Rule based DFM analysis for forging

Rule based DFM analysis for forging is the controlled deformation of metal into a specific shape by compressive forces. The forging process goes back to 8000 B.C. and evolved from the manual art of simple blacksmithing. Then as now, a series of compressive hammer blows performs the shaping or forging of the part. Modern forging uses machine driven impact hammers or presses that deforms the work-piece by controlled pressure.
The forging process is superior to casting in that the parts formed have denser microstructures, more defined grain patterns, and less porosity, making such parts much stronger than a casting. All metals and alloys are forgeable, but each will have a forgeability rating from high to low or poor. The factors involved are the material's composition, crystal structure and mechanical properties all considered within a temperature range. The wider the temperature range, the higher the forgeability rating. Most forging is done on heated work-pieces. Cold forging can occur at room temperatures. The most forgeable materials are aluminum, copper, and magnesium. Lower ratings are applied to the various steels, nickel, and titanium alloys. Hot forging temperatures range from 93°C (200°F) to 1650°C (3000°F) for refractory metals.
Types of forging.
Open die forging.
In open die forging a cylindrical billet is subjected to upsetting between a pair of flat dies or platens. Under frictionless homogeneous deformation, the height of the cylinder is reduced and its diameter is increased. Forging of shafts, disks, rings etc. are performed using the open die forging technique. Square cast ingots are converted into a round shape by this process. Open die forging is classified into three main types; cogging, fullering and edging.
Close die forging.
Also known as impression die forging, impressions are made in a pair of dies. These impressions are transferred to the work-piece during deformation. A small gap between the dies called flash gutter is provided so that the excess metal can flow into the gutter and form a flash. Flash plays an important role during the deformation of the work-piece inside the die cavity. Due to the high length to thickness ratio of the flash gutter, friction in the gap is very high. Because of this, the material in the flash gap is subjected to high pressure. There is high resistance to flow. This in turn promotes effective filling of the die cavity. In hot forging, the flash cools faster as a result of it being smaller in size. This enhances the resistance of the flash material to deformation resistance. As a result of this, the bulk of work-piece is forced to deform and fill the die cavity more effectively – even intricate parts of the die cavity is filled.
Hot forging.
Hot forging is defined as working a metal above its recrystallization temperature. The main advantage of hot forging is that as the metal is deformed the strain-hardening effects are negated by the recrystallization process.
Cold forging.
Cold forging is defined as working a metal below its recrystallization temperature, but usually around room temperature.
Categories of tolerances.
Group 1.
Length, width and height tolerances, mismatch tolerances, residual flash (and trimmed flat) tolerances, and pierced hole tolerances.
Group 2.
Thickness tolerances and ejector mark tolerances.
Group 3.
Straightness and flatness tolerances and tolerances for centre-to-centre dimensions.
Group 4.
Fillet and edge radii tolerances, Burr tolerances, surface tolerances, tolerances on draft angle surfaces, eccentricity tolerances for deep holes, eccentricity tolerances for pierced holes, tolerances on concentric bosses, tolerances for unforged stock, and tolerances for deformation of sheared ends.
Deviations of forms.
The tolerances for lengths, widths, heights, and thicknesses cover IL only the diligences of dimensions, but also the deviations of form which are: a) Out of round, b) Deviations from cylindricity c) Deviations from parallelism, and d) Other deviations from the specified contour. The deviations arc not to exceed the limits given by the tolerances. In extreme cases they may cover the whole fields of tolerances unless other is agreed to between the supplier and purchaser. Where restrictions deviations of form have been agreed upon, this shall be noted on the drawing.
Design procedure.
Information required by forger.
In order to assist the forging supplier to utilize his experience to the best effect, both in designing the dies and tools and in establishing forging inspection procedures, rt is in the purchaser's interest to supply the following
Information: a) A finished machined drawing; b) Details and dimensions of machining locations (prior notice should be given of any subsequent changes in these location points) c) Anv other relevant information on machining operations and function of the component.
Preparation.
It is recommended that the drop drawing which should then be submitted forger should prepare the forging to the purchaser for approval, and, if necessary, for joint consultation.
In instances where the purchaser wishes to prepare his own fully dimensioned forging drawing, it is no less necessary that the drawing of the finished machined component and the other information referred to above should be made available to the supplier.
Indication of dimensions on drawings.
It is imperative to note that, with the exception concerning draft angle surfaces the tolerances indicated in this standard shall be applied only to those dimensions specifically indicated on the agreed forging drawing.
For this reason, the method of indicating dimensions on the forging drawing has a vital bearing on the dimensional control of the forging.
Tolerances for dimensions not shown on the forging drawing may not be taken from the standard but may be determined, if required, only by calculation based on the dimensions and tolerances which are already shown on the agreed forging drawing.
Indication of tolerances on drawings.
All forging drawings should be endorsed, ‘Tolerances conform with IS: 3469 (Part II)-1974 unless otherwise indicated
For correct endorsement of forging drawings the following form of presentation of tolerances at the foot of the drawing is recommended:
Category: 1.Lengths and overall diameters 2. Widths 3. Heights 4. Mismatch 5. Residual flash and trimmed flat 6. Thickness 7. Straightness 8. Flatness 9. Fillet and edge radii 10. Surfaces
Any tolerances which are only applicable to specific dimensions shall be indicated on the drawing against the particular dimensions concerned. Ejector mark tolerances and burr tolerances should be shown on the forging drawing against the specific locations. Any special tolerances agreed between the purchaser and the supplier shall be indicated clearly on the forging drawing and shall, wherever possible be entered against the specific dimensions concerned.
Importance of drawings.
The drawing of the forged part which has been accepted by the purchaser is the valid document for inspection of the forged part. This drawing is also the only valid document for tolerances on parts of the forging remaining unmachined
Processes.
There are many different kinds of forging processes available, however they can be grouped into three main classes: 1. Drawn out: length increases, cross-section decreases 2. Upset: Length decreases, cross-section increases 3. Squeezed in closed compression dies: produces multidirectional flow. Common forging processes include: roll forging, swaging, cogging, open-die forging, impression-die forging, press forging, automatic hot forging and upsetting.
Open-die drop-hammer forging.
Open-die forging is also known as smith forging. In open-die forging a hammer comes down and deforms the workpieces, which is placed on a stationary anvil. Open-die forging gets its name from the fact that the dies (the working surfaces of the forge that contract the workpiece) do not enclose the workpiece, allowing it to flow except where contacted by the dies. Therefore, the operator needs to orient and position the workpiece to get the desired shape. The dies are usually flat in shape but may have a specially shaped surface for specialized operations; for instance the die may have a round, concave, or convex surface or be a tool to form holes or be a cut-off tool. Open-die forging lends itself to short runs and is appropriate for art smiting and custom work. Other times open-die forging is used to rough shape ingots to prepare it for further operations. This can also orient the grains to increase strength in the required direction.
Impression-die drop-hammer forging.
Impression-die forging is also called closed-die forging. In impression-die work metal is placed in a die resembling a mold, which is attached to the anvil. Usually the hammer die is shaped as well. The hammer is then dropped on the workpiece, causing the metal to flow and fill the die cavities. The hammer is generally in contact with the workpiece on the scale of milliseconds. Depending on the size and complexity of the part the hammer may be dropped multiple times in quick succession. Excess metal is squeezed out of the die cavities; this is called flash. The flash cools more rapidly than the rest of the material; this cool metal is stronger than the metal in the die so it helps prevent more flash from forming. This also forces the metal to completely fill the die cavity. After forging the flash is trimmed off.
In commercial impression-die forging the workpiece is usually moved through a series of cavities in a die to get from an ingot to the final form. The first impression is used to distribute the metal into the rough shape in accordance to the needs of later cavities; this impression is called edging, fullering, or bending impression. The following cavities are called blocking cavities in which the workpiece is working into a shape that more and more resembles the final product. These stages usually impart the workpiece will generous bends and large fillets. The final shape is forged in a final or finisher impression cavity. If there is only a short run of parts to be done it may be more economical for the die to lack a final impression cavity and rather machine the final features.
Impression-die forging has been further improved in recent years through increased automation which includes induction heating, mechanical feeding, positioning and manipulation, and the direct heat treatment of parts after forging.
One variation of impression-die forging is called flashless forging, or true closed-die forging. In this type of forging the die cavities are completely closed, which keeps the workpiece from forming flash. The major advantage to this process is that less metal is lost to flash. Flash can account for 20 to 45% of the starting material. The disadvantages of this process included: additional cost due to a more complex die design, the need for better lubrication, and better workpiece placement.
