10 WAYS TO AVOID COMMON HEAD BOLT TORQUING MISTAKES

1. Make sure all the head bolts are in perfect condition with clean, undamaged threads. Dirty or damaged threads can give false torque readings as well as decrease a bolt's clamping force by as much as 50%! Wire brush all bolt threads, carefully inspect each one, and replace any that are nicked, deformed or worn.
2. Dirty or deformed hole threads in the engine block can reduce clamping force the same as dirty or damaged threads on the bolts. Run a bottoming tap down each bolt hole in the block. The tops of the holes should also be chamfered so the uppermost threads won't pull above the deck surface when the bolts are tightened. Finally, clean all holes to remove any debris.
3. For head bolts that screw into blind holes, lightly lubricate the bolt threads as well as the underside of the bolt heads with engine oil. For head bolts that extend into a coolant jacket, coat the threads with a flexible sealer such as Fel-Pro Gray Bolt Prep (GRA2). Failure to coat the threads may allow coolant to leak past the bolt.
4. Many engines today use "torque-to-yield" (TTY) head bolts. These are specially designed bolts that stretch slightly when installed. This provides more even head loading and allows the bolts to hold torque better for improved head gasket sealing.
When the bolts are installed, they're first tightened to a specific torque -- then tightened an additional amount that's measured in degrees of rotation. This final twist stretches the bolts to their yield point and creates the elastic clamping force that provides more even loading across the head and gasket. Because TTY head bolts stretch slightly (only a few thousandths of an inch), some auto makers say they should not be reused when the cylinder head is removed. Reusing TTY bolts will cause them to stretch further, which increases the risk of breakage.
A stretched bolt also will not hold the same torque load as before, which may cause a loss of clamping force resulting in head gasket leakage. Ford says TTY head bolts on the 1.6L Escort engine should not be reused. Though not required, it may be wise to replace TTY head bolts on other engines if the vehicle manufacturer doesn't say to do so. Replacement TTY head bolts are available from Fel-Pro, and are recommended for Chrysler 2.2L and 2.5L, Ford 1.6l and 1.9L, and GM 1.8L, 2.0L and 2.5L fours, 3.0L V6 and 381 V8 diesel engines.
5. Check bolt lengths. Make sure you have the correct length bolts for the application and for each hole location (some holes require longer or shorter bolts than others). Bolts should also be measured or compared to one another to check for stretch. Any bolt found to be stretched must be replaced because (1) it may be dangerously weak, (2) it won't hold torque properly, and (3) it may bottom out when installed in a blind hole.
6. When installing head bolts in aluminum cylinder heads, hardened steel washers must be used under the bolt heads to prevent galling of the soft aluminum and to help distribute the load. Make sure the washers are positioned with their rounded or chamfered side up, and that there is no debris or burrs under the washers.
7. Resurfacing a cylinder head decreases its overall height, so be sure to check bolt lengths to make sure they won't bottom out in blind holes. If a bolt bottoms out, it will apply little or no clamping force on the head which may allow the gasket to leak. If a head has been milled and one or more head bolts may be dangerously close to bottoming out, the problem can be corrected by either using hardened steel washers under the bolts to raise them up, or by using a Fel-Pro copper head gasket shim in conjunction with the new head gasket to restore proper head height.
8. Always look up the specified tightening sequence and recommended head bolt torque values for an engine before installing the head gasket. Never guess. Complete cylinder head torque specifications for domestic and import vehicles are published in Fel-Pro's "Torque Tables" (486-93).
9. Use an accurate torque wrench to tighten standard type head bolts in 3 to 5 incremental steps following the recommended sequence and torque specs for the application. Tightening the bolts down gradually creates an even clamping force on the gasket and reduces head distortion. It's a good idea to doublecheck the final torque readings on each head bolt to make sure none have been missed and that the bolts are retaining torque normally. If a bolt is not coming up to normal torque or is not holding a reading, it means trouble. Either the bolt is stretching or the threads are pulling out of the block. With TTY head bolts, a "Torque-To-Angle Indicator" such as Fel-Pro's TRQ-1 should be used in conjunction with a torque wrench to achieve proper bolt loading. After the head bolts have been torqued to the specified value, using the TRQ-1 tool to accurately measure the additional degrees of additional rotation eliminates guesswork and assures more consistent results.
10. PermaTorque head gaskets do not require retorquing, but some head gaskets for import applications do. If a gasket requires retorquing, run the engine until it reaches normal operating temperature (usually 10 to 15 minutes), then shut it off. Retighten each head bolt in the same sequence as before while the engine is still warm. If the engine has an aluminum cylinder head or block, however, don't retorque the head bolts until the engine has cooled back down to room temperature.
On some applications with retorque style head gaskets, it may be necessary to retorque the head a third time after a specified time or mileage interval due to the design of the engine. Follow the vehicle manufacturer's recommendations.

