNC mini lathe you should make certain that the CNC mini lathe is capable of delivering the accuracy and precision you need for your application.

CNC mini lathes are generally not able to maintain the high levels of accuracy and precision of standard CNC lathes designed for industrial use. Another thing to consider when buying a mini lathe is the durability of the machine and the parts.

A mini lathe should also have enough mass to remain stable during use. If you need to perform multiple operations you should also investigate the work-holding options available and the ease of operation to change tooling.

SIEG

Shanghai SIEG machinery Co., Ltd was founded in 1988. They manufacture mini lathes and milling centers OEM for many different companies. They may well be the premier manufacturer of mini machine tools for DIY, hobbyists and education and training facilities.

SIEG CNC mini lathes feature high reliability, simple operation, 2 axis step motor, high torque brushless motor, metric MT3 spindle, high strength guideway. SIEG also sells a variety of optional accessories and cutting tools as well as stands and a cooling system for the lathe. The CNC mini lathe for DIY and hobbyists comes in two models.

Additional CNC lathe models are available for Education and training and light industrial applications.

Tormach

Tormach designs and manufactures a line of personal CNC machine tools specifically for light industrial and home hobby use. Their duality CNC lathe is unique in the world of CNC machines. It offers two operation modes.

Without your Personal CNC mini milling machine it functions identically to traditional manual mini lathes but when it is mounted on to the bed of the Personal CNC 1100 mini milling machine it becomes a small CNC prototyping lathe that costs only a fraction of the cost of a free standing lathe.

In the CNC mode, the duality lathe is mounted to the PCNC 1100. It uses a rigid quick change lathe tool post that is mounted to the spindle cartridge of the PCNC 1100 and CNC lathe software to provide precise motion of the lathe operations on the X and Z axes.

In the CNC mode, the mill table moves the duality mini lathe left and right while the mill spindle head moves up and down so that all conventional CNC lathe operations are available such as turning, cut off, boring, drilling, and threading. No threading gear changes, radius attachments, or taper attachments are required.

Tormach also offers slant bed compact CNC lathes designed for prototyping and specialty manufacturing of turned parts. It features a cast iron frame, 15” diameter swing over the bed, a 3 HP spindle up to 3500 RPM, a D1-4 Nose with removable 5C taper insert, 25” carriage, rigid tapping capability along with standard conversational control, configurable tooling, optional 8 station turret and full enclosure, work holding and a 12 month factory warranty.

Haas Automation Inc

Haas Automation offers an office lathe that is designed to deliver high performance and reliability to industries that cannot fit a standard CNC lathe into their facility. This compact lathe is designed for high production or rapid prototyping of small, precision parts.

This lathe fits through a standard 36” door and into most freight elevators. It also delivers a higher level of precision and accuracy than generally found in other mini lathes.

How Machining Tools Are Used in the Aerospace Industry

Most aircraft engines are primarily constructed of metal components, though there are now plastic composite materials that are being used for certain parts. For parts that require great strength, but light weight such as structural components, compressor sections and engine frames, various aluminum and titanium alloys are used.

For parts that need high heat and temperature resistance, chromium, nickel and cobalt alloys are favored. Steel is used in a variety of locations on aircraft.

In reality, almost every common metalworking and machining operation is involved in the manufacturing of an aircraft engine. The processes used include hot forging for airfoils and compressor disks, casting of all structural components and engine frames, grinding, turning, drilling, broaching, milling, shearing, sawing, threading, welding, brazing and thermal or plasma spraying.

The reason almost all machining tools are involved in aircraft manufacturing is that the materials used all have very high strength and hardness. There is also the need for complex shaping and precision tolerances that can only be achieved with computer controlled machining.

Apart from the common types of machining processes, the aerospace industry also uses some unique metalworking processes like chemical and electrochemical milling, laser drilling, electron beam welding and electro-discharge machining.