There are other variations of part formation that integrate impression-die forging. One method incorporates casting a forging preform from liquid metal. The casting this then removed after it is cooled to a solid state, but while still hot. It is then finished in a single cavity die. The flash is trimmed and then quenched to room temperature to harden the part.
Another variation follows the same process as outlined above, except the preform is produced by the spraying deposition of metal droplet into shaped collectors (similar to the osprey process).
Closed-die forging has a high initial cost due to the creation of dies and required design work to make working die cavities. However, it has low reoccurring costs for each part, thus forgings become more economical with more volume. This is one of the major reasons forgings are often used in the automotive and tool industry. Another reason forgings are common in these industrial sectors is because forgings generally have about a 20% higher strength to weight ratio compared to cast or machined parts of the same material.
Design of impression-die forgings and tooling.
Forging dies are usually made of high-alloy or tool steel. Dies must be impact resistant, wear resistant, maintain strength at high temperatures, and have the ability to withstand cycles of rapid heating and cooling. In order to produce a better, more economical die the following rules should be followed:
1. The dies should part along a single, flat plane if at all possible, If not the parting plan should follow the contour of the part. 2. The parting surface should be a plane through the center of the forging and not near an upper or lower edge. 3. Adequate draft should be provided; a good guideline is at least 3° for aluminum and 5° to 7° for steel 4. Generous fillets and radii should be used 5. Ribs should be low and wide 6. The various sections should be balanced to avoid extreme difference in metal flow 7. Full advantage should be taken of fiver flow lines 8. Dimensional tolerances should not be closer than necessary. The dimensional tolerances of a steel part produced using the impression-die forging method are outlined in the table below. The dimensions across the paring plane are affected by the closure of the dies, and are therefore dependent die wear and the thickness of the final flash. Dimensions that are completely contained within a single die segment or half can be maintained at a significantly greater level of accuracy. A lubricant is always used when forging to reduce friction and wear. It is also used to as a thermal barrier to restrict heat transfer from the workpiece to the die. Finally the lubricant acts as a parting compound to prevent the part from sticking in one of the dies.
Press forging.
Press forging is variation of drop-hammer forging. Unlike drop-hammer forging, press forges work slowly by applying continuous pressure or force. The amount of time the dies are in contact with the workpiece is measured in seconds (as compared to the milliseconds of drop-hammer forges). The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece.
Drop-hammer forging usually only deforms the surfaces of the workpiece in contact with the hammer and anvil; the interior of the workpiece will stay relatively undeformed. There are a few disadvantages to this process, most stemming from the workpiece being in contact with the dies for such an extended period of time. The workpiece will cool faster because the dies are in contact with workpiece; the dies facilitate drastically more heat transfer than the surrounding atmosphere. As the workpiece cools it becomes stronger and less ductile, which may induce cracking if deformation continues. Therefore, heated dies are usually used to reduce heat loss, promote surface flow, and enable the production of finer details and closer tolerances. The workpiece may also need to be reheated.
Press forging can be used to perform all types of forging, including open-die and impression-die forging. Impression-die press forging usually requires less draft than drop forging and has better dimensional accuracy. Also, press forgings can often be done in one closing of the dies, allowing for easy automation.
Upset forging.
Upset forging increases the diameter of the workpiece by compressing its length. Based on number of pieces produced this is the most widely used forging process. Upset forging is usually done in special high speed machines; the machines are usually set up to work in the horizontal plane to facilitate the quick exchange of workpieces from one station to the next. The initial workpiece is usually wire or rod, but some machines can accept bars up to 25 cm (10 in.) in diameter. The standard upsetting machine employs split dies that contain multiple cavities. The dies open enough to allow the workpiece to move from one cavity to the next; the dies then close and the heading tool, or ram, then moves longitudinally against the bar, upsetting it into the cavity. If all of the cavities are utilizes on every cycle then a finished part will be produced with every cycle, which is why this process is ideal for mass production.
A few examples of common parts produced using the upset forging process are engine valves, couplings, bolts, screws, and other fasteners.
The following three rules must be followed when designing parts to be upset forged:
Automatic hot forging.
The automatic hot forging process involves feeding mill-length steel bars (typically 7 m or 24 ft long) into one end of the machine at room temperature and hot forged products emerge from the other end. This all occurs very quickly; small parts can be made at a rate of 180 parts per minute (ppm) and larger can be made at a rate of 90 ppm. The parts can be solid or hollow, round or symmetrical, up to 6 kg (12 lbs), and up to 18 cm (7 in.) in diameter. The main advantages to this process are its high output rate and ability to accept low cost materials. Little labor is required to operate the machinery. There is no flash produced so material savings are between 20 - 30% over conventional forging. The final product is a consistent 1050 °C (1900 °F) so air cooling will result in a part that is still easily machinable (the advantage being the lack of annealing required after forging). Tolerances are usually ±0.3 mm (±0.012 in.), surfaces are clean, and draft angles are 0.5 to 1°. Tool life is nearly double that of conventional forging because contact times are on the order of 6/100 of a second.
The downside to the process is it only feasible on smaller symmetric parts and cost; the initial investment can be over $10 million, there large quantities are required to justify this process. The process starts by heating up the bar to 1200 to 1300 °C (2200 to 2350 °F) in less than 60 seconds using high power induction coils. It is then descaled with rollers, sheared into blanks, and transferred several successive forming stages, during which it is upset, preformed, final forged, and pierced (if necessary). This process can also be couple with high speed cold forming operations. Generally, the cold forming operation will do the finishing stage so that the advantages of cold-working can be taken advantage of, while maintaining the high speed of automatic hot forging.
Examples of parts made by this process are: wheel hub unit bearings, transmission gears, tapered roller bearing races, stainless steel coupling flanges, and neck rings for LP gas cylinders. Manual transmission gears are an example of automatic hot forging used in conjunction with cold working.
Roll forging.
Roll forging is a process where round or flat bar stock is reduced in thickness and increased in length. Roll forging is performed using two cylindrical or semi-cylindrical rolls, each containing or more shaped grooves. A bar is inserted into the rolls and when it hits a stop the rolls rotate and the bar is progressively shaped as it is rolled out of the machine.
The workpiece is then transferred to the next set of grooves or turned around and reinserted into the same grooves. This continues until the desired shape and size is achieved. The advantages of this process is there is no flash and it imparts a favorable grain structure into the workpiece. Examples of products produced using this method include axles, tapered levers and leaf springs.
Net-shape and near-net-shape forging.
This process is also known as precision forging. This process was developed to minimize cost and waste associated with post forging operations. Therefore, the final product from a precision forging needs little to no final machining. Cost savings are gained from the use of less material, and thus less scrap, the overall decrease in energy used, and the reduction or elimination of machining. Precision forging also requires less or a draft, 1° to 0°. The downsize of this process is its cost, therefore it is only implemented if significant cost reduction can be achieved.
Equipment.
The most common thought of forging equipment is the hammer and anvil. The principles behind the hammer and anvil are still used today in drop-hammer equipment. The principle behind the machine is very simple, raise the hammer and then drop it or propel it into the workpiece, which rests on the anvil. The main variations between drop-hammers is in the way that the hammer is powered; the most common being air and steam hammers. Drop-hammers usually operate in the vertical position. The main reason for this is because excess energy (energy that isn't used to deform the workpiece) that isn't released as heat or sound needs to be transmitted to the foundation. Moreover, a large machine base is needed to absorb the impacts.
To overcome some of the shortcomings of the drop-hammer the counterblow machine or impactor is used. In a counterblow machine both the hammer and anvil move and the workpiece is held between them. Here excess energy becomes recoil. This allows for the machine to work horizontally and consist of a smaller base. Other advantages include less noise, heat and vibrations. It also produces a distinctly different flow pattern. Both of these machines can be used for open die or closed die forging. A forging press, often just called a press, is used for press forging.
There are two main types: mechanical and hydraulic presses. Mechanical presses function by using cams, cranks or toggles to produce a preset (a predetermined force at a certain location in the stroke) and reproducible stroke. Due to the nature of this type of system difference forces are available at different stroke positions. Mechanical presses are faster than their hydraulic counterparts (up to 50 strokes per minute). Their capacities range from 3 to 160 MN (300 to 18,000 tons). Hydraulic presses use fluid pressure and a piston to generate force. The advantages of a hydraulic press over a mechanical press is its flexibility and greater capacity. The disadvantages are that they are slower, larger and more costly to operate. The roll forging, upsetting, and automatic hot forging processes all use specialized machinery.