HOW TO PREVENT HEAD GASKET FAILURES CAUSED BY LOW CLAMPING FORCE

When a head gasket is installed between the cylinder head and engine block, tightening the head bolts compresses the gasket slightly allowing the soft facing material on the gasket to conform to the small irregularities on the head and block deck surfaces. This allows the gasket to "cold seal" so it won't leak coolant before the engine is started.
The head gasket's ability to achieve a positive cold seal as well as to maintain a long-lasting leak-free seal depends on two things: its own ability to retain torque over time (which depends on the design of the gasket and the materials used in its construction), and the clamping force applied by the head bolts.
Fel-Pro "PermaTorque^®" head gaskets are made with top quality materials and designed to remain resilient so they retain torque. That's why retorquing isn't necessary (some competitive head gaskets that are claimed to be "no retorque" can lose as much as 50 to 60% of their original torque after only 100 hours of service!). But even the best head gasket won't hold and maintain a tight seal if the head bolts have not been properly torqued. The amount of torque that's applied to the bolts as well as the order in which the bolts are tightened determine how the clamping force is distributed across the surface of the gasket. If one area of the gasket is under high clamping force while another area is not, it may allow the gasket to leak at the weakly clamped point. So the head bolts must all be tightened in a specified sequence and equally torqued to a specified value to assure the best possible seal.
Another consequence of failing to torque the head bolts properly can be head warpage. Uneven loading created by unevenly tightened head bolts can distort the head. Over a period of time, this may cause the head to take a permanent set. So any head that has not been properly torqued should be checked for flatness prior to installing a new head gasket.

Heat Transfer in Continuous Casting

By its nature, continuous casting is primarily a heat-extraction process. The conversion molten metal into a solid semi-finished shape involves the removal of the following forms of heat:

- superheat from the liquid entering the mould from the tundish.
- the latent heat of fusion at the solidification front as liquid is transformed solid, and finally
- the sensible heat (cooling below the solidus temperature) from the solid shell

These heats are extracted by a combination of the following heat-transfer mechanisms:

- convection in the liquid pool.
- heat conduction down temperature gradients in the solid shell from the solidification
   front to the colder outside surface of the cast, and
- external heat transfer by radiation, conduction and convection to surroundings.

Also not less important is heat transfer before the molten metal is poured into the mould. or instance, in the casting of steel, heat transfer is important before the steel enters the mould because control of superheat in the molten steel is vital to the attainment of a predominantly equiaxed structure and good internal quality. Thus, conduction of heat into ladle and tundish linings, the preheat of these vessels, convection of the molten steel and heat losses to the surroundings also play an important role in continuous casting.

Because heat transfer is the major phenomenon occurring in continuous casting, it is also the limiting factor in the operation of a casting machine. The distance from the meniscus to the cut-off stand should be greater than the metallurgical length, which is dependent on the rate of heat conduction through the solid shell and of heat extraction from the outside surface, in order to avoid cutting into a liquid core. Thus, the casting speed must be limited to allow sufficient time for the heat of solidification to be extracted from the strand.

Heat transfer not only limits maximum productivity but also profoundly influences cast quality, particularly with respect to the formation of surface and internal cracks. In part, this is because metals expand and contract during periods of heating or cooling. That is, sudden changes in he temperature gradient through the solid shell, resulting from abrupt changes in surface heat extraction, causes differential thermal expansion and the generation of tensile strains. Depending on the magnitude of the strain relative to the strain-to-fracture of the metal and the proximity' of the strain to the solidification front, cracks may form in the solid shell. The rate of heat extraction also influences the ability of the shell to withstand the bulging force due to the ferrostatic pressure owing to the effect of temperature on the mechanical properties of the metal. Therefore, heat transfer analysis of the continuous casting process should not be overlooked in the design and operation of a continuous casting machine.

