How to Increase the Process Speed of Die Sinking EDM

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Developments in the EDM process and its technology along with improvements in accuracy, automation and micro-mold making technology can pay enormous dividends to the domestic mold making industry.

 

Speed Is Not the Solution

Increasing drive speed is one solution to improving the speed of die sinking EDM. In this way the unproductive times for lifting movements are reduced; however, the gain in speed is limited to small electrodes and very deep cavities. In addition, above a certain speed the electrode wear is considerable and very high axis speeds result in extreme strain on the mechanism, make the machine more expensive and shorten its working life. Therefore, it is wrong to believe that a general increase in the process speed is only to be achieved by rapid lifting movements. The contribution of fast axes to the machining process is just one supplementary aspect to a complex interaction that encompasses the generator, process control, gap width regulation and the mechanism. And die sinking EDM requires intelligent flushing.

 

Potential Lies in the Flushing

You can imagine the EDM process as being a balance between the EDMed and evacuated material in the gap. If this balance is not present, then either you flush the machining area unnecessarily—involving a loss of time and additional instability of the process—or you EDM the same particles several times, which cannot be removed from the gap sufficiently.

 

Die Sinking EDM

Before the material can be evacuated from the gap you must remove it from the workpiece. So how can you achieve more removal? As in the case of all optimization problems, the greatest gain potential lies where the efficiency is smallest. The efficiency of a single discharge with a cathodic poled workpiece is theoretically about 25 percent.1 In addition there are some factors that make the efficiency even worse (e.g., process control problems, non-ideal flushing conditions, small gap width), so that realistically you must reckon with an efficiency of less than 10 percent.

 

Removal and Surface Quality Determine the Time Requirement

In the case of EDM, the objective is always to optimize the removal performance of the machining on one hand, and to achieve the surface quality of the workpiece to be machined on the other hand. The workpiece, when machined, is intended to display a certain final roughness and a certain form precision. In addition, two conditions are called for:

 

  1. As small a thermally influenced area of the workpiece surface as possible
  2. As low an electrode wear as possible.

 

These marginal conditions determine the machining time and costs for workpiece production. In practice, a sequence of technological parameters is used because starting out from the roughing to finishing settings, the pulse energy is gradually reduced until the required technological results are achieved. Once again the law of nature applies: you can quickly achieve results of modest quality, but only slowly results in high quality.

 

Physical Processes Show a Solution

The approach toward an ideal state means moving the characteristic curve in the direction of the arrow. That means faster EDM with the same gap width, roughness and wear. If, up to now, the discharge energy of the EDM pulses was increased, regrettably you also only had greater roughness and a greater gap width so that the gains in speed during roughing were lost again through longer finishing. You will find a way to a solution if you return to the basics of EDM theory—to the physical processes leading to the formation of the spark and metal removal.

 

During the discharge, you can identify three main physical phases in succession:

 

  1. The Build-Up
  2. Discharge
  3. Fade Phases

 

In the first phase the discharge canal is built up. After passing through the working medium, the current flows almost exclusively on the surface area of the discharge canal and the anode is partially evaporated by the electron bombardment. The electrode wear mainly takes place here. Every pulse—whether contributing intensively to removal or not— causes microscopic wear. In the discharge phase, the electrical energy supplied causes melting or evaporation of material mainly on the workpiece. The fade phase begins with the switching off of the power supply. The plasma canal collapses and the partially evaporated, partially liquid material is ejected.

 

When to Interrupt Pulses

During the discharge, a crater forms in the workpiece. Fundamental studies of discharges have shown that the growth of the crater in the workpiece stagnates from a certain time. This is because a balance forms between the energy supplied and the energy lost, as well as energy that is used for the maintenance of the plasma and the heat loss to the workpiece and dielectric. This asymptote of the crater growth can be recorded in real time from the spark voltage and current.

 

However, why is the asymptote of the crater growth so important? Because this is the right moment to interrupt the pulse. It is unnecessary to let a pulse last longer if the target radius of the crater and the required roughness have been achieved. You can begin with the next pulse immediately. The time required by the pulse to reach this state also is not constant, as the speed with which a discharge reaches a certain spark base diameter depends on the macroscopic situation in the gap and the local geometry in the spark discharge area. With this first measure alone, you will optimize the number of discharges per unit of time and increase the removal rate.

 

When to Increase the Current

If you now observe the charge’s fade phase you will see that the removal from the workpiece is caused by the collapse of the plasma canal. The sudden drop in pressure—triggered by switching off the power—causes the evaporation and ejection of superheated material. The plasma canal has a very high temperature and pressure. The gradient of its collapse influences material removal. The more abruptly the energy disappears, the better the crater material will be ejected. In order to enhance this effect, a special trick is employed: before the pulse is interrupted, the current is increased briefly. The idea of increasing the pulse current is not new, the innovation is the definition of the point in time when this increase is to take place. The increase in the pulse current has no consequences for the roughness, wear or gap width, but does increase the removal. In addition, as the removal per pulse is greater, you need fewer pulses for the machining, and therefore the wear sinks.