Rule-based DFM analysis for direct metal laser sintering

Rule based DFM analysis for direct metal laser sintering. Direct metal laser sintering (DMLS) is one type of additive manufacturing process that allows layer by layer printing of metal parts having complex geometries directly from 3D CAD data. It uses a high-energy laser to sinter powdered metal under computer control, binding the material together to create a solid structure. DMLS is a net shape process and allows the creation of highly complex and customized parts with no extra cost incurred for its complexity.
DMLS is being used to fabricate complex metal parts that are difficult to do so using traditional manufacturing processes thus gives immense freedom to the designer while designing the component. However, there are certain Design for Manufacturability (DFM) considerations that should be taken care of while designing the parts to be printed. DFM provides guidance to the design team in making the product structure more compliant to the given manufacturing process. It removes the wall between the designing and manufacturing phases of product development thus enables designers to take advantages of all the inherent costs and other benefits available in the manufacturing process. The early considerations of DFM principles and guidelines can lead to significant cost and time cutting in the final development of the product. Some of the common guidelines for DMLS are:
Size.
The size of the part that can be printed depends upon the printer that is being used. With the current technology a maximum build size of 228 X 228 X 304 mm can be achieved. Hence, the size of the part to be printed should be within required dimensions. DMLS has a minimum sintering width (depends on laser diameter) varying from 0.6 mm to 0.9 mm. This defines the minimum external feature size of the part and thus the design with any external features having smaller dimensions must be avoided.
Accuracy.
The accuracy and surface roughness of the part depends on the powder grain size ranging between 50 μm to 100 μm. The layer thickness which lies between 0.02 mm and 0.05 mm determines the resolution in the vertical direction. Therefore, the regions of the parts which require high accuracy should be designed with planned allowance of 0.1 mm to 0.5 mm and secondary finishing and/or machining operations should then be used to achieve the required accuracy.
Overhangs.
In DMLS, powder bed supports the parts and keep them held in place. However, support structures are explicitly required for most of the downward facing surfaces that make an angle less than 45 degrees with the powder bed. This is because powder bed alone is not sufficient enough to hold the liquid phase of the metal that is created when laser is scanning the powder. Support structures are also required to restrict curling/warping of the melted powder due to high-temperature gradients. The overhangs having angles less than 45 degrees should be avoided if possible at the design stage. The main advantage of this is to reduce material usage and the post processing requirement of removing support structures from the designed components.
Height.
The total number of layers required to build the whole part is directly proportional to the height of the part measured along the build direction. Every layer of the part to be printed requires tightly laying compacted thin layer of powdered material using roller, tracing of laser according to the 3D data fed to the machine in the horizontal plane and incremental lowering of powder bed for the successive layer to be laid. These processes require a significant amount of time thus redesigning the product for smaller heights may save manufacturing time greatly. The build orientation should be such that the height of the part should be least along the build direction.
Anisotropy.
The main direction of heat flow which is generated by the laser at the top is along the build direction due to the fact that powder bed lying at the bottom is the major heat sink. The layered addition of material and the directional heat flow in DMLS lead to the growing of microstructural grains along the build direction leading to anisotropic properties. The structure printed through DMLS has weaker properties along the build direction. This anisotropy can be removed using heat treatment methods but they are highly energy intensive and costly processes. Hence, it is advisable to consider the anisotropy in the very beginning of designing such structural parts and the direction of largest stress in the structure should lie in the horizontal plane.
Complexity.
Being an additive manufacturing technique, DMLS doesn't incur any extra cost for the complexity of the part. The build volume along with the number of layers is what determines the production cost and time. DMLS eliminates the need for tool production however such technologies are impervious to economies of scale. Therefore, it is recommended to design parts with least amount of superfluous volumes, building only the relevant geometries. Furthermore, the parts should be designed to avoid assembly requirements because printing sub-assembly with intricate geometries is now possible.


Peening

In metallurgy, peening is the process of working a metal's surface to improve its material properties, usually by mechanical means, such as hammer blows, by blasting with shot (shot peening), focusing light (laser peening), or in recent years, with water column impacts (water jet peening) and cavitation jets (cavitation peening). With the notable exception of laser peening, peening is normally a cold work process tending to expand the surface of the cold metal, thus inducing compressive stresses or relieving tensile stresses already present. It can also encourage strain hardening of the surface metal.
Residual stress.
Plastic deformation from peening induces a residual compressive stress in a peened surface, along with tensile stress in the interior. This stress state resembles the one seen in toughened glass, and is useful for similar reasons.
Surface compressive stresses confer resistance to metal fatigue and to some forms of corrosion, since cracks will not grow in a compressive environment. The benefit comes at the expense of higher tensile stresses deeper in the part. However, the fatigue properties of the part will be improved, since the stresses are normally significantly higher at the surface in part due to surface imperfections and damage.
Work hardening.
Cold working also serves to harden the material's surface. This makes cracks less likely to form at the surface and provides resistance to abrasion. When a metal undergoes strain hardening its yield strength increases but its ductility decreases. Strain hardening actually increases the number of dislocations in the crystal lattice of the material. When a material has a great number of dislocations, plastic deformation is hindered, and the material will continue to behave in an elastic way well beyond the elastic yield stress of the non-strain hardened material.
Residual strain / stretching.
Plastic deformation from peening can be useful in stretching the surface of an object.
One common use of this peening (stretching) process can be seen in the auto repair and auto custom fabrication industries where manual or machine assisted peening is used to stretch thin sheet metal to create curved surfaces. The manual method uses a hand held peening hammer and is a form of planishing. There are also machine assisted methods that use a version of a power hammer to peen the sheet metal.
Another use of the peening process is to flatten sheet metal and is specifically used as a primary technique to flatten steel belts used in industrial conveying and pressing operations. In this process a steel belt that has a cross curvature can be flattened by peening the concave surface to stretch it and thereby removing the cross-curvature by equalizing the surface length across the belt between the previously concave and convex surfaces. The shot peening of steel belts is usually achieved by using specialized equipment and special peening shot.
When peening is used to induce residual stress or work-harden an object, care needs to be taken with thin parts not to stretch the work-piece. Where stretching is unavoidable then allowances may need to be made in the part design or process application.
Use with welding.
Hand peening may also be performed after welding to help relieve the tensile stresses that develop on cooling in the welded metal (as well as the surrounding base metal). The level of reduction in tensile stress is minimal and only occurs on or near to the weld surface. Other methods, like heat spots (if applicable), help reduce residual tensile stresses. Peening will induce a higher hardness into the weld and this is something that should be avoided. For this reason, peening is not normally accepted by the majority of codes, standards or specifications. Any peening that is carried out on a weld should have been carried out on the weld procedure qualification test piece.
The welding procedure qualification test piece replicates all of the essential variables that will be used in production welding. If the weld is peened during the qualification of a welding procedure, the subsequent mechanical testing of the procedure qualification test piece will demonstrate the mechanical properties of the weld. These mechanical properties must, as a minimum, match the mechanical properties of the materials that have been welded together. If they do not, the procedure has failed and the welding procedure is not acceptable for use in production welding.
Sharpening blades.
Scythe and sickle blades have traditionally been sharpened by occasional peening followed by frequent honing in the field during use. A blade can be sharpened by reforming the malleable steel to create an edge profile that can then be honed. Nicks and cuts to the blade edge can be worked out of the blade by peening and a new edge profile then formed for honing.
Blades can be free-peened using various designs of peening anvils, or worked on a peening jig. A peening jig may have interchangeable caps that set different angles: a coarse angle can be set first about back from the edge, and a fine angle is then set on the edge, leaving an edge that lends itself to being easily honed. The blade can then be honed using progressively finer honing stones until it is ready for use.
History.
During construction of Barker Dam hydroelectric facilities in Colorado between 1908 and 1910, workers discovered that striking welds while they were still warm improved their strength.
The first published article about peening was written in Germany in 1929, and was specifically about shot peening. The first patent for shot peening was taken out in Germany in 1934 but was never commercially implemented. Independently in 1930, a few engineers at Buick noticed that "shot blasting" (as it was originally termed) made springs resistant to fatigue. This process was then adopted by the automotive industry. Zimmerli first published a report in 1940. John Almen did more research, and during World War 2 introduced it to the aircraft industry.
By 1950, peening became an accepted process and was being included in engineering literature. In the same year, peen forming was invented to form the wing skin of the Super Constellation aircraft.
In the early 1970s, peening experienced a major innovation when researchers such as Allan Clauer at Battelle labs in Columbus, Ohio applied high-intensity laser beams onto metal components to achieve deep compressive residual stresses, which they patented as Laser Shock Peening, and became known as laser peening in the late 1990s, when it was first applied to gas-fired turbine engine fan blades for the U.S. Air Force.


Belt problem

The belt problem is a mathematics problem which requires finding the length of a crossed belt that connects two circular pulleys with radius "r"1 and "r"2 whose centers are separated by a distance "P". The solution of the belt problem requires trigonometry and the concepts of the bitangent line, the vertical angle, and congruent angles.
Solution.
Clearly triangles ACO and ADO are congruent right angled triangles, as are triangles BEO and BFO. In addition, triangles ACO and BEO are similar. Therefore angles CAO, DAO, EBO and FBO are all equal. Denoting this angle by formula_1 (denominated in radians), the length of the belt is
This exploits the convenience of denominating angles in radians that the length of an arc = the radius × the measure of the angle facing the arc.
To find formula_1 we see from the similarity of triangles ACO and BEO that
For fixed "P" the length of the belt depends only on the sum of the radius values "r"1 + "r"2, and not on their individual values.
Pulley problem.
There are other types of problems similar to the belt problem. The pulley problem, as shown, is similar to the belt problem; however, the belt does not cross itself. In the pulley problem the length of the belt is
where "r"1 represents the radius of the larger pulley, "r"2 represents the radius of the smaller one, and:
Applications.
The belt problem is used in the design of aeroplanes, bicycle gearing, cars, and other items with pulleys or belts that cross each other. The pulley problem is also used in the design of conveyor belts found in airport luggage belts and automated factory lines.


Manufacturing Technologies Association

The Manufacturing Technologies Association (MTA) is a UK trade association representing the manufacturing technologies industry. The MTA sits at the core of the engineering based manufacturing sector and as an association works tirelessly to ensure member companies are as commercially successful as possible.
The association's key activities include:
- Representing engineering based manufacturing and supporting the advanced engineering sector through lobbying, media contact and networking.
- Providing relevant and specific industry intelligence
- Encouraging talent through funding and support for workplace training and education initiatives in schools, colleges and universities.
- Delivering the UK's only major exhibition focused on manufacturing technologies – MACH (owned and organised by the MTA)
Membership of the MTA is open to companies involved with the manufacturing technologies sector and end users of such technology.
Function.
The MTA represents UK companies, their associates and affiliates who drive UK manufacturing technology, innovation and quality.
The website contains a member & product directory by geographic position. It also provides information and statistics on the economic health of the British manufacturing markets.
MTA is the owner and organiser of the UK's premier manufacturing event - the MACH exhibition, a week-long event held biennially in April at the NEC.
The types of manufacturing technologies covered by the organisation, and the exhibition, include:
History.
The original Machine Tools Trades Association (MTTA) was formed in 1919, becoming the Machine Tools Technologies Association. Since its formation the association has evolved into a trade body with a global support network, promoting internationally competitive trade in manufacturing technologies.
Structure.
The MTA is based in London, with close contact with the British Government through the Department of Business Innovation and Skills (BIS) (United Kingdom), CBI and UK Trade & Investment.
The association's offices are located on "Bayswater Road" (A402) next to Lancaster Gate tube station.
The association also provides a secretariat service to the Federation of British Hand Tool Manufacturers (FBHTM), and the MTA Tooling Group, formerly the British Hard Metal and Engineers' Cutting Tools Association (BHECTA).