Piston Pin sample data

1	Material Specification
		DIN 17210 - 16MnCr5                                                                                             DIN 17210 - 15Cr3                                                                                        Similar to ASTM A322 Designation 5015
2	Heat Treatment
		Case Hardened and Tempered                                                                                Surface Hardness : 57 + 8 HRC,  635 + 195 HV10                                                                  Case Depth : 0.5 + 0.6 mm
		Hardness Penetration Depth Limit : 500 HV1
3	Maximum Permissible Dimetral Growth
		0.012 mm after stabilising for 72 hours at 220 deg C.
4	Dimensional Details
		OD = 35 mm +0.000 / -0.006 mm                          for 35 mm h4 = -0.007 mm
		ID = 18 mm +0.3 / -0.3 mm                                   for 18 mm, js14 = +/- 0.215, js15 = +/- 0.390 mm
		Length = 80 mm +0.0 / 0.5 mm                             for 80 mm, h13 = -0.460 mm
		OD Corner Radii = 0.6 mm +/- 0.1 mm
		ID Edge chamfer = 1 x 45 deg.
5	Form tolerances
		ID to be concentric within DIA 0.4 wrt OD              for 35 OD, IT13 = 0.390 mm
		OD roundness 0.002 mm                                     1/3 OD Tolerance
		OD Straightness 0.004 mm                                  2/3 OD Tolerance
6	Surface Finish
		OD = Fine lapped, Rp 0.25 max as per DIN 4762 Part 1 (Measured according to 'M' system)
		ID = Rz 25
		unspecified Surfaces Rz 100
		Conversions : Rz 100 = Ra 30
		Rz 25 = Ra 6.3

Segregation in Cast Products

References
Basu B, Singh A K 1997 Role and characterization of double-diffusive convection during
solidification of binary alloys. Proc. 3rd ISHMT–ASME Heat & Mass Transfer Conf. and 14th
Natl. Heat & Mass Conf., IIT, Kanpur, pp 129–141
Bergman M I, Fearn D R, Bloxham J, Shannon M C 1997 Convection and channel formation in
solidifying Pb–Sn alloys. Metall Mater. Trans. A28: 859–866
Choudhary S K, Ghosh A 1994 A study of morphology and macrosegregation in continuously cast
steel billets. Iron Steel Inst. Jap. Int. 34: 338–345
Choudhary S K, Mazumdar D 1995 Mathematical modelling of fluid flow, heat transfer and
solidification phenomena in continuous casting of steel. Steel Res. 66: 199–205
Flemings M C 1974 Solidification processing (New York: McGraw Hill)
Flemings M C 1990 Segregation in castings and alloys. Proc. Elliott Symp. (Iron & Steel Soc) pp
216–235
Flood S C, Hunt J D 1988 Columnar to equiaxed transition. Metals handbook 9th edn (Am. Soc.
Mater. Int.) vol. 15, pp 130–136
Fredriksson H, Olsson A 1986 Mechanism of transition from columnar to equiaxed zone in ingots.
Mater. Sci. Technol. 2: 508–516
Ghosh A 1990 Principles of secondary processing and casting of liquid steel (New Delhi: Oxford &
IBH) ch. 6,7 & 9
Ghosh A 1997 Fundamental aspects of segregation control in continuous casting of steel. Proc. Int.
Symp. on Quality Challenges in Continuous Casting (Ranchi: Indian Inst. Metals), pp 203–218
Goyal R K, Ghosh A 1992 Centreline segregation in continuously cast steel billets. Trans. Indian
Inst. Metals 45: 303–314
Gu J P, Beckermann C 1999 Simulation of convection and macrosegregation in a large steel ingot.
Metall. Mater. Trans. A30: 1357–1367
Lacaze J, Lesoult G 1999 Modelling and development of microsegregation during solidification of
an Al–Cu–Mg–Si alloy. Iron Steel Inst. Jap. Int. 39: 658–664
Li M, Mori T, Iwasaki H 1999 Effect of solute convection during macrosegregation in Pb–Sn binary
alloys during upward directional solidification. Iron Steel Inst. Jap. Int. 39: 33–38
Lipton J, Kurtz W, Heinemann W 1983 Concast Tech. News 22: 4
Miyazawa K, Schwerdtfeger K 1981 Macrosegregation in continuously cast steel slabs –
preliminary theoretical investigation on the effect of steady state bulging. Arch. Eisenw. 52:
415–422
Moore J J 1984 Review of axial segregation in continuously cast steel. Continuous casting (ed.) J J
Moore (Iron & Steel Soc.) vol. 3, pp 11–20
Ohnaka I 1988 Microsegregation and macrosegregation. Metals handbook 9th edn (Am. Soc. Mater.
Int.) vol. 15, pp 136–141
Prescott P J, Incropera F P 1996 Convection heat and mass transfer in alloy solidification. Adv. Heat
Transfer 28: 231–328
Radovik Z, Lalovic M, Tripkovic M, Branislav J 1999 Forming of positive macrosegregation during
steel ingot solidification. Iron Steel Inst. Jap. Int. 39: 329–334
Roy T K, Choudhary S K, Ghosh A 1992 Tool and alloy steels pp 365–372
Schneider M C, Beckermann C 1995 Simulation of micro-/microsegregation during solidification of
a low-alloy steel. Iron Steel Inst. Jap. Int. 35: 665–672
Singh A K, Basu B 1995 Mathematical modelling of macrosegregation of iron carbon binary alloy:
role of double diffusive convection. Metall Mater. Trans. B26: 1069–1081
Singh A K, Basu B 2000 On convection in mushy phase and its effect on macrosegregation. Metall.
Mater. Trans. A31: 1687–1692
Tsuchida Y et al 1984 Trans. Iron Steel Inst. Jap. 24: 899
Yamada H, Takenouchi T, Takahashi T, Funazaki M, Iwadate T, Nakada S. 1995 Influence of
alloying elements on the segregation of high purity CrMoV steel. Iron Steel Inst. Jap. Int. 35:
686–692