Chemical and Electrochemical Milling

These two processes are used when there is a need to remove metal from large surfaces in a way that either retains or creates a contour. Depending on the alloy, the parts are placed in acid, caustic or electrolyte bath that is high concentrated and controlled. The metal is removed by the chemical or electrochemical action.

These processes are most commonly used in the aerospace industry to work with airfoils after they have been forged to reduce wall thicknesses down to precise specifications while maintaining the contour of the airfoil.

Electro Discharge Machining and Laser Drilling

These processes are utilized to make small diameter holes or very intricate contours in hard metals. Combustor and turbine components need these types of holes to ensure proper cooling.

Metal is removed by the high frequency thermo-mechanical action of electro-spark discharges. The process is done in a dielectric mineral oil bath. The electrode works as the reverse image of the desired cut.

Electron-Beam Welding

Electron-beam welding joins parts where a deep weld penetration is required in difficult to access areas. A focused, accelerated beam of electrons in a vacuum chamber are used to generate the weld. The heat for the weld is generated by the kinetic energy of the electrons when they strike the work piece.

CNC Machining

CNC machining uses computers to control various machine tools. Some of the tools that can be controlled with computers include lathes, mills, routers and grinders. It is the computer’s software and control console that sets apart CNC machines.

Machine tools function by numerical controls. Each machine is customized to the precise measurements for the specific object being manufactured. The machine is programmed using a machining language that controls all activities including the feed rate, coordination, location and speeds. CNC machines can control the exact positioning and speed, and can be used with both metal and plastic parts.

The benefit of CNC machining in precision industries like aerospace and automotive manufacturing is that the process is much more precise than manual machining and it can be precisely repeated over and over again, making it especially cost effective for high volume manufacturing jobs. The other benefit of CNC machining is that it allows the production of very complex shapes that would be impossible with manual machining.

Tolerances

CNC machining is critical to the aerospace industry because of the extremely tight tolerances required. Manual machining cannot ensure that these tolerances can even be met, let alone met consistently.

The ability to program precise measurements and reproduce them in volume is essential to keeping down costs and meeting safety requirements, as well as manufacturing requirements for these extremely small allowable tolerances.

This is one of the key benefits of computer controlled machining. The direction for CNC machining is to partner the machines with extremely sophisticated measurement systems to ensure tolerances are met.

Productivity

CNC machining has evolved over time and reached new levels of versatility with respect to the tools that they utilize. Machines can be assigned different tasks and use different tools so that they provide the aerospace industry with high levels of productivity. Both tools and networks can be switched without affecting the speed of production.

It is also possible for one machine to do more than one task simultaneously. This outperforms the capacity of any human. Another productivity benefit with CNC machining is that when one machine tool breaks, it can easily be taken off the grid, preventing it from affecting the whole production line. The tool can be replaced or repaired right on the production floor.

SUMMARY

The aerospace industry faces many challenges in the production of their products, be it an airplane, or military equipment. With complex three-dimensional shapes, high volumes and tight tolerances, the ability to mass produce parts cannot be handled manually. The materials used in aerospace manufacturing are especially durable and strong.

For all of these reasons, CNC machining plays an important role because computer controlled machines and robots provide a greater capacity to cut complex shapes and form strong, hard materials with consistency to meet the high tolerance demands of the industry.

Safety in the Warehouse

1. Clutter and disorganization can lead to injury. It is important that all sharp objects (like box cutters) are not left lying around. Immediately after use, cords and wires should be rolled up and put away to avoid accidental trips and falls.

2. Floors should be checked daily for spills and other potential hazards.

3. Racks should be inspected and replaced (as necessary), at least twice a year, as poorly maintained or damaged racks can cause injuries. Over time, racks may lose their support, due to minor collisions with a lift truck/forklift.

4. Forklifts can be very dangerous, if a few simple safety measures are not followed. First of all, no one should operate a forklift unless they are properly trained. A lift truck should never exceed 5 miles per hour, and a damaged truck should never be in use.