Fay automatic lathe

The Fay automatic lathe was an automatic lathe tailored to cutting workpieces that were mounted on centers (tools with pointed ends to accurately position a center-drilled workpiece about an axis, either directly or by using a mandrel). It could also do chucking work (feeding of unformed blanks or pieces of stock from a magazine to be automatically gripped by the machine for turning). Examples of workpieces included automotive steering knuckles and transmission gears, and such work done on mandrels as flanges, disks, and hubs. The machine tool was developed by F.C. Fay of Philadelphia and improved by Otto A. Schaum. It was originally manufactured by the Fay & Scott Machine Shop. James Hartness acquired manufacturing rights on behalf of the Jones & Lamson Machine Company and manufactured an improved version, developed under the management of Ralph Flanders.
In 1937 Roe, writing for the American Society of Mechanical Engineers, framed the importance of the Fay automatic lathe to the capabilities of machine tools by saying that, "This machine does for the engine lathe what Spencer did for the old hand-operated turret lathe." These machines took an entire class of turned work formerly requiring an operator to execute the series of movements necessary to shape a piece of metal (manual control) and allowed the same work to be done automatically. This step forward in automation lowered a manufacturer's unit expense per part by reducing labor costs. Today, numerically controlled (CNC) machine tools such as turning centers, turn-mills, and rotary transfer machines have largely supplanted cam-operated automatics.


Cloud manufacturing

Cloud manufacturing (CMfg) is a new manufacturing paradigm developed from existing advanced manufacturing models (e.g., ASP, AM, NM, MGrid) and enterprise information technologies under the support of cloud computing, Internet of Things (IoT), virtualization and service-oriented technologies, and advanced computing technologies. It transforms manufacturing resources and manufacturing capabilities into manufacturing services, which can be managed and operated in an intelligent and unified way to enable the full sharing and circulating of manufacturing resources and manufacturing capabilities. CMfg can provide safe and reliable, high quality, cheap and on-demand manufacturing services for the whole lifecycle of manufacturing. The concept of manufacturing here refers to big manufacturing that includes the whole lifecycle of a product (e.g. design, simulation, production, test, maintenance).
The concept of Cloud manufacturing was initially proposed by the research group led by Prof. Bo Hu Li and Prof. Lin Zhang in China in 2009.
 Related discussions and research were conducted hereafter, and some similar definitions (e.g. Cloud-Based Design and Manufacturing (CBDM).
) to cloud manufacturing were introduced.
Cloud manufacturing is a type of parallel, networked, and distributed system consisting of an integrated and inter-connected virtualized service pool (manufacturing cloud) of manufacturing resources and capabilities as well as capabilities of intelligent management and on-demand use of services to provide solutions for all kinds of users involved in the whole lifecycle of manufacturing.
Types.
Cloud Manufacturing can be divided into two categories.
In CMfg system, various manufacturing resources and abilities can be intelligently sensed and connected into wider Internet, and automatically managed and controlled using IoT technologies (e.g., RFID, wired and wireless sensor network, embedded system). Then the manufacturing resources and abilities are virtualized and encapsulated into different manufacturing cloud services (MCSs), that can be accessed, invoked, and deployed based on knowledge by using virtualization technologies, service-oriented technologies, and cloud computing technologies. The MCSs are classified and aggregated according to specific rules and algorithms, and different kinds of manufacturing clouds are constructed. Different users can search and invoke the qualified MCSs from related manufacturing cloud according to their needs, and assemble them to be a virtual manufacturing environment or solution to complete their manufacturing task involved in the whole life cycle of manufacturing processes under the support of cloud computing, service-oriented technologies, and advanced computing technologies.
Four types of cloud deployment modes (public, private, community and hybrid clouds) are ubiquitous as a single point of access.
Resources.
From the resource’s perspective, each kind of manufacturing capability requires support from the related manufacturing resource. For each type of manufacturing capability, its related manufacturing resource comes in two forms, soft resources and hard resources.


Ifco tray

IFCO trays (also known as RPCs (the abbreviation for reusable packaging containers), or reusable containers, or reusable crates) are a type of reusable packaging for transporting fresh food produce. IFCO SYSTEMS is the name of the company that first developed a pooling service for reusable plastic trays for fresh produce in 1992, when the company was founded in Pullach, Germany. IFCO is the acronym for International Food Container Organization.
They are attractive for environmental reasons due to their ease of reuse, their capability of being stacked when full of produce in many different configurations and that they can be flattened when empty for compact return to producers/shippers/growers or for storage purposes.
Reusable packaging.
The IFCO RPCs and trays are used for transporting perishable products and are available in different designs customized to the requirements of the produce. There are IFCO trays for fresh food, fruit and vegetables, bananas, baked goods, eggs, dairy, convenience foods, meat and fish.
Zero Waste.
When the IFCO trays reach the end of their service life and can no longer be repaired, they are granulated and made into new IFCO RPCs. The raw material stream for the IFCO reusable crates is fully traceable. The company uses 100% of the available material from the broken or end-of-use crates. The IFCO trays generally have a life span of more than 10 years, before they are made into new crates. There is no packaging waste and there is a 100% material reutilization.
Pooling.
IFCO trays are only available through the IFCO pooling service. Customers of the service share the reusable containers in a continuous closed loop. IFCO SYSTEMS refer to this pooling loop as the IFCO SmartCycle.
IFCO supplies the reusable containers to farmers and producers of fresh produce and perishable items. Customers that use the SmartCycle are supplied with clean, sanitized IFCO RPCs at harvest or at the end of the production cycle. The produce is shipped or transported in the reusable plastic containers on pallets to the retailers, where the produce generally goes on display at the Point of Sale in the IFCO trays. This reduces the number of touchpoints with the produce and aims to reduce the potential for produce damage and waste, extending the shelf life of the fresh food produce in the process.
When empty and used, the reusable containers are recovered and returned to the IFCO wash centers, where they are checked, repaired (if necessary), washed, and then supplied to customers and used again.
Circular economy model.
The IFCO pooling service of RPCs and material reutilization is based on the circular economy model, which promotes the reuse, sharing, repair, refurbishment, remanufacturing and recycling within a closed-loop system in order to avoid waste and reduce the environmental impact of industrial designs.
Sustainability.
Compared to disposable products and packaging, reusable containers help reduce the overall environmental impact of the fresh grocery supply chain.
As the IFCO trays can be folded compactly, they require less space in the reverse logistics as they are mainly the same size and are therefore compatible when folded. More IFCO RPCs can be stacked in trucks and in storage, saving food miles, energy consumption and storage costs.
Cradle to Cradle Design.
The IFCO European line of Lift Lock reusable plastic containers (RPCs) are the first and only reusable food packaging containers to be awarded Cradle to Cradle Certified® (Version 3.1) at the Silver level by the independent non-profit Cradle to Cradle Products Innovation Institute, which is based on the Cradle to Cradle design philosophy of Michael Braungart and William McDonough. These IFCO trays were awarded Gold for Material Reutilization.
Food safety.
The IFCO RPCs are washed and sanitized to food-grade quality after each use. The washing process is independently audited.
Company history.
Founded in 1992 in Germany, the company originally focused on Europe and expanded into the US market in 2003, when it launched the first Black RPC.
IFCO serves customers in over 50 countries, has offices in over 30 countries, 89 service centers and employs around 1,100 people. The company has a pool of over 314 million reusable plastic containers, which are used in over 1.7 billion shipments of fresh produce every year. Over 14,000 producers use the IFCO trays, and over 300 retailers.
IFCO is an independent company since its acquisition by Triton and Abu Dhabi Investment Authority (ADIA) in May 2019 from the Brambles company who had owned IFCO since 2011.
Innovation.
IFCO Systems has filed a total of 1,174 patents for the IFCO reusable plastic containers and pooling system.
Slogan.
The company slogan is: “A better supply chain serves us all. Let’s eat.”
Controversy.
Their adoption has generated controversy between developed countries which are consumers of produce and developing countries which are producers, primarily due to the cost of using the trays as opposed to using locally produced containers. In particular, many developing countries lack the capital-intensive infrastructure to develop and support the hi-technology plastic molding machinery necessary to produce the returnable trays. Analysis continues to compare the relative benefits of reusable trays, which require a full cycle (use, cleaning and return) versus one-time-use disposable containers which do not require return to the shipper, but instead are disposed of after one use. Disposable containers create a waste-disposal burden on recipients, while the returnable containers burden producers who must purchase containers and arrange for a return cycle.