GstarCAD Launches Application for iTouch and iPhone

GstarCAD, an industry leading 2D/3D software provider has newly launched GstarCAD MC 1.1 for Apple's iPad, iTouch and iPhone, 3 weeks after its early release of GstarCAD MC 1.0 for iPad.

The new version of GstarCAD MC aims at wider range of iPhone customers. iPhone's better portability and stronger communication functions enable users to access drawings via GstarCAD MC on more special occasions, which bring more convenience and flexibility. 


In addition, some very practical functions like full-screen display and customized GUI setting are added on the base of GstarCAD MC 1.0. Taking GUI setting as example, GstarCAD MC 1.1 allows users to customize the user interface, e.g. background color, size and location of Magnifier, maximum number of selected entities, to fit their operational habits. The settings are able to be saved and recalled without repetitive work. Moreover, the enhancement in performance is another highlight of GstarCAD MC 1.1. GstarCAD MC 1.1 inherits the powerful functions of GstarCAD MC 1.0 and ameliorates them. The improvements ensure the finger-operations smoother and quicker, comparing to other applications.


About GstarCAD
GstarCAD is the fast, powerful and DWG-compatible CAD software for the industries involving AEC, mechanical, manufacturing, electrical, GIS, survey and mapping, civil, etc. It is the world-class 2D/3D CAD (Computer aided design) software platform based on IntelliCAD technology. GstarCAD's powerful functions, dwg-compatible programming platform, cost-effective solution and ease-of-use operating interface ensure that your design inspiration comes true skillfully and thoroughly at high speed.

DXF

DFX, or design for X, can be defined as a knowledge-based approach that attempts to
design products that maximize all desirable characteristics—such as high quality, reliability,
serviceability, safety, user friendliness, environmental friendliness, and short
time-to-market—in a product design while at the same time minimizing lifetime costs,
including manufacturing costs.
Historically, designers have tended to underemphasize or overlook the preceding
factors and have concentrated their efforts on only three factors: the function (performance),
features, and appearance of the product that they develop. They have tended
to neglect the “downstream” considerations that affect the usability and cost of the
product during its lifetime.
AT&T Bell Laboratories recognized the need to satisfy these objectives and used
the term DFX to designate designing for all desired factors.2 DFX was described as a
design procedure in which the objective broadly covers cost-effective “downstream”
operations: distribution, installation, service, and customer use. Reliability, safety,
conformance to environmental regulations, and liability prevention are also objectives.
These are in addition to low manufacturing costs. DFX is “the process where the full
life-cycle needs of the product are addressed during the product’s design.” AT&T
made note of the value of incorporating DFX knowledge into CAE/CAD (computeraided
engineering/computer aided design). Education was stated to be essential.3
THE ATTRIBUTES OF A GOOD DESIGN
The following design objectives have been recommended as being most important.
Function and Performance
These are still vital. The product must perform the task for which it is designed.