5. Empty pallets should have a designated storage area, and they should never be stacked more than six feet high.

6. Loading dock safety is an area that deserves a great deal of attention. Brightly colored tape and posted signs are excellent visual safety measures to use on any loading dock. In addition, the dock plate should never be overloaded.

7. Tight deadlines may lead to injury, and this is an important warehouse safety topic that needs to be addressed – how to manage employee safety and demanding delivery deadlines.

8. Conveyor belts are a common cause of employee injuries. Belts should be inspected daily and be maintained, as needed. A lockdown plan must be established and tested.

9. Hiring a warehouse safety specialist for an annual assessment of the environment is a good investment.

10. Dehydration is common among workers that spend hours in a hot warehouse. Management should always be on the lookout for fatigue among employees, and offer ample time to hydrate and cool down during a shift.

Laser Cutters and the Hobbyist

For many home hobbyists a home laser cutter or laser cutting system makes easy work of cutting precise patterns and etching into plastics, wood, rubber and other soft materials.

The laser cutting process produces extremely accurate clean, accurate cuts and is especially suitable for high-precision applications although more and more hobbyists are purchasing home laser cutting systems.

How Laser Cutting Works

A laser cutter works by the process of exciting a gaseous medium, most commonly, carbon dioxide to amplify light that gets reflected back and forth many times within the chamber of the laser. The light comes out of an aperture and is then focused by a lens onto a specific point.

A typical laser uses a beam 1/5 of a millimeter in width generating between 1000 to 2000 watts of energy that the laser focuses on a point to melt materials. Lasers lose focus and energy as they penetrate material so cuts are generally limited to a depth of 20 millimeters.

Laser cutting machines are integrated into larger CAD/CAM systems that takes a design file and implements the exact measurements, curves, lines and angles onto the workpiece eliminating the need for hands-on manufacturing.

Most laser cutters allow feautres as small as 1 millimeter in size and specialized laser cutters can achieve even smaller features that allow for the fabrication of micromachinery. Cutting lasers are classified as “class 4” lasers which means that the laser cutting machines are designed to ensure that all cutting occurs within the machine and human operators are never exposed to the laser beam directly.

What Materials Can Be laser Cut?

With many technological advances being made in the high power laser industry there has been a big increase in the types and numbers of materials suitable for laser cutting. Laser cutting can be used on materials with a variety of thicknesses.

Although laser cutting is more typically used on flat sheets, laser cutters can also cut cylindrical and other geometric shapes. Materials suitable for laser cutting include several types of plastics including acrylonitrile butadiene styrene, acrylics and high density polyethylene.

Laser cutters are used on mylar, nylon and polypropylene although these materials are more unpredictable in how they melt during the cutting process. Ceramics, certain grades of foam such as depron, gatorfoam and expanded polystyrene, paper, leather, rubber, magnetic strip, balsa and medium density fiberboard among other woods are also suitable for laser cutting. Finally several metals can also be cut using lasers and these metals include mild steel, stainless steel and aluminum.

Types of Lasers

There are basically three types of lasers used for cutting. The CO_2, the neodymium Nd, and neodymium yttrium-aluminum-garnet or Nd YAG lasers. These lasers do not work equally well on all materials so it is important to know what material or materials will be cut and whether or not the laser under consideration is suitable for the material.

It is always wise to consult with a laser- cutting engineer or manufacturer to understand what models are best suited to the cutting application in question.

Three Dimensional Laser Cutting

A three-dimensional laser cut is similar to a regular laser cut. The major difference is that the laser, in conjunction with a computer driven program can recognize all sides of a substrate material and not just the face of the material. 3D laser cutters are able to work on cubed materials or other large substrate shapes and not just flat materials.

The substrate material can include glass, crystal, metals and woods. In 3D laser cutting the laser can be programmed to cut the inside of the material as well as the surface. This is a common process in the cutting of crystal.