 

Removal Rate Doubles in Part

This new machining strategy (asymptote detection, current increase and pulse interrupt) is the subject of a patent application for its use in new EDM die sinking systems. The results are in accordance with the theoretical reflections, especially where good flushing is guaranteed (e.g., pre-machined workpieces). For these machining jobs removal rates have doubled.

 

Generator Brings Striking Improvements in Performance

The innovative generator offers an increase in productivity of approximately 30 percent; however, up to 100 percent with pre-milled molds that occur increasingly nowadays through synergies with HSM. This refers to all roughing and finishing using copper and graphite electrodes. The advantages are particularly great with good flushing conditions and pre-milled workpieces. These convincing results explain that it is possible to increase the speed and productivity of die sinking EDM, and the potential for improving this technology is still considerable.

 

If you need more information about die sinking EDM, please try to visit the website of Excetek Technologies Co., Ltd. – the company is the well-known brand for its EDM machines. Get more details about Excetek, welcome to check out their product pages and feel free to send inquiry to them.

 

Article Source: MoldMaking Technology

Five Reasons to Use an Automatic Liquid Filling Machine

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Automation in the packaging process creates many benefits for the packaging company. Here we will analyze individual pieces of packaging equipment and explain some of these benefits.

 

The automatic liquid filling machine moves product from a holding tank to the waiting bottles or other containers without the need for operator interaction during each fill cycle.  In automating the filling process, a company can expect to improve the packaging operation in a number of ways, including, but not limited to, the following.

 

  1. Consistent and Reliable Fills

 

Using automatic filler removes the uncertainty from the filling process. Whether looking for a level fill, a highly accurate volumetric fill or using some other specific criteria, the automatic machine ensures that each cycle is completed in the same manner. Consistency and reliability that simply cannot be had by hand filling bottles or containers is easily achievable with the right machine for each project.

 

  1. Speed

 

Once production demand reaches a certain level, it simply becomes unrealistic to hire manual labor to complete each bottle fill. Probably the most obvious benefit of using automatic packaging machinery is the ability of the machinery to increase speeds. Using power conveyors and multiple fill heads along with the proper filling principle allows production to not only run faster, but run constantly.

 

  1. Versatility

 

Many companies use multiple bottles for a single product. A number of companies also run multiple products. In most cases, single liquid filler can be manufactured to handle all bottles and products packaged by a company. Some machines will use simple adjustments to change from one bottle or product to another, while others might require a little more time on changeover where bottle sizes or product viscosity varies greatly from one to another.

 

  1. Ease of Use

 

Almost all automatic filling machinery will come equipped with a PLC and easy to use operator interface. The interface uses a touchscreen that allows the operator to enter the various times and amounts necessary to complete each cycle. Once the numbers are entered, a recipe screen will allow the same to be retained. Eventually, the operator will simply need to enter the recipe number on the interface, make any physical adjustments (conveyor rails, fill head height, etc.) and then monitor the machine as it goes to work.

 

  1. Growth Potential

 

Automatic packaging machines can and should be manufactured with the future in mind. In other words, the machine should not be manufactured to immediately meet maximum capacity. At LPS, we build our equipment expecting our customers to experience growth! Simple additions to filling machines, such as extra fill heads, allow the equipment to grow with the business.

 

While there are other benefits to automating the filling process from project to project, a packager can always expect to receive those noted above.

 

Get more details about automatic liquid filling machine, welcome to visit SHIN I Machinery Works – the company is always your best cooperation partner for packaging equipment machinery.

 

 

Article Source: https://www.liquidpackagingsolution.com/news/five-reasons-to-use-an-automatic-liquid-filling-machine

Something Should Be Understood Before You Buy Permanent Makeup Machines

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How Is Permanent Cosmetic Makeup Applied?

There are a variety of ways that permanent makeup cosmetics can be applied. Many men and women explore permanent makeup machines to get permanent eyeliner as well as lip lines. Cosmetic professionals sometimes use tattoo coil machines; rotary, digital or pen machines; or just by hand.

 

Generally a permanent cosmetic makeup artist will consult with a client about what they’re looking for. When they have agreed on goals, the permanent cosmetic artist will supply pigment and do the actual cosmetic tattooing.

 

Follow-ups are required to touch up the makeup, ensuring that the design and color of the pigment is maintained.

 

Who Is Permanent Make Up For?