US error coins

US error coins are error coins produced by the US government. There are three categories of error coins as provided by the American Numismatic Association. Metal usage and striking errors referred to widely as planchet errors, die errors, and mint striking errors. This does not include the varieties that the US Mint has issued over the years.
Since the inception of coin collecting there has been much controversy over what constitutes a true mint error. An organization of coin collectors named the Combined Organizations of Numismatic Error Collectors of America (CONECA) was created that specifically deals with mint errors.
Planchet errors.
A planchet is produced by punching blanks in sheet metal stock specially made for the types of mint blanks required. After the blanks are punched they are rolled on the edge placing an upset needed for the minting process. The blanks are then washed and annealed making them ready for the minting process
There are several types of planchet errors that include: improper alloy, wrong stock, imperfect blank, and lamination.
A planchet error may be caused by an improper alloy mixture. Improper alloy mixtures occur when the sheet stock contains uneven layers of the metals intended for the type of coin that is produced. A result of improper layers of metals is a coin produced without an intended surface layer of nickel. A dime or quarter without the nickel layer will contain only the copper alloy mixture.
A planchet error can be caused by using a blank intended for a different denomination or wrong stock. The result of using a blank intended for another denomination is the minting of the intended obverse and reverse on the wrong stock.
A planchet error also refers to many types of issues where an imperfect blank has been used. Pieces of the blank might be missing causing a half moon to be missing from the coin. Collectors denote missing parts of the planchet as "clipped planchets." A dirty or oily blank may cause the details of the coin to become dull or even missing. A piece of debris may find its way into the dies causing a series of lines to be minted on the surface of the coin.
A planchet may be in a state that causes peeling on the surface of the coin. The peeling of any part of the surface of a coin is known as a lamination error.
Below is a lamination error on a Jefferson nickel.
Die errors.
Die errors are caused by the mint dies wearing down over time or dies that have not been prepared identical to others that have been replaced. The result of preparing a set of new dies improperly from the original hub results in coin errors such as doubling, extra details, or missing details on the surface of the coin.
A die break is caused when the mint die suffers a crack and this crack feature is transposed onto the coins in the minting process. Coins minted with a die break have a thin line or lines that are raised running across the surface of the coin. Below is a photograph of a 1954-S Jefferson nickel with a die crack along the top of the portrait of Jefferson.
A die break can create coins that have deep impressions in a coin that is filled in with metal. The coin shows a raised patch of metal were the break occurred. This type of error is commonly known as a "cud" error.
Gouges in coins caused by flaws in dies, and die polishing mistakes resulting in coins minted with surface indentations, or polishing lines.
Dies that are damaged and used in the minting process also create errors resulting in coins having die chips embedded in the surface of the coin.
A die clash occurs when a planchet is not fed into the collar that holds the coin in place for the minting process. The two dies meet and each carries away part of the design embedded on the die. Coins minted using these dies cause coins to be minted with parts of the reverse design on the obverse or parts of the obverse on the reverse of the coin.
Die rotations cause coins to be minted with the reverse or obverse of the coin partially or fully rotated. A die rotation occurs when the dies become loose and they then turn.
When a mint worker polishes a die to remove a die clash or some other defect there may be instances where a part of the design is removed. The 3-legged Buffalo nickel was the direct result of die polishing and the removal of a leg. The 1970 Lincoln cent with the raised 7 is also the result of die polishing.
Before 1990, all US coin dies were subject to mint mark errors resulting from the preparation of the dies. The mint mark was hammered into the die manually sometimes causing a die to have a doubling. In the minting process this would create a series of coins with a distinct of slight doubling of the mint mark. Millions of these errors can be located on the internet for sale and are referred to as RPM’s
Doubled dies.
Doubled die coins are mainly created by a defective hub which is used to create many dies for the minting process. Collectors classify doubled dies as DDO (doubled die obverse coins), DDR (doubled die reverse) and OMM (over mint mark).
The over mint mark is created when a one date and mint mark is punched over another date, part of a date, or mint mark. These coins are generally restricted to the early minting process of coins dating before the turn of the century.
The DDO and DDR errors are related to any part of the coin that shows a distinct doubling. Pictured below is a 1969-S doubled die Lincoln cent.
Mint striking errors.
Collectors and organizations dedicated to collecting coins regard mint striking errors as those that have been created by the minting process. Mint striking errors are caused by the collar moving, cracking, or not being present in the minting process. The collar is a third die that actually holds the coin in place in the minting process. It is the collar that imprints the lettering on a coin, such as the lettering on the Presidential dollars.
Striking a coin with debris causes an indentation on the coin or the actual debris stamped into the coin.
In order to mint any US coin a retaining collar is used to keep the coin in place while it is pressed between the dies. If the retaining collar breaks or is missing, the coin is struck so that the metal of the planchet is actually expanded outward producing a larger version of the coin with most of the details present. This error is known as a broad struck error.
A coin that has been struck out of the collar and has double details such as two partial portraits, one normal and one that is overlapping and extending outside the normal circumference of the coin is denoted as a double striking error.
A brockage results when a coin is stuck in the collar and another planchet enters the collar and is pressed against the coin already minted. The details of the coins produced have the appearance of mirror images of the obverse and reverse.
A die cap is a coin that has been stamped a number of times and has the appearance of a soda cap. Metal flows around the side of the coin and the portrait appears deep in the coin.
Variations.
Variations are not mint errors in the technical sense. Variations in coins are caused by creating hubs and dies that are not exactly the same resulting in dates that can be compared as large to small, wide to thin etc. These die variations resulted in the 1960 large- and small-dated Lincoln cent, and the 1982 large- and small-dated series both in copper and copper-zinc cents minted.
Below are photographs of two Brilliant Uncirculated Jefferson nickels. Note that these are variations of dies used to mint the 1970-D Jefferson nickels. The die variation is clearly evident with the placement of the D in two different locations, one closest to the 1970 and the other closest to the rim of the coin.
There are some variations created by the mint site using different die sets. The best case of the mint using different die sets is the variation of the letters AM on the Lincoln cent. The AM letters are either touching or are distinctly apart in some Lincoln cents minted in 1998, 1999, 2000, and perhaps others to be discovered. Normally, the wide AM design is reserved for the Lincoln proof designs. Below is a photograph of a wide AM Lincoln cent.
Unclassified error coins.
Unclassified error coins are those that are difficult to categorize. Below are two unclassified error, one with the date flattened in a 1998 Jefferson nickel and another Jefferson nickel with a recessed S.
Counter stamped coins.
Counter stamped coins have a long history in the early days of minted coins. Many companies used counter stamping as a method to advertise their company. There are thousands of counter stamped coins some of which carry little value while others command values in the thousands. In any case, these coins were changed after leaving the mint, and are not true error coins.
Initials were sometime cut into coins. Some of these coins have been classified as "love tokens" having the initials of the person who counter stamped the coin. Below is a counter stamped Lincoln cent with a number 2 in a bar shape outline. This coin was found with some others with personal initials in a 5,000 piece coin bag purchased from a coin show.


Crash incompatibility

Crash incompatibility, crash compatibility, vehicle incompatibility, and vehicle compatibility are terms in the automobile crash testing industry. They refer to the tendency of some vehicles to inflict more damage on another vehicle (the "crash partner vehicle") in two-car crashes. Vehicle "incompatibility" is said to lead to more dangerous, fatal crashes, while "compatibility" can prevent injury in otherwise comparable crashes.
The most obvious source of crash incompatibility is mass; a high-mass vehicle such as a large MPV or SUV will tend to cause much more serious damage in a crash with a lighter vehicle such as a typical sedan or compact car. In particular, research by Michael Anderson and Maximilian Auffhammer suggests that "controlling for own-vehicle weight,
being hit by a vehicle that is 1,000 pounds heavier generates a 40-50% increase in fatality
risk." Incompatibility may also result from the specific shape, stiffness, or other design aspects of the impacting vehicles. For example, some SUVs and pickup trucks ride higher than cars and lack crumple zones to absorb impact energy. Another source of incompatibility is that heavier vehicles are required to have stronger front ends because of today's test requirements like the NCAP test.
The National Highway Traffic Safety Administration has done studies of the "aggressiveness" of vehicle designs. The term "aggressiveness" is used to denote the average injury risk a vehicle imposes on occupants of other vehicles during collisions. A 2003 NHTSA study estimated that in vehicle to vehicle crashes, the design of minivans was 1.16 times as aggressive as cars, pickups were 1.39 times more aggressive, and SUVs were 1.71 times more aggressive than cars. When weight was included in the analysis, light trucks (including SUVs) were estimated to be 3.3 times more aggressive than cars in head-on crashes and perhaps more so in side impact crashes.
These studies have been controversial as they affect public perception and policy decisions on CAFE standards and light truck safety test standards as they exist today. NHTSA does not define a car or a light truck based on weight (e.g., the Chrysler PT Cruiser is classified as a light truck whereas a Lexus LS 600h L, a vehicle that weighs 66% more per published specifications, is classified as a car). So while there have been no proposals to eliminate light trucks (which includes minivans, SUVs and pickups), doing so would not eliminate incompatibility because there would still be lighter vehicles crashing into heavier vehicles.
There has been extensive research and testing done by NHTSA, other governments, research organizations as well as automobile manufacturers to find solutions that improve safety in the small cars when colliding with larger vehicles. In the United States, a group of experts proposed major steps to improve compatibility and these have been accepted as a voluntary regulation by American automotive manufacturers as well as by most other companies selling vehicles in the U.S. The Canadian government has also accepted these recommendations. The recommendations require all manufacturers to either (a) lower the height of the primary structure (also called frame rail) of all SUV and pickup trucks so that they overlap the primary structure of the cars; or (b) add another structure (called Secondary Energy Absorbing Structure) to the SUVs and pickup truck that cannot meet the first option. Latest studies have shown that these have improved the safety in cars when struck by SUVs. However, no such benefit has been observed in pickup truck to car crashes. It is unclear whether or not certain aftermarket modifications are taken into account, such as "lift kits" which raise the frame or suspension of a vehicle for increased ground clearance. Such modifications would likely greatly reduce the effectiveness of modern auto-safety advances due to causing the rigid parts of a pickup or SUV to strike the weaker parts of lower vehicles, rather than the reinforced regions in an accident. State laws regarding the use of such modifications vary widely, and many have laws that aren't enforced. As of now, there are no Federal laws regarding the bumper height of trucks and SUV's.
Although much of the crash incompatibility debate in recent years has centered on SUVs, the concept has been around far longer. When subcompact cars were introduced in the 1970s, there was a fear that incompatibilities of mass and design could lead to more serious injuries for drivers of these smaller, lighter vehicles. Crash incompatibility remains an area of active study.