Hobbies Appropriate for Laser Cutting

Laser-cut art hobby products can be made in a variety of materials including wood, metal and paper. Types of art you can create include earrings, wall screens, wood furniture, cards, puzzles, toys, sculptures and more.

With advanced computer programs laser cutters can be used to create 3D models and artwork. Engraving is one of the most common uses for a home laser cutting system.

Hobby Laser Pricing

Home hobby Laser cutters can be bought for as little as $1,500 if you chose a cheap imported model but many of these cheap laser cutters lack features and do not come with clear, easily understood directions. They also tend to require new gas tubes more often than slightly more expensive professional grade laser cutting machines you can purchase for around $3,000-$5,000.

Safety should be a concern so it is always better to buy a professional standard machine. Imported machines may not conform to industry safety standards.

Cheaper models may work okay for two-dimensional laser cutting but if the machine will be used for sculpting or etching one should consider a professional laser cutting system with advanced features and computer numerical control (CNC) that easily handles complicated shapes and 3D Cutting.

CNC controls also which eliminates the need for manual operation and increases accuracy. CNC lasers are considerably more expensive but can be a worthwhile investment for a small home business.

Conclusion

Although it is easy to find home laser cutter systems for sale online or second hand at cheap prices it is important to carefully consider how the home laser cutting system will be used, safety concerns, and cutting materials. The hobby laser cutter must be appropriate for the materials it will cut and thought must be given to the degree of complexity and accuracy required for the production of the products.

The best advice is to seek the assistance of a qualified laser-cutting manufacturer to help identify the best laser cutting system for the type of cutting required as well as the materials that the laser will cut. Good research and information will save a lot of hassle, wasted money and frustration.

Check out our laser cutters for sale here

Finding The Best Sheet Metal Brake For The Job

This type of machine/equipment is used to bend metal into different shapes that are then used in auto body repair shops, ventilation systems, and by installers of windows and gutters.

Sheet metal brake machines can be large (weighting several thousands of pounds) or you can get a portable version, which is used by many window siding installers. Although a portable sheet metal brake (commonly misspelled – sheet metal break) is not as advanced as the larger version, it is more than effective to perform basic metal shaping needs.

Different types of sheet metal brakes for sale include:

Cornice metal breaks only allow for straight, simple metal bends to be created.
Box & Pan Brake (also referred to as a “bending brake” or a “sheet metal folder”). The advantage that this machine has over the cornice break is that the clamping bar is broken down to several blocks that are easily removable, and can be arranged to form a variety of shapes/bends along the piece of metal. The clamping that the box and pan metal break uses can be manually or automatically operated. Once the box is formed, it is secured together by screws and rivets or welded together.
Bar Folder brake machines are considered one of the simplest ways to bend metal. Typically, it is much smaller than the box and pan type or the cornice. The depth created by the folder sheet metal break is usually shallower than the aforementioned machines are capable.
Press Brakes are a more complicated version of bending sheet metal, as many pre-determined shapes can be created, by having the workpiece clamped between matching punch holes.

Sizes of used sheet metal brakes vary greatly, from hand-held versions made from light aluminum or brass, up to hydraulic sheet metal brake machines that are often used in large industries, to bend/shape large sheets of metal/steel quickly and effectively.

Basic components of a standard sheet metal brake:

BED – The bed is a flat area that the piece of metal is placed on, before processing can begin.
CLAMP PLATES are found sitting parallel to the “bed”, and holds the metal piece securely in place during the bending process.
A BAR/BENDING PLATE is attached to the bed’s edge by hinges.

As the brake press engages, the bar hinges moves upward, and bends the metal piece that is clamped between the “plate” and the “bed”. A measurement of 120 degrees is usually the angle of the bend. Certain variables (such as the thickness of the metal) will adjust this angle.

After the metal is formed by a sheet metal brake, it can then be coated with a clear finish or finished/coated with other options, such as a white, bronze, brushed gold or black anodized for a totally new look.