  • Permanent makeup can be a good idea if you do not have any eyebrows
  • People that suffer from allergies and skin sensitivities
  • Highly active people involved in sports that don’t want to sweat off their makeup and have to reapply it
  • Vision-challenged people who love make up but can’t apply it themselves
  • Individuals suffering from dexterity-related issues like Parkinson’s disease, multiple sclerosis, arthritis and stroke can also benefit from cosmetic tattooing
  • Highly busy people that just don’t have the time to spend making up their face every morning and evening

 

Is Permanent Makeup Safe?

Most trained cosmetic professionals are certified by the Occupational Safety and Health Administration and use proper sterilization and disinfection. Some of the important criteria include the use of new and sterile needles for each client.

 

Disposable aprons and gloves should be used for each client. A technician should also adhere to high hygienic personal standards.

 

The bed and chair covering should be disposed after each use and the treatment room should be kept clean at all contaminants.

 

What Are The Side Effects Of Permanent Makeup Application?

Commonly eyebrows do not demonstrate any ill after effects from treatment. However there may be moderate swelling if you have eyeliner and lip make up permanently applied. This will, of course, depend on your own sensitivities as well as the extent of the work was performed.

 

For example, merely having lip liner permanently applied will show more minor aftereffects than if you had full color permanently applied. Everybody is different-and skin sensitivities very greatly between clients. Bruising can also occur but is generally fairly minor and commonly subsides in a couple of days. Tenderness is also another common symptom that also will fade with time.

 

A common concern is that the color initially will be here much sharper than anticipated but it will normalize within the first 6 to 10 days.

 

Where Can You Find The Permanent Makeup Devices?

If you’re looking to purchase a permanent makeup machines, try to visit the website of Bella Co., Ltd. – the company is specializing in a variety of permanent makeup devices and accessories. Get more information please do not hesitate to check out their product pages and send inquiry to Bella.

 

 

Article Source: Top5Reviewed.com

Get Some Information About Bubble Cage Before Buying…

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Why Do You Need Bubble Cages?

Blown film extrusion is the process that involves extruding a tube of molten polymer through a Blown Film Die (Single or Multi-Layer), which is a vertical cylinder with a circular opening. Air is injected through a hole in the center of the die creating a bubble, several times its initial diameter. The bubble is pulled upwards and an Air Ring blows air onto the film to cool.

 

Bubble cages reduce the turbulence caused by the cooling air stream when it hits the bubble. The Bubble Cage reduces movement that the bubble would otherwise have and prevents the bubble from losing stability. More stability results in increased production as well as improved quality.

 

Recommend Bubble Cages Supplier

If you have any interest in Bubble Cage, I recommend that you can visit the website of Hsin Long Thread Rolling Machine Co., Ltd.

 

Hsin Long Bubble Cage

Hsin Long Bubble Cage

 

  • The wires of stabilizing ring with SUS304 for increased.
  • Easy to adjust.
  • Single or double layer assemble easily.
  • Mass production, competitive prices.
  • Choice of various ring diameters.

 

Learn further details about bubble cage or other blown film extrusion machine, please do not hesitate to check out Hsin Long product pages and send inquiry to them.

 

 

Article Source: Mark One Machinery

Let’s Talk About SUP Leashes

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SUP leashes provide a simple and secure way to keep a paddler with their board. Wearing a leash should be second nature, like wearing a seat belt in a car. But do you know about the different types of leashes, and understand when and where they should be used?

 

History of The Leash

Invented around 1970 the surfboard leash started off as a very springy and often dangerous way to prevent a board making its own way back to the beach. The equipment we now regard as essential to safety may have been responsible for Jack O’Neill losing his eye in 1971 from a ‘whiplashing board’. Not the best start for safety equipment!

 

The use of urethane for the leash became commonplace in the mid to late 1970’s reducing the whiplash effect (but not removing it) and making them far more durable. According to some sources (Surfer Magazine, 2011) 99% of surfers use one. Even with such apparent support for the use of leashes there are surfing applications where their use is questioned. The loss of Mark Foo at Mavericks in 1994 has been blamed on his leash and that discussion continues today.

 

For SUP use the urethane leash has been beefed up a little to cope with the larger boards and higher volumes. But they look just like standard surfboard leashes so when buying one make sure it’s suitable for your board.

 

Types of SUP Leashes

There are two types of leash, coiled (commonly used for flat water), and straight (commonly used in surf and other general paddling) both typically fit around the ankle or calf. However these leashes are also available with a quick release mechanism which then typically attached to a belt worn around the waist, allowing for quicker and easier release from your board (commonly used in moving water and also now popular when racing)

 

Straight Leash

This type of leash is ideal in the surf, because it has less spring back than a coiled leash (and therefore less chance of your board coming back and hitting you in the face!) and it trails in the water leaving your deck clear to move your feet around the board. Ideally a surf SUP leash should be at least the length of your board. A straight leash is the most universal leash as can be used in not only surf but also flat water and moving water (with a quick release attachment). So if you want one type of leash to use on flat water and in the surf then get yourself a straight leash.