ALLDATA

ALLDATA LLC is an online source for automotive original equipment manufacturer (OEM) information. ALLDATA provides vehicle manufacturers' diagnostic and repair information.
ALLDATA was founded in 1986 to meet market demand for OE repair information. As computer technology took hold, ALLDATA began compiling the largest single source of OEM information available and converted it into a digital format. ALLDATA is known for online OEM information, used by over 300,000 professional technicians worldwide. The company expanded its product line to include collision information, business tools and support services for the global automotive industry.
In 1996, ALLDATA was purchased by AutoZone.


Željeznički prevoz Crne Gore

Željeznički prevoz Crne Gore (ŽPCG) (Cyrillic: Жељезнички превоз Црне Горе; English: Railway transport of Montenegro) is a joint-stock company that handles passenger transport within Montenegro, as well as operation of the Montenegrin rolling stock.
Rolling stock.
Rolling stock of Railway transport of Montenegro consists of 39 locomotives and 5 EMUs:
Passenger cars.
Railway transport of Montenegro also has following inventory of passenger cars:
Freight cars.
Freight cars in inventory are as follows:


Heat deflection temperature

The heat deflection temperature or heat distortion temperature (HDT, HDTUL, or DTUL) is the temperature at which a polymer or plastic sample deforms under a specified load. This property of a given plastic material is applied in many aspects of product design, engineering and manufacture of products using thermoplastic components.
Determination.
The heat distortion temperature is determined by the following test procedure outlined in ASTM D648. The test specimen is loaded in three-point bending in the edgewise direction. The outer fiber stress used for testing is either 0.455 MPa or 1.82 MPa, and the temperature is increased at 2 °C/min until the specimen deflects 0.25 mm. This is similar to the test procedure defined in the ISO 75 standard.
Limitations that are associated with the determination of the HDT is that the sample is not thermally isotropic and, in thick samples in particular, will contain a temperature gradient. The HDT of a particular material can also be very sensitive to stress experienced by the component which is dependent on the component’s dimensions. The selected deflection of 0.25 mm (which is 0.2% additional strain) is selected arbitrarily and has no particular physical significance.
Application in injection molding.
An injection molded plastic part is considered "safe" to remove from its mold once it is near or below the HDT. This means that part deformation will be held within acceptable limits after removal. The molding of plastics by necessity occurs at high temperatures (routinely 200 °C or higher) due to the low viscosity of plastics in fluid form (this issue can be addressed to some extent by the addition of plasticizers to the melt, which is a secondary function of a plasticizer). Once plastic is in the mold, it must be cooled to a temperature to which little or no dimensional change will occur after removal. In general, plastics do not conduct heat well and so will take quite a while to cool to room temperature. One way to mitigate this is to use a cold mold (thereby increasing heat loss from the part). Even so, the cooling of the part to room temperature can limit the mass production of parts.
Choosing a resin with a higher heat deflection temperature (and therefore closer to melting temperature) can allow manufacturers to achieve a much faster molding process than they would otherwise while maintaining dimensional changes within certain limits.


Design studio

A design studio or drawing office is a workplace for designers and artisans engaged in conceiving, designing and developing new products or objects. Facilities in a design studio include clothes, furniture art equipment best suited for design work and extending to work benches, small machines, computer equipment, paint shops and large presentation boards.
Size.
The size and conveniences also depends upon the type of the studio. Freelance designers engaged in product design often have a small set-up of their own, the smallest being within private residences. The ambiance of a design studio is often noted for its informality. The number of designers working in a typical design studio may vary widely, from a single individual to up to 1000 members. In such large studios, apart from designers, the staff may also consist of other technicians and artisans engaged in prototyping and engineering detailing, in addition to administrative staff and designers. They’re composed of flexible work spaces where design thinking thrives
Ownership.
The smallest studios are operated by individuals, while the medium to bigger ones may be owned and operated by manufacturers involved in consumer goods or by design firms engaged in design services catering to different firms and industries. Such independent design studios may also function as design studios as well as design firms.
Types.
Automotive design studios.
Automotive design studios are usually large, where space is required for multiple cars under development, in addition to clay modeling surface tables, large scanners and clay milling machines. Such studios also have a presentation area to accommodate at least 20 to 30 people for presentations and design briefings with clients. Automobile manufacturer studios are often treated as a separate entity and housed within a compound. Most of these design studios are often located in a different part of the city or country and are isolated from the manufacturing and engineering environment. Such studios are often high security areas, where even internal access to most areas is severely restricted.
OKB.
OKB is a transliteration of the Russian initials of "" – , meaning 'experimental design bureau'. During the Soviet era, OKBs were closed institutions working on design and prototyping of advanced technology, usually for military applications.


Ken Brock Manufacturing

Ken Brock Manufacturing, Inc. was an American aircraft manufacturer founded by Ken Brock in the 1960s and based in Stanton, California. The company specialized in the design and manufacture of autogyros in the form of kits for amateur construction, including under the US FAR 103 Ultralight Vehicles rules.
Ken Brock Manufacturing produced a number of aircraft designs including the Brock KB-1, Brock KB-2 and Brock KB-3 autogyros, plus the Ken Hovey-engineered Brock Avion ultralight aircraft. The company was also noted for the high-quality aircraft parts that it produced for other designer's aircraft, especially the Rutan Long-EZ and the Cozy Mark IV.
The company occupied a plant that included lathes, milling machines, drill presses, tap and die making, equipment for heat treating metal, plating and welding.
A subsidiary was Santa Ana Metal Stamping, which Brock set up to produce stamped metal parts using numerical control machinery.
The company closed for business at the end of 2005 after Brock's death on 19 October 2001 while landing a Thorp T-18. After his death, Brock's widow, Marie Brock, who survived the 2001 accident, attempted to sell the business and parts on hand. Aircraft Spruce & Specialty Co purchased the Cozy Mark IV parts inventory, jigs, tooling and drawings.


Electro sinter forging

Electro sinter forging (ESF) is an industrial single electromagnetic pulse sintering technique to rapidly produce a wide range of small components in metals, alloys, intermetallics, semiconductors, and composites. ESF was invented by Alessandro Fais, an Italian metallurgical engineer and scientist.
ESF is obtained by inserting loose, binder-less powders into the automatic dosing system, or manually inserted in the mold. The automatic procedure applies a pre-pressure onto the powders to ensure electrical contact; hence, it superimposes an intense electromagnetic pulse with a mechanical pulse. The two pulses last 30 to 100 ms. After a brief holding time, the sintered component is extracted by the lower plunger and pushed out by the extractor to leave room for the next sintering. Each sintering round lasts less than one second, and is carried out entirely in air (even with pyrophoric materials).