New or used sheet metal brakes are made from a variety of metals, including (but not limited to) brass, aluminum and stainless steel.

Material formed by break metal machinery is used for railings, column wraps, architectural detail and framing (just to mention a few).

Sheet metal brakes and the ability to bend metal is important to many industries and homeowners. Consider that it may not be necessary for a homeowner to invest in the many options of sheet metal brakes for sale, as many large tool companies rent sheet metals breaks to homeowners, whom may only need to replace a section of aluminum siding or a gutter.

CNC Router Machines & Kits

The difference between a CNC router machine and hand held router, is the fact that the tool follows a path via a computer control, instead of being guided by hand.

There are two software programs involved: CAD (which makes the designs) and the CAM (which communicates these designs to the machine).

This computer controlled machine is ideal for cutting a variety of material, such as steel, aluminum, plastic, foams, composites and wood.

The sizes and configurations of a CNC router vary drastically, from the small desktop version, to the industrial size – which is often used in boat and cabinet making shops.

Even though the sizes may differ, there are some CNC router parts that are common among all machines:

Controller

A CNC router machine is usually controlled via a computer and specific software, but it can also be controlled manually. On the control panel you may find a “reset” button, a manual control switch and a “stop” button for an emergency shut- down of the machinery.

Spindle

The spindle is the part of the CNC machinery that does the actual cutting. Spindles are categorized by their power output. The speed of the spindle is dependent upon the type of material being cut.

Linear Guides

Linear guides, also referred to as rail systems or linear block guides, basically leads the spindle in the direction of the axis, with little or no friction. The rail guides the blocks, and allows for a smooth ride as the load is moved.

Simply think of this concept as a roller coaster – the “rail” is the track, and the “block” being the cars traveling along the track.

CNC Router Kits

There are a few things to consider before purchasing a CNC router kit, and the first being the size needed for your project. For example, will you be cutting guitar shells from wood? Or building a canoe? Or processing the same template all day?

It is recommended to think about the largest piece you plan to cut, and to plan your router kits based on that measurement. In addition, the workshop area may also be a factor in your decision making process.

Some will come with a computer, while other kits will only have the software included. For this reason, it is important that you know your computer needs before making the purchase.

A quality kit should come with a variety of bits. In some kits, there will be a feature that will change bits automatically (but expect to pay extra for this convenient feature).

Before your final decision is made, it is important to notice the speed that is included within the CNC router kit. A slower machine may initially save you some money, but if you need to meet deadlines of large quantities of product per day – it may be more cost effective to purchase a quicker cutting machine. A slower CNC router is fine for a hobbyist, who is looking to save money and does not have a tight deadline to meet.

Final Word

A CNC router machine is a boring machine, panel saw and spindle moulder, all wrapped up in one great machine. It not only reduces waste and errors, but it allows a finished product to get into the public market, in a shorter period of time.

The products created with the assistance of this machinery are numerous, they include (but certainly not limited to): musical instruments, furniture, doors, frames, paneling and decorative carvings.

What is the Difference Between AC and DC Welding?

Arc welders use both AC and DC current. In order to make the best welds a welder must understand what alternating current (AC) and direct current (DC) signify on the welder as well as on electrodes. AC and DC are terms that refer to the polarity of the electrical current that is created by the welder and runs through the electrode.

The strength of a weld depends on selecting an electrode with the correct polarity because the polarity of the electrode can significantly affect both the strength of the weld as well as the quality of the weld.

What Is Welding?

Welding is a process used to join metals together by melting the parts and using a filler to form a joint. Welds can be accomplished using different energy sources from a gas flame or electric arc to a laser or ultrasound.

The welding processes used currently include arc welding which is done through the use of electrical current; gas welding which is most commonly used in the repair of pipes and tubes; resistance welding which uses additional sheets of metal to encase the workpieces that will be joined together; and energy beam welding or laser beam welding which is fast and accurate but very expensive.