 

Coiled Leash

These are most commonly used in the flat water SUP and race scene. Sitting comfortably on the deck out of the water, they produce less drag and reduce the risk of getting caught on seaweed, and other paddler’s paddles etc.… Not for use in the surf due to their spring back board potential! If you do use a coiled leash in the surf (not recommended) you can guarantee it won’t be coiled for much longer!!

 

Quick Release Leash

The quick release is an attachment that can be added to any standard straight/coiled leash, or you can buy a specialist quick release leash. Gaining in popularity the quick release leash is worn around the waist as a belt, either on it’s own or as part of a buoyancy aid/hydration pack. The quick release is a buckle, usually with a toggle attached to it so it can be grabbed quickly and pulled open, releasing the paddler from the board almost immediately. Probably developed from harnesses used by White Water kayakers this type of leash is starting to appear on the race and surf race scene too. When racing it eliminates any chance of the leash dragging in the water, keeps it out of the way when stepping back for buoy turns and moving around the board, and allows for quick and easy board transitions during races.

 

In white water a quick release leash is vital in the event of a situation when you need to separate from your board quickly e.g. becoming held by the water against an underwater obstacle. Therefore when white water paddling a quick release leash is essential.

 

How to Attach A Leash

The vast majority of boards will come with one or more specific leash attachment points, usually found near the tail of the board. On an iSUP this is likely to be a steel D ring glued to the board, on hard boards they are often recessed into the deck. Leashes will usually come with a length of string attached to a rail saver. The string is the connection between the board and the leash.

 

Surf SUPs will typically have one leash attachment point at the tail, but longer, race boards frequently come with a leash attachment point in front of the deck pad allowing a shorter leash to be used and reducing the chance of it dragging in the water.

 

How to Look After A Leash

Leashes will have a hard life! As well as being stretched, on an iSUP they are frequently looped around a rolled board to keep everything tidy, and on hard boards you’ll see them wrapped around the tail when in transit. Doing this can develop kinks in them and the urethane can easily be damaged. Therefore urethane leashes should, when not in use, be removed and kept out of the sun. It’s worth storing your leash with your board so there’s no chance of forgetting it.

 

Your leash is the most important bit of safety equipment you have, so check it regularly for any signs of wear and look after it. They’re not cheap, but a leash is there to save your life, so if you think it’s starting to look a bit tired and needs replacing – then replace it. Don’t just wait for it to snap!

 

When to Use A Leash?

The simple answer is always. End of discussion.

 

But nothing is that simple, using the wrong leash can be more dangerous than not wearing one at all.

 

In the sea, SUP surfing, a SUP leash is a necessity not an accessory. And the vast majority of SUP surfers will wear a leash without hesitation. But using one is not the end of the SUP surfers’ responsibility. A big board at the end of a long leash could do a lot of damage in a crowed line up. And in the surf, a SUP board of any size on the end of a coiled leash is asking for trouble too! Always consider the safety of others in the water, as well as your own safety.

 

For coastal exploration or flatwater paddling a leash makes sense most of the time, they are comfortable and don’t get in the way, and keep you connected to your board (flotation device). However a big flat river can have a strong current and be moving a huge volume of water, just like in a WW river. UK rivers are often not clear water, carrying silt which means that obstacles under the water e.g. tree branches etc.… are not always obvious. Leashes can easily be caught around these objects as well as pontoons, jetties, buoys etc.…

 

So sometimes undoing a leash would be a good idea whilst paddling, for example when getting on or off a board at a pontoon with a strong current. Better to undo your leash and climb out with the risk of losing your board, rather than getting pinned and losing your life.

 

No matter how you look at it, a Velcro strap attached at one extremity of your body is not an easily accessible quick release. Have you ever tried reaching your ankle against fast flowing water? Not much fun and near impossible.

 

So is the future of the SUP leash around our waists? Any leash can be converted to a waist leash with quick release so it would seem to be the sensible thing to do for all but SUP surfing.

 

If you need more information about sup leashes, please try to visit the website of BroadPlast. The company offers a wide range of kayak accessories including kayak fishing accessories, deck hardware, handles, sup leashes, bungee and bungee connections, fasteners as well as some other marine hardware. Get more options, welcome to check out BroadPlast product pages and send inquiry to them.

 

Article Source: SupBoarderMag.com

What Is A Spanner Wrench?

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Maxclaw Hook Spanner Wrench

A wrench is a tool that provides a grip for tightening or loosening a fastener, such as a nut or bolt. The term spanner wrench is redundant; Americans consider this kind of tool a wrench, while the British refer to this tool as a spanner. While there are many kinds of wrenches, Americans refer to the type of wrench that contains pins or tabs around its circumference as the spanner wrench. These wrenches are made of steel for strength and are often chrome-plated to protect against corrosion.