Toyota Auto Body

Toyota Auto Body  is a manufacturing subsidiary of the Toyota group based in Japan. It is headquartered in Kariya, Aichi and was established in 1945. The company has plants in the Mie and Aichi prefectures and other facilities around Japan and abroad.
The company was formed through a corporate spin-off from Toyota. In its early years, it produced auto bodies. In the late 1950s and early 1960s, it centred on truck production, before slowly switching focus to light vehicles (mostly vans) from the late 1960s onwards. In the 2000s, it absorbed the vehicle manufacturing operations of sister companies Araco and Gifu Auto Body.
As part of Toyota, Toyota Auto Body develops and produces a range of minivans, SUVs, light commercial vehicles and auto parts.
History.
Toyota Auto Body was established on 31 August 1945 as a corporate spin-off of Toyota Motor Industry's Kariya plant with the name . At first, it produced auto bodies for Toyota. In 1951, the company became the first Japanese manufacturer in producing a truck body made completely of steel. In 1953, the company adopted its present name. In January 1957, it opened an assembly facility in Kariya for mass-producing trucks. In November 1959, it created a vehicle conversion subsidiary,
Kariya Painting (later renamed Tokai Utility Motor).
In the early 1960s, Toyota gave clear functions to some of its then (subcontracting) companies: Toyota Auto Body was centred on producing trucks; Kanto Auto Works passenger vans and pickups; Arakawa Auto Body Land Cruisers and special vehicles. In 1960, Toyota Auto Body produced 74,000 trucks (including large trucks, the Stout, the ToyoAce), an 87% of Toyota's overall truck production and a 48% of its total vehicle production. In 1964, truck production from Toyota Auto Body (large trucks, the Stout, the ToyoAce, the Dyna) rose to 116,000 trucks, comprising 90% of Toyota's truck production and 27% of all vehicles.
In January 1964, Toyota Auto Body opened a second assembly facility in Kariya, the Fujimatsu plant, which produced the first Japanese hard-top car during the 1960s, the Corona Hard-top. The company also became the first in assembling mass-produced passenger cars. The production percentage of passenger cars and other light vehicles would increase for the company during the following years. In the late 1960s, Toyota Auto Body led the development of a small van with a design, similar to European ones at the time, but, according to former Toyota senior employee Akira Kawahara, something yet unseen in the Japanese industry. In 1967, Toyota Auto Body began producing the van, named as HiAce. It became the most produced model from the company with more than 6 million units . Toyota Auto Body would continue developing and producing design vans. In 1970, Toyota Auto Body production was 149,000 passenger cars and 142,000 commercial vehicles (trucks and buses), although the actual percentage declined to 17.6% of Toyota's total vehicle production.
In the 1970s, Toyota Auto Body was one of the first companies in using quality function deployment (QFD), paralleling the initial developments from Yoji Akao at Mitsubishi Heavy Industries. The rest of the Toyota group adopted the method in 1979. The improvements of Toyota Auto Body on QFD influenced Ford into adopting it.
In 1992, the company established Toyota Body Seiko, an auto parts subsidiary, and began investments to increase the production of vehicles, as the rest of its passenger car business was in decline. In December 1993, Toyota Auto Body opened the van-focused Inabe plant. By the mid-1990s, Toyota Auto Body ventured into the production of high-end passenger vans derived from the HiAce. In 1995, it started producing the Granvia, a HiAce-based semi-bonneted van made to comply with European safety regulations. From the Granvia the company developed the Alphard which was launched in 2002. In 2008, it introduced an Alphard twin vehicle, the Vellfire.
In May 2001, Toyota announced it would consolidate all production of Toyota-badged cars intended for the Japanese market into Toyota Auto Body by moving the assembly of the LiteAce/TownAce Noah and its successor (Noah) from Daihatsu. In 2004, Toyota Auto Body incorporated the auto body and vehicle production businesses from Araco. In 2005, the Kariya plant was repurposed for converting vehicles instead of producing trucks. In the fiscal year ended March 2007, Toyota Auto Body achieved its largest production volume, with about 745,000 vehicles produced during the period. In 2007, Gifu Auto Body became a wholly owned subsidiary of Toyota Auto Body.
In November 2018, Toyota announced it would transfer all van development to Toyota Auto Body. In 2019, Toyota Auto Body announced it would produce the first Lexus-badged passenger van at its Inabe plant, the Lexus LM, a badge engineered Alphard, the second Lexus product coming from the company after the Land Cruiser-based Lexus LX (the latter a legacy product from Araco).
In December 2022, Toyota Auto Body signed an agreement by which it plans to sell shares of Toyota Body Seiko to Toyota Boshoku, a minority shareholder, by October 2023, increasing the latter's ownership to a 66.4% controlling stake. After the transaction, Toyota Body Seiko would become a subsidiary of Toyota Boshoku instead of Toyota Auto Body and change its name to Toyota Boshoku Seiko. Toyota Boshoku may turn Toyota Boshoku Seiko into a wholly owned subsidiary at a later date.
In the early 2020s, the company opened specialty stores for customising and selling accessories of its produced vehicles. In January 2023, it pre-opened a Land Cruiser customisation and services store in Kariya, operated by Tokai Utility Motor, and called to be fully operational by mid-2023. In June 2023, it opened another for its commercial vehicle range in Fukagawa, Tokyo (within the Toyota Mobility Tokyo store), which is called .
Toyota Auto Body was a public company until late 2011, when Toyota made it a wholly owned subsidiary and delisted its shares.
Facilities.
Vehicle assembly and management.
Toyota Auto Body assembly plants are Fujimatsu (Ichiriyama, Kariya, Aichi), Inabe (Inabe, Mie), Yoshiwara (Yoshiwara, Toyota, Aichi), Kariya (Showa, Kariya, Aichi). There is a development centre in Toyota, Aichi (Kotobuki New Development Centre). The head offices are in Kariya, Aichi. Additional offices are located in Tokyo and Osaka.
The Fujimatsu plant covers a 436,700 square metres (m2) area and was established in January 1964. The present Kariya plant, covering 99,100 m2, was established in 1957. Both plant produce vehicles, but Fujimatsu is mostly focused on minivans and Kariya on electric vehicles. , the plants had a combined workforce of 3,139 (281 of them working at the Kariya plant). The Inabe plant is the main minivan production hub of Toyota Auto Body. It covers 800,500 m2 and was established in December 1993. , it had 2,266 employees. The Yoshiwara plant produces body-on-frame vehicles. It covers 196,200 m2 and was established in 1962. , it had 2,337 employees. By the 1999 fiscal year, all Toyota Auto Body plants got the ISO 14001 certification. The company's plants use the Toyota Production System.
Toyota Auto Body's Gifu Auto Body headquarters and facilities are in Unuma Mitsuike, Kakamigahara, Gifu. Its facilities cover 163,000 m2. , the company had 2,565 employees.
Other facilities.
 is Toyota Auto Body wholly owned research and development subsidiary. It is headquartered in Kirishima, Kagoshima and was established in 1990. Toyota Auto Body made design and development work for Toyota from the early 1960s, and, together with Toyota and sister companies, formed part of ATODE (All TOyota DEsign), a group formed in December 1960 aimed at securing a consistent styling for Toyota-badged vehicles. The Toyota Auto Body's design branch became an autonomous part of the company in 1978. The present Toyota Auto Body Research and Development subsidiary has a 5,719 m2 building and 403 employees.
Tokai Utility Motor has facilities in Anjō, Kariya, and Inabe. Toyota Body Seiko in Takahama, Toyohashi, Inabe, Kakamigahara, and two overseas plants (in China and Thailand).
Overseas subsidiaries.
Toyota Auto Body has subsidiaries in Indonesia, Taiwan, Thailand, Malaysia, China and the United States.
Most Toyota Auto Body's affiliates outside Japan are joint ventures. The Taoyuan-based Taiwanese affiliate is called Chun Shyang Shin Yeh (Industry)  and was established in 1997. It is a joint venture between Toyota Auto Body and Chun Yuan Steel, a Taiwanese steel manufacturer. The joint venture produces pressed parts, vehicle doors and suspension components for Toyota cars. Toyota Auto Body owns a 51% stake. In Thailand, Toyota Auto Body's first Thai operations began in February 1978, producing stamped parts for Hilux pickups. Toyota Auto Body Thailand officially started activities in 1979, as a stamped auto parts producer. In 1988, it formed a joint venture with Toyota Motor Thailand called Toyota (formerly Thai) Auto Works. The venture is focused on producing the HiAce. Toyota Auto Body owns a 63% stake. Both Thai ventures have plants in Samutprakan: the Samrong plant (Toyota Auto Body Thailand) and the Teparak plant (Toyota Auto Works). In 2004, Toyota Auto Body established a joint venture called Thai Auto Conversion aimed at producing specially equipped vehicles.
Toyota Auto Body also has various joint ventures in Indonesia. In 1995, it established, along with other Toyota subsidiaries, Sugity Creatives, an Indonesian joint venture headquartered in Cikarang Bekasi and aimed at producing resin components for cars. From late 2012 to 2016 it produced vehicles, including the Noah (rebadged as NAV1). Toyota Auto Body owns an 88.52% of the venture. Toyota Auto Body also has stakes in the joint ventures Toyota Auto Body-Tokai Extrusion and Resin Plating Technology, both producing auto parts. As for China, Toyota Auto Body has a 65%-owned Chinese joint venture, Tab Minth Mobility Equipment, to "sell assistive components".
The rest of the Toyota Auto Body's overseas affiliates are wholly owned subsidiaries. These are the Malaysian auto parts producer Toyota Auto Body Malaysia (established in 2005) and the American Auto Parts Manufacturing Mississippi (established in 2011).
Products.
 vehicles assembled by Toyota Auto Body include: the Alphard, the Vellfire, the Voxy, the Noah, the Land Cruiser, the HiAce, the RegiusAce, the GranAce, the Coaster, the electric vehicle COMS, the
Lexus LX and LM.
Absorbed operations.
Araco.
 was one of the first manufacturing subsidiaries of Toyota. It was established in 1946 (incorporated July 1947) at Nagoya by a former Toyota Industries sheet metal worker named Gihee Arakawa as . The company firstly made sheet metal work for Toyota, soon adding vehicle interior parts (including seats) and auto bodies. In 1953, it started assembling the Toyota BJ, and later the successive Land Cruisers. The Arakawa-assembled Land Cruiser was the main export product from Toyota in the late 1950s and early 1960s (28% of all vehicle exports in the period 1956–1964). In 1960, it entered into production the RK160B (Coaster). The company opened two new plants around Toyota City during the 1960s: Kotobuki (1960) and Yoshiwara (1962). It was renamed as in 1961, before adopting the "Araco" name in 1988. In 1995, the company began assembling Lexus vehicles. In 2004, Araco activities were split and the auto body and vehicle production operations became part of Toyota Auto Body. The vehicle interior business was merged into Toyota Boshoku.
A different Toyota subsidiary established in 1974 as was renamed as "Kyoei Araco" in 2004 and as "Araco" in 2015. This Araco specialises on seats for Lexus vehicles.
Gifu Auto Body.
 is a Gifu-based vehicle manufacturer. It was established in 1940 as a truck body manufacturer. In 1959, after receiving a big order of military vehicles from Toyota, it associated itself with the latter, producing bodies for light trucks such as the Dyna and the Stout. In the 1960s, Gifu Auto Body hand-built the Land Cruiser FJ45V, a long wheelbase variant of the third-generation Land Cruiser. Up until 1967, the company's production was focused on the Land Cruiser model and light trucks. That year, Toyota consolidated all Land Cruiser assembly in Japan into Arakawa Auto Body Industries. From 1967 onwards, the main focus of Gifu Auto Body became the production of light trucks and the HiAce until Toyota transferred truck production to Hino Motors in 1998. In January 1996, Toyota launched a civilian version of the BXD10 military vehicle called BXD20 (Mega Cruiser), and it was assembled by Gifu Auto Body. Production ended in August 2001.
By 2007, Gifu Auto Body was producing the HiAce and auto parts (pressed parts and truck seats). That year, it became a wholly owned subsidiary of Toyota Auto Body through stock swap. In July 2015, Gifu Auto Body transferred its auto parts business to Toyota Body Seiko in order to focus on commercial vehicle assembly. In December 2016, Toyota Auto Body moved production of the Coaster from its Yoshiwara plant to Gifu Auto Body.
Sports.
An Araco team entered Land Cruisers into the Rally Dakar from 1995 onwards. In 2005, the team was renamed as . , it achieved ten consecutive victories in the diesel production car class. The company entered a HiAce into the 2023 Toyota Gazoo Racing Rally Challenge. The HiAce rally version was built on a GDH201V chassis modified by Cast (a HiAce tuning division of the Sanko Works company) and it is run by Toyota Auto Body's own team, . Cast had already entered a couple of HiAces into the 2021 All-Japan Rally Championship.
Toyota Auto Body has two company teams participating in Japanese national sports championships: the volleyball team Toyota Auto Body Queenseis and the handball team Toyota Auto Body Brave Kings.
, Gifu Auto Body is sponsor of FC Gifu.