Welding cannot be done with all types of metals. For example, stainless steel is prone to cracking and distortions when it is overheated. Alloys are often a problem because it is difficult to know the exact chemical composition of the metal.

An interesting fact about welding is that welding can be done under unusual conditions such as underwater and in outer space.

What Is Polarity?

Every electrical circuit has a negative and positive pole. Direct current flows in a single direction resulting in a constant polarity. Alternating current or AC current flows in one direction half of the time and in the opposite direction the other half. AC current changes its polarity 120 times per second with a 60 hertz current.

Electrode positive or reversed polarity (AC current) results in deeper penetration while electrode negative (DC) or straight current provides faster deposition rates because there is quicker melt-off of the electrode. There are different types of electrodes and electrode shielding that can alter these basic conditions. Some kinds of shielded electrodes function using either polarity while others only operate on one polarity.

In order to achieve proper penetration, uniform beading and good welding results the correct polarity must be used when welding with any given metallic electrode. Using incorrect polarity results in poor penetration, irregular bead shapes, excessive splatter, overheating, lack of arc control and quick burning of the electrode.

Most arc welders have clearly marked terminals or directions for how the welder can be set to either polarity. Some welding machines use a switch to change polarities and others require changes be made to the cable terminals.

Welding with AC Current

Welding with AC is ideal for the following types of welds:

Downhand heavy plate
Fast fill
Aluminum TIG welding with Hi frequency

Carbon arc torches have two types of AC current: a smooth arc for general purpose welding and a force arc for carbon arc, TG attachments and new fabrications.

Welding with DC is best used for:

Hard facing
Single carbon brazing
Build-up of heavy deposits
Stainless steel TIG welding
Cutting tap

DC Reverse Polarity

In DC reverse polarity the electrode is positive and the current flows from the workpiece to the electrode. Welding with reverse DC polarity is ideal for:

Overhead welding
Vertical welding
Cast iron welding
Heavy aluminum
Rivet welding
Sheet metal
Low hydrogen welding
Arc bronze rod

Advantages of DC Welding

When it comes to stick welding applications DC welding offers certain advantages over AC. Generally, starts are easier, there are fewer arc outages and sticking, there is less spatter, welds have a better appearance, welding vertically or overhead is much easier and DC current is the best ways for beginners to learn “how to weld”. DC welding also provides a smoother arc and DC straight polarity welds a lot of thinner metals better than AC.

Advantages of AC Welding

The main advantage of AC output welding is that it enables one to weld on magnetized materials because the current alternates between polarities. DC output does not work on magnetized materials because of “arc blow” which is when the magnetic field blows molten filler metal out of the weld puddle.

Welding Machines and Safety

Many cities and states require welders to be trained and certified in order to operate welding machines. There are also requirements for personal safety equipment and fire-prevention measures that welders must follow.

Welding fumes can cause breathing problems in welders. Some problems are short term and others may be long term illnesses like asthma. Welding fumes are also internationally classified as possible carcinogens. There are specific methods for reducing the exposure to fumes. Contact OSHA or the American Welding Society for more information.

Burns are probably the most common injury associated with welding. Personal protective clothing can significantly reduce the risk of burns. Personal protective equipment for welders includes fire-resistant clothing, safety glasses, shoes, gloves, hood and welding helmet and leathers. Synthetic clothing should never be worn because it melts when exposed to extremely high heat. Wool is a better choice because it is durable and resistant to fire.

Pants and shirts should not be rolled up because sparks can get deposited in the folds. Pants should also be worn outside of shoes or work boots to protect particles from falling inside the shoes or boots. Safety goggles should always be worn under the welding helmet. If safety glasses are used instead of goggles they should also have side shields.

Conclusion

AC And DC welding are both needed to accomplish certain tasks. DC welding generally has more advantages over AC welding but the most important thing for a welder to understand is how polarity works so that the welder can choose the proper electrode with the right polarity for the job.