 

There are many types of spanner wrenches, each with a distinctly shaped hook. In addition, some spanners are multi-tools with double-sided hooks. The most common type of spanner wrench is the C spanner. Its head is open in the shape of the letter C, and its jaws are meant to correspond to the similarly sized nut. The obstruction spanner is similar to the C spanner, except its jaws are angled more steeply to enable you to reach nuts in confined spaces. The ring spanner, on the other hand, has a completely enclosed ring that fits precisely over a hexagon or square bolt. While it can take some time to correctly place the ring spanner, it provides stronger leverage than open spanners. Make sure your spanner wrench is the correct size and is sitting properly around the nut before twisting. Otherwise, it could slip from the wrench and damage the tool or injure your hand.

 

Spanner wrenches are often used in plumbing to help repair leaky pipes or faucets. They are smaller and lighter than pipe wrenches, allowing flexibility to work in hard-to-reach areas. In addition, they provide enough turning force to open pipe connections that have been untouched for many years. Similarly, spanner wrenches are commonly used in gas repair to open gas pipes.

 

If you need more options of wrenches, please do not miss Maxclaw Tools Co., Ltd. – the company can provide basin wrench, hook spanner wrench, plumbing wrench, and drum wrench series for you. Now, check out Maxclaw’s product pages to get your right wrench!

 

Article Source: https://home.howstuffworks.com/spanner-wrench.htm

How to Specify and Apply Precision Gearboxes with Servo Systems

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A servo system and gearbox can provide precise motion control, but care must be taken in design, selection, and implementation.

 

With the many industrial gearboxes available today, it’s important to match the proper type of gearbox with the drive, motor, and load. When a machine needs a servo system (drive and motor), the gearbox type is critical for accurate and repeatable motion. Planetary gearboxes fit the bill for servo applications.

 

High-precision helical planetary gearboxes are an excellent choice for applications that need accuracy and reliability. Planetary gearboxes have very low backlash ratings (typically ranging from one to nine arc-min), and when sized correctly offer a service life of over 20,000 hours with virtually no maintenance. Helical planetary gears also provide very quiet and more efficient operation as compared to competitive products.

 

Precision gearboxes are carefully machined to high tolerances – think clockmaker, not blacksmith. They offer power densities that translates to small package size and efficiencies of 90% and greater.

 

Why Use A Gearbox?

Servo motors often drive loads directly without the need for a gearbox, but in many applications it’s advantageous to use a gearbox between the motor and load.

 

One main reason to use a gearbox is torque multiplication. It lets designers use smaller servo systems that consume less energy. Instead of buying relatively large servo drives and motors, designer can use smaller components, saving space and money.

 

Output torque increases in direct proportion to the gear ratio, and top speed of the output shaft decreases. If an application can withstand the reduced speed, a relatively small servo system can supply high torque.

 

Gearboxes can also address inertia mismatches. For high performance servo systems — those with high dynamic responses or low overshoot, for example – the ratio between the reflected load inertia and motor inertia should be as low as practical, ideally under ten-to-one. A precision gearbox reduces the reflected inertia by the square of the reduction ratio. For instance, using a 25:1 gearbox reduces the load’s reflected inertia by a factor of 625, a significant improvement.

 

In some cases, gearboxes simply resolve issues relating to mechanical fit. For example, if directly mounting the motor interferes with another mechanical component, a right-angle gearbox may solve the problem.

 

Compared to most other gear reducers, a precision gearbox provides better accuracy and repeatability. Furthermore, the gearbox’s high efficiency lets it deliver maximum power available from the servo system—features often a necessity in servo applications.

 

Comparing Types of Gearboxes

 

Gearboxes use a variety of power-transmission methods including, but not limited to, planetary gears, worm gears, spur gears, helical gears, and shaft-mount gear units. In servo applications, planetary gearboxes are often the most suitable.

 

Worm gears use a worm or screw gear to turn a larger transverse gear. They can provide high gear reductions in small packages but aren’t that efficient, on the order of 70%. Worm gears aren’t reversible either and thus can’t be back driven, so they cannot be used to increase speed.

 

Spur gears use straight-cut teeth on parallel shafts for power transmission. They are available in a wide range of ratios and are cost effective, but they can be noisy and prone to wear.

 

Helical inline gearboxes also use gears on parallel shafts, but the teeth are cut in helical shapes to allow gradually increasing contact between mating teeth.

 

Helical inline gearboxes and spur gears typically have more backlash than planetary gearboxes, and there is undesirable thrust acting along the gear’s axis. Helically cut gear teeth are quieter and are used in other types of gearboxes because of this.

 

Shaft-mounted gear units are popular for parallel shaft gears, such as spur and helical gears. They are well suited to conveyors and other material-handling applications, and are easy to mount. However, they suffer from the same disadvantages as their constituent parts.