Safety
Those involved in the manufacture, sale, and use of the product and other persons
must be protected from physical injury and illness. A sound design from the safety
standpoint is one whose manufacturing process does not involve hazards to workers; it
is one whose operation poses the minimum risks to the user and those in the vicinity;
it is one which, when the product is discarded after its useful life, does not entail hazardous
waste.
Long-Term Quality
That is, quality, reliability, and durability (the customer tends to group these objectives
together; the designer should also). Will the product continue to provide its
desired function over a period of time? Will it retain its appearance, its accuracy, its
ease of use, etc.? Quality and reliability result from care and attention at a number of
stages, but perhaps the most important stage is the design stage. Quality and reliability
cannot be built in if the basic design is not conducive to them.
Manufacturability
This includes testability, shipability, etc.—all the objectives of DFM.
Environmental Friendliness
This is closely related to safety but affects all living creatures and plant life. Will the
product, its manufacturing process, its use, and its disposal avoid the release of pollutants
and other environmental hazards? The manufacturing process should be one that
generates minimal pollution. The product itself should be nonpolluting and, as noted
above, nonhazardous in its operation and disposal. Even if nonhazardous, are its components
configured so that they can be recycled easily? Design for the environment
(DFE) has been used as a term to describe this approach. Design for disassembly is the
name given to the system of product design that emphasizes recyclability of components.
Primarily, this involves designs that ensure that recyclable components can be
separated easily from the rest of the product.
Serviceability (Maintainability and Repairability)
This involves the ease with which the product can be returned to use after some failure
has occurred, or the ease with which it can be attended to to avoid future failures. This
objective is closely related to reliability. Easy serviceability may compensate for what
otherwise would be a reliability problem.

User Friendliness, or Ergonomics
This involves how well the product fits its human users, how easy it is to use. (Human
factors engineering was a previously common term for the discipline that this
involves.) Is the product easy for the user to install and operate? Are all functions and
controls clear? User unfriendliness can lead to safety and reliability problems as well
as make the product less functional.
Appearance (or Aesthetics)
This is the attractiveness of the product, which may be a very important factor in its
salability, particularly with many consumer products.
Features
The accessories, attachments, and peripheral functions, like the stereo, air-conditioning,
and cruise control in an automobile, may be more important to the buyer than its
basic function, i.e., in the case of an automobile, transportation.
Short Time-to-Market
This is how suitable the design is for short lead-time production. This normally means
whether the design is one that requires unique long lead-time tooling for some of its
components. Short time-to-market has important implications in the current era where
product designs change rapidly and where commercial success often hinges on being
the first supplier to market a product with particular features. The company that puts
an innovation on the market first often reaps ongoing benefits in the form of increased
market share for its product.
Other objectives such as installability, testability, shipability, upgradeability, easy
customizing, etc., also may be important in many cases.

REFERENCES
1. James G. Bralla, Design for Excellence, DFX, McGraw-Hill, New York, 1996.
2. David A. Gatenby, “Design for `X’ (DFX): Key to Efficient, Profitable Product Realization,”
in J. A. Edosomwan and A. Ballakur (eds.), Productivity and Quality Improvement in
Electronics Assembly, McGraw-Hill, New York, 1989, Chap. 45.
3. R. A. Layendecker and B. Suing Kim, “From DFMA to DFX: An AT&T Example,” paper presented
at the 1993 DFM Conference at the National Design Engineering Conference, Chicago,
March 1993.