Labour Inspection Convention, 1947

Labour Inspection Convention, 1947 is an International Labour Organization Convention.
It was established in 1947 with the preamble stating:
Having decided upon the adoption of certain proposals with regard to the organisation of labour inspection in industry and commerce...
Ratifications.
As of 2021, 148 of the 186 ILO states had ratified the convention.


W.W. (automobile)

W.W. (Winter), was an early British car made by Winter and Company of Wandsworth, London. They made two models between 1913 and 1914.
The first car, the W.W. of 1913 was a light car powered by an 8 hp V-twin engine bought in from the Precision company. This drove the rear wheels through a gear box by Chater-Lea and shaft drive to a worm gear final drive on the rear axle.
For 1914 production changed to a cyclecar. This was sold as a Winter and had a Blumfield engine and friction drive with belt to the rear axle.
The number made is not known.


Surface micromachining

Surface micromachining builds microstructures by deposition and etching structural layers over a substrate. This is different from Bulk micromachining, in which a silicon substrate wafer is selectively etched to produce structures.
Layers.
Generally, polysilicon is used as one of the substrate layers while silicon dioxide is used as a "sacrificial layer." The sacrificial layer is removed or etched out to create any necessary void in the thickness direction. Added layers tend to vary in size from 2-5 micrometres. The main advantage of this machining process is the ability to build electronic and mechanical components (functions) on the same substrate. Surface micro-machined components are smaller compared to their bulk micro-machined counterparts.
As the structures are built on top of the substrate and not inside it, the substrate's properties are not as important as in bulk micro-machining. Expensive silicon wafers can be replaced by cheaper substrates, such as glass or plastic. The size of the substrates may be larger than a silicon wafer, and surface micro-machining is used to produce thin-film transistors on large area glass substrates for flat panel displays. This technology can also be used for the manufacture of thin film solar cells, which can be deposited on glass, polyethylene terepthalate substrates or other non-rigid materials.
Fabrication process.
Micro-machining starts with a silicon wafer or other substrate upon which new layers are grown. These layers are selectively etched by photo-lithography; either a wet etch involving an acid, or a dry etch involving an ionized gas (or plasma). Dry etching can combine chemical etching with physical etching or ion bombardment. Surface micro-machining involves as many layers as are needed with a different mask (producing a different pattern) on each layer. Modern integrated circuit fabrication uses this technique and can use as many as 100 layers. Micro-machining is a younger technology and usually uses no more than 5 or 6 layers. Surface micro-machining uses developed technology (although sometimes not enough for demanding applications) which is easily repeatable for volume production.
Sacrificial layers.
A sacrificial layer is used to build complicated components, such as movable parts. For example, a suspended cantilever can be built by depositing and structuring a sacrificial layer, which is then selectively removed at the locations where the future beams must be attached to the substrate (i.e. the anchor points). A structural layer is then deposited on top of the polymer and structured to define the beams. Finally, the sacrificial layer is removed to release the beams, using a selective etch process that does not damage the structural layer.
Many combinations of structural and sacrificial layers are possible. The combination chosen depends on the process. For example, it is important for the structural layer not to be damaged by the process used to remove the sacrificial layer.
Examples.
Surface Micro-machining can be seen in action in the following MEMS (Microelectromechanical) products:


Bulk micromachining

Bulk micromachining is a process used to produce micromachinery or microelectromechanical systems (MEMS).
Unlike surface micromachining, which uses a succession of thin film deposition and selective etching, bulk micromachining defines structures by selectively etching inside a substrate. Whereas surface micromachining creates structures "on top" of a substrate, bulk micromachining produces structures "inside" a substrate.
Usually, silicon wafers are used as substrates for bulk micromachining, as they can be anisotropically wet etched, forming highly regular structures. Wet etching typically uses alkaline liquid solvents, such as potassium hydroxide (KOH) or tetramethylammonium hydroxide (TMAH) to dissolve silicon which has been left exposed by the photolithography masking step. These alkali solvents dissolve the silicon in a highly anisotropic way, with some crystallographic orientations dissolving up to 1000 times faster than others. Such an approach is often used with very specific crystallographic orientations in the raw silicon to produce V-shaped grooves. The surface of these grooves can be atomically smooth if the etch is carried out correctly, and the dimensions and angles can be precisely defined. Pressure sensors are usually created by bulk micromachining technique.
Bulk micromachining starts with a silicon wafer or other substrates which is selectively etched, using photolithography to transfer a pattern from a mask to the surface. Like surface micromachining, bulk micromachining can be performed with wet or dry etches, although the most common etch in silicon is the anisotropic wet etch. This etch takes advantage of the fact that silicon has a crystal structure, which means its atoms are all arranged periodically in lines and planes. Certain planes have weaker bonds and are more susceptible to etching. The etch results in pits that have angled walls, with the angle being a function of the crystal orientation of the substrate. This type of etching is inexpensive and is generally used in early, low-budget research.
External links.


Cartesian coordinate robot

A Cartesian coordinate robot (also called linear robot) is an industrial robot whose three principal axes of control are linear (i.e. they move in a straight line rather than rotate) and are at right angles to each other. The three sliding joints correspond to moving the wrist up-down, in-out, back-forth. Among other advantages, this mechanical arrangement simplifies the robot control arm solution. It has high reliability and precision when operating in three-dimensional space. As a robot coordinate system, it is also effective for horizontal travel and for stacking bins.
Configurations.
Robots have mechanisms consisting of rigid links connected together by joints with either linear (prismatic "P") or rotary (revolute "R") motion, or combinations of the two.  Active prismatic "P" and active revolute "R" joints are driven by motors under programmable control to manipulate objects to perform complex automated tasks. The linear motion of active prismatic "P" joints may be driven by rotary motors through gears or pulleys. Cartesian coordinate robots are controlled by mutually active prismatic "P" joints that are aligned with the "X, Y, Z" axes of a Cartesian coordinate system.  Although not strictly ‘robots’, other types of manipulators, such as computer numerically controlled (CNC) machines, 3D printers or pen plotters, also have the same mechanical arrangement of mutually perpendicular active prismatic "P" joints.
Joint topology.
A single chain of links and joints connects a moving object to a base of serial manipulators. Multiple chains (limbs) connect the moving object to the base of parallel manipulators.  Most Cartesian coordinate robots are fully serial or a combination of serial and parallel connected linkages.  However, there are some Cartesian coordinate robots that are fully parallel-connected.
Degrees of freedom.
Since they are driven by linear active prismatic "P" joints, Cartesian coordinate robots typically manipulate objects with only linear translation "T" degrees of freedom.  However, some Cartesian coordinate robots also have rotational "R" degrees of freedom.
Construction.
Each axis of a Cartesian coordinate robot typically is a linear stage consisting of a linear actuator geometrically parallel with linear bearings. The linear actuator is typically between two linear bearings spaced apart from each other to support moment loads.  Two perpendicular linear stages stacked on top of each other form an XY table.  Examples of XY tables include the XY axes of milling machines or precision positioning stages. At least one of the linear stages of cantilevered Cartesian coordinate robots is supported at only one end. Cantilevered construction provides accessibility to parts for pick-and-place applications such as laboratory automation for example. Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called gantry robots; mechanically, they resemble gantry cranes, although the latter are not generally robots. Gantry robots are often quite large and may support heavy loads.
Applications.
Popular applications for Cartesian coordinate robots are computer numerical control machines (CNC machine) and 3D printing. The simplest application is used in milling machines and plotters where a tool such as a router or pen translates across an "X-Y" plane and is raised and lowered onto a surface to create a precise design.
Pick and place machines are another application for Cartesian coordinate robots.  For example, overhead gantry Cartesian robots are applied for continuous parts loading and unloading on CNC lathes production lines, performing 3-axis "(X, Y, Z)" pick and place operations of heavy loads with high speed performance and high positioning accuracy.  In general, overhead gantry Cartesian robots are suitable for many automation systems.