 

Planetary gearboxes are named for their resemblance to a simple solar system. They consist of a ring gear, several planet gears, and a sun gear. The ring gear is typically fixed and is often part of the gearbox’s outer casing, and the input shaft drives the sun gear.

 

Rotation of the sun gear drives the planet gears to spin about their own axes and revolve about the sun gear. A carrier attached to the planet-gear shafts harnesses output. This arrangement creates a balanced and compact design that is concentric about the shaft. If multiple stages are needed, it is relatively simple to connect the output of one set of planet gears to the sun gear of a secondary stage.

 

High efficiency, low backlash, and high power density make planetary gearboxes the best of these alternatives in high-precision servo system applications.

 

Selecting Gearboxes and Servo Systems

 

A servo system coupled with a planetary gearbox is expected to provide precise motion, but this requires all components be carefully matched. Although it’s possible to buy the servo drive, motor, and gearbox from different suppliers, it’s not recommended as this requires a great deal of research and comparison to ensure all components will work together. Purchasing components from a single supplier — especially one that has carefully matched the components and will stand behind the specific combination of parts in question—offers several advantages.

 

The supplier has done all the research and confirms compatibility. Most suppliers will extend a more favorable warranty on such purchases. Plus, they can provide the approved mounting hardware to connect the components.

 

Some suppliers provide online tools for selecting servo systems and compatible gearboxes, easing the specification effort. These selection guides aid the design and provide specific recommendations for closely matched components that can be purchased as a system. In these cases, engineers can be certain the systems they specify are compatible in all critical areas, and that the components will come with the required mounting bushings and keys.

 

In fact, some selector tools let designers enter their torque and speed requirements, and then automatically filter a list of available motor-and-gearbox sets. Engineers can enter torque data in metric or imperial values, or the designer can select a particular servomotor size. Designers enter speed data as discrete values, or pick a gear ratio. Finally, the engineer can choose a preferred physical orientation—inline, right-angle gearing, or both.

 

The resulting list of available systems includes pricing information, a factor often critical to the selection process. After choosing a motor/gear combination, the designer moves to a page with full specifications for the selected servo system, the gearbox, and the combination.

 

One caveat: Even though a selector can make the specifying process easier, engineers and designers should always verify that a system meets their needs and gets applied correctly.

 

Best Practices and Common Pitfalls

 

Although gearboxes help reduce mismatches between the motor’s inertia and that of the load, the gearbox’s inertia must be included in the calculation:
Best Practices and Common Pitfalls
When high dynamic responses are required, engineers need to carefully tune the servo systems, preferably with loads attached, for the most responsive performance. Tuning can provide faster moves and minimize spongy motion while reducing overshoot or ringing after moves is complete.

 

Designers must also pay attention to radial-load and axial-thrust-load specifications. Axial-thrust load is the force acting along the output-shaft axis; radial load acts perpendicularly to the output shaft.

 

The force of gravity acting on the load is perhaps the most common source of radial loads, but other sources are possible, depending on the mechanical apparatus attached to the output shaft. Additional external bearings may be required with some loads to minimize these forces and prolong the life of the gearbox’s internal bearings.

 

A common way to minimize backlash is to approach all target positions from a common direction. In the event a reversing move is required, some designers let the load go past the desired position and return to it from the common direction.

 

Gearbox Applications

 

One classic example of a precision gearbox application is an indexing table with several stations for machining or assembly. Precision gearboxes and servo systems fit well when the table is relatively heavy and needs to be accurately positioned and when high-speed operation is not as important.

 

In this case, the gearbox is being used simply for accurate torque multiplication. The servomotor’s top speed of 3,000 to 5,000 rpm is not required at the load, so the gear reduction ratio and corresponding torque multiplication can be large. This allows a relatively small servo system to handle the task. The servo system might even use its built-in indexer to control the motion based on discrete I/O signals from a PLC, or even a simple selector switch, depending on the required level of automation.

 

Another example of a gearbox application is a high-speed pick-and-place device, such as part removal from an injection-molding machine. The cycle time of these machines is often critical to meet production quotas, and the designer typically wishes to remove parts as quickly as possible after the mold opens.

 

The moving arms of the pick-and-place device are designed to be as lightweight as possible, but inertia mismatch can still be a factor. The gearbox can minimize the mismatch so that the pick-and-place mechanism is extremely responsive.

 

The PLC in this example might be much more involved in controlling the motion, commanding moves with pulse and direction signals. In some cases, the PLC also passes recipe tuning values to the servo drive when the motion profile or the picked-part’s inertia changes.

 

Precision gearboxes and servo systems can be used to meet a wide range of automation challenges. Machine builders should purchase the required components from a knowledgeable vendor who will stand behind their products. Using online selection tools can simplify the choices, although the system will require tuning after installation. When properly designed, specified, and tuned, these systems provide accurate, repeatable results for many years.

 

If you need more information about planetary gearboxes, please do not miss the website of JIA CHENG Precision Machinery Co., Ltd.

 

The company can provide high quality and precision reducer, gearbox, and coupling for you. Feel free to send inquiry to let JIA CHENG know your requirements.

 

Article Source: MachineDesign

An Introduction to Unmanned Aircraft Systems

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Unmanned Aircraft
Unmanned Aircraft Systems (UAS) are a new and evolutionary component of the aviation system, offering several new and exciting opportunities, as well as a number of challenges.

 

Unmanned aircraft come in a variety of shapes and sizes, ranging from small handheld types up to large aircraft, potentially a similar size to airliners and, just like manned aircraft, and they may be of a fixed wing design, rotary winged, or a combination of both.

 

Unmanned Aircraft may also be referred to as:

 

  • Drones
  • Remotely Piloted Aircraft Systems (RPAS)
  • Unmanned Aerial Vehicles (UAV)
  • Model Aircraft
  • Radio Controlled Aircraft

 

Regardless of the name used, they all share the common characteristic that the person responsible for piloting the aircraft is not onboard it. Just like any other aircraft however, an unmanned aircraft must always be flown in a safe manner, both with respect to other aircraft in the air and also to people and properties on the ground.

 

Types of Operation

The key first principle when discussing the regulation of any UAS is to determine how it is being operated and what process is being used to avoid it colliding with other aircraft, objects or people, which is the primary responsibility of anyone who flies any aircraft.

 

UAS are either operated:

 

Within the Visual Line Of Sight (VLOS) of the person flying the aircraft

This means that the aircraft must be able to be clearly seen by the person flying it at all times when it is airborne. By doing this, the person flying the aircraft is able to monitor its flight path and so manoeuvre it clear of anything that it may collide with.  While corrective spectacles can be used to look at the aircraft, the use of binoculars, telescopes, or any other image enhancing devices are not permitted.

 

In simple terms, the aircraft must not be flown out of sight of a human eye.

 

Beyond the Visual Line Of Sight (BVLOS) of the person flying the aircraft

If the person flying the aircraft is unable to maintain direct unaided visual contact with it while it is airborne, then an alternative method of collision avoidance must be employed in order to ensure that it can still be flown safely.

 

BVLOS flight will normally require either:

 

  • A technical capability which is equivalent to the ability of a pilot of a manned aircraft uses to ‘see and avoid’ potential conflictions – this is referred to as a Detect and Avoid (DAA) capability
  • A block of airspace to operate in which the unmanned aircraft is ‘segregated’ from other aircraft – because other aircraft are not permitted to enter this airspace block, the unmanned aircraft can operate without the risk of collision, or the need for other collision avoidance capabilities
  • Clear evidence that the intended operation will have ‘no aviation threat’ and that the safety of persons and objects on the ground has been properly addressed.

 

What Is The Purpose of Your Flight?

Your flight will broadly fall into one of three types as follows:

 

  • Recreational – where the flight is being conducted as a pastime purely as an ‘enjoyment’ or sporting activity
  • Commercial – where the flight is being conducted for business purposes in return for specific remuneration or other form of valuable consideration.
  • (a specific definition of a commercial operation is contained within the ‘Commercial Operations with Small Drones’ section)
  • Private/Non-Commercial – flights that are either:
    • not considered to be recreational
    • flown for business purposes, but without any remuneration or other valuable consideration being involved

 

While the regulations are the same for all types of flight, there are some specific additional requirements placed on commercial operations involving small unmanned aircraft.

 

If you want to learn more information about unmanned aircraft systems, please do not hesitate to visit Carbon-Based Technology Inc. – the company is specializing in unmanned aircraft / unmanned aerial system. Get more details, welcome to send inquiry to let Carbon-Based know your demands.

 

Article Source: https://www.caa.co.uk/Consumers/Unmanned-aircraft/Our-role/An-introduction-to-unmanned-aircraft-systems/

Something You Should Know About Rubber Oil Seal…

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What is Rubber Oil Seal?

 

If you ever notice dark smoke coming from the tail pipe of your car, chances are the rubber oil seals in your vehicle are leaky. The rubber oil seals are also called as oil seals, car oil seals, automotive oil seals and oil seal rings. Leaky oil seals fail to prevent liquids and gases from escaping, and thus oil begins to leak into places in your vehicle where it is not supposed to be. For instance, oil enters the fuel mixture and burns, resulting in the smoky combustion. Thus, we see that these rubber oil seals or oil gaskets are nothing but components that fit on valves and pipes for sealing oil inside the required compartments in your vehicle. Their design features a flexible lip that rubs against a shaft or housing and prevents the leakage or ingress of fluids and dirt from/ into the sealed compartment.

 

Advantages of Rubber Oil Seals:

 

Now rubber oil seal rings perform two important functions: they hold the oil in place, lubricating the moving machine parts, thus reducing friction, grinding and heat in the process. Additionally, these car oil seals keep foreign contaminants from entering and ruining the oil in your car. However, though these automotive rubber seals are popularly referred to as “oil seals”, they are used to retain or confine any form of fluid inside a particular device, especially devices such as hydraulic systems that feature a host of moving parts.

 

Types of Rubber Oil Seals:

 

  • U-Ring Seals
  • V-Ring Seals
  • Rotary Oil Seals
  • Labyrinth or Clearance Seals
  • Bearing Isolators
  • Spring-Installed Seals

 

Why Rubber is the Preferred Material for Oil Seals?

 

Though oil seals also come in materials like plain felt, leather and metal, the best ones are the oil seals made of different varieties of rubber. Seals fashioned from Nitrillic rubber is used with mineral oils, grease, diesel and water. Polyacryllic and silicon seals on the other hand are used for sealing motor oils, while flour elastomer rubber oil seals that have the capacity to withstand a wide range of temperature are normally used in different variety of fuel-related oils. Enlisted below are a few reasons that make rubber the most suitable material for manufacturing oil seals or oil seal rings:

 

  • Can easily withstand high temperature and pressure.
  • Have superior ozone resistance.
  • Feature excellent mechanical strength.
  • Can be easily shaped into different contours and patterns.
  • Are comparatively easier to install.
  • Require less maintenance and provide years of hassle free service.

 

Factors to Consider While Buying Rubber Oil Seals:

 

  • Type of polymer used in manufacturing
  • Shaft outer diameter
  • Seal inner diameter
  • Maximum operating speed
  • Maximum operating temperature
  • Maximum operating pressure
  • Vacuum rating

 

Are you going to look for the high quality rubber oil seals manufacturers and products? I recommend that you can try to visit Chain Yeeh Industrial Co., Ltd. (PHLE). They provide many kind of materials and types rubber oil seal for your choosing, and they also doing customize according to customer’s requirement.

 

 

Article Source: http://www.silentblocbush.com/rubber-oil-seals.html

Stretch Film vs. Shrink Film, What’s the Difference?

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It’s a common misconception that people believe stretch film and shrink film are the same thing. It’s true that both shrink and stretch films are designed to unitize products onto pallets and both are generally made from polyethylene resins. Shrink films are produced on blown film lines and stretch films can be produced on either blown or cast film lines. Outside of those similarities, the two packaging systems don’t have a lot of other common characteristics.

 

Shrink films contain a high percentage of low density polyethylene (LDPE), which is the same type of resin used to make bread bags and newspaper overwrap sleeves.  When fabricated under very specific parameters, LDPE gives shrink film its “shrink”.  The stress or tension required to make the film contract is frozen in during the fabrication process. To activate shrink film, a heat source is required such as a heat tunnel, heat gun, or torch. When sufficient heat is applied to the film, it approaches its melting point and the film begins to draw up or “shrink”. Because the film can only shrink so far, each product to be wrapped has to be matched with a specific size and configuration of film. As film resins go, LDPE does not have good puncture or tear resistance and has a relatively low load holding force. In order to provide sufficient load containment and protection for the load, these films are generally several times thicker than most stretch films.

 

In contrast, most stretch films contain high levels of linear low density polyethylene (LLDPE) and, depending on the end-use application, can stretch from 25 to 300%.  Stretch films are either designed to be applied by hand or by machine. Hand films usually have minimal stretch (25-100%) in order to aid the operator in applying the product and are in many ways similar to a large roll of very thin tape. Machine films on the other hand can have very high stretch levels (150 -300%) and, because they are applied by automated equipment, can be configured to exert very high levels of tension on a load if desired.

 

Shrink films are good for applications where the object to be protected requires five-sided protection (top and four sides) or is very large (boats and industrial equipment). For five-sided protection on finished products such as washer/dryers, refrigerators and other appliances, along with bagged resins and cement/concrete, stretch hooders have started replacing shrink films as the older shrink tunnels are decommissioned and new, more energy efficient equipment takes its place.

 

If you have any interest in shrink film machine, I recommend that you can visit the website of Jumbo Steel Machinery Co., Ltd.

 

For over 25 years, Jumbo Steel has dedicated itself to the research of production technology for PVC shrinkable film. The company has made great improvements in product prescription and machine performance, upgrading the quality and efficiency of PVC shrinkable films. Jumbo Steel PVC shrink film machine has been sold worldwide, and has earned a reputation for its superior machine and outstanding production know-how. Get more details please do not hesitate to send inquiry or contact with Jumbo Steel immediately.

 

 

Article Source: http://www.paragon-u.com/bid/252257/Stretch-Film-vs-Shrink-Film-What-s-the-Difference