Lubricants

The lubricant’s main duty is to diminish the influence of friction
between the tooling and the material. Ideally, lubricants should also act as a coolant and
thermal insulator, while not being causative of any detrimental action against the tooling or
the material, the press equipment or the operator. The lubricant should not cause rusting of
metal parts, and should be easily removable by some accessible means.
Lubricants are of utmost importance in forming and drawing processes, where these can
be divided into two categories, based on the type of lubricants used:
• Wet drawing or forming, using mineral oils, vegetable oils, fat, fatty acids, soap, and water
• Dry drawing or forming, using metallic coatings (Cu, Zn, brass) with graphite or emulsions,
Ca-Na stearate on lime, borax or oxalate, chlorinated wax or soap phosphate
In metal forming, the danger of entrapping the lubricant with the fast action of the tooling
presents additional possibilities of surface deformation. Usually, areas affected by a
restrained lubricant display a sudden roughness, often resembling a matte finish.
Lubricating Components. The actual process of lubrication is provided by several
basic ingredients. These are:
• Mineral oils, which are petroleum derivates, such as motor oil, transmission fluid, and
SAE-oils.
• Water-soluble oils, which are a combination of mineral oils, adjusted by an addition of
other elements to become emulsifiable with water.
• Fats and fatty oils, most often of vegetable or animal origin, such as lard, fish oil, tallow,
all vegetable oils, and beeswax.

Fatty acids, such as oleic and stearic acids, generated from fatty oils.
• Chlorinated oils, a combination of fatty oils and chlorine.
• Soaps, which are basically water-soluble portions of fatty acids, combined with the alkali
metals.
• Metallic soaps, which are insoluble in water, such as aluminum stearate and zinc stearate.
• Sulfurized oils, or hydrocarbons, treated with sulfur.
• Pigments, such as graphite, talc, or lead. These are actually minute particles of solids, not
soluble in water, fats, or oil. They are often supplied in a mixture of oils or fats, which
provide for their retention and spreading.
These ingredients when added into but three groups of compounds form a metal-forming
lubricant. These compounds are as follows:
• Base material, a carrier.
• Wetting or polarity agent.
• Parting agent, or an extreme-pressure agent.
For example, in drawing process, the carrier may be oil, solvent, water, or a combination
of several compounds. The wetting agent often consists of emulsifiers, animal fats or
fatty acids, or long chain polymers. The parting agent, where added, is chlorine, sulfur, or
phosphorus. Also added may be physical barriers, such as graphite, talc, and mica.
It is expected of a lubricant to be able to control friction, prevent galling, dissipate heat,
and reduce tool wear. The dissipation of heat depends on the function and properties of the
carrier. All the additional qualities and properties depend on the other ingredients and on
that particular lubricant’s mechanism.
According to the lubricating mechanism, there are three basic types that are being used:
1. Hydrodynamic lubrication, or fluid film lubrication. This type of lubrication works well
where the lubricating film is not disrupted by an increase in temperature or speed. It is
efficiently used for lubricating of auto engines, but unfortunately, in metal stamping and
metal forming it has not found an application yet.
2. Boundary lubrication occurs where the lubricant is combined with surfactants, also
called wetting agents or polar additives. These become attracted to the surface of metal
of the tooling and that of the sheet-metal material as well, acting as a protective layer of
these surfaces. Surfactants can be soaps, their base carrier being fat, oil, fatty alcohols,
and the like. This type of lubricant further benefits from its enhanced wetting capacities.
Of disadvantage are the temperature-related functionality limits, which top off with
100°C, or a boiling point of water.
3. EP lubricants can be chemical or mechanical. In chemical EP form, chlorinated hydrocarbons
are added to stamping lubricants, where they form protective metallic salts on the
surface of the part and its tooling. During the stamping process, the heat of the operation
forces the released chlorine to interact with iron and the resulting iron-chloride film
becomes the actual lubricant. Where sulfur is used in the lubricating base (i.e., carrier),
the chemical reaction produces an iron-sulfide film. Mechanical EP lubricants’ additives
are molybdenum disulfide and calcium carbonate. The disadvantage of this lubricant
type lies in the buildup it leaves on the part and on the tooling, which can affect some
sensitive portions of the tool and cause their breakage.
A fourth type of lubricating mechanism exists in the form of various combinations of
the above-described three methods.

Many materials used in the production of electronics are incompatible with the third, EP
method of lubrication. With bronze, beryllium copper, or phosphor bronze materials, their
surfaces do not respond well to these lubricants. Actually, where sulfur is being used, staining
of some alloys may occur. For this reason, a boundary method of lubrication using a
combination of chlorine and fatty materials is preferable.
According to their basic component, lubricants can be further divided into:
• Oil-based
• Water-based
• Solvent-based
• Synthetic
• Dry-film
Oil-based lubricants are useful for processes where high loads are present. These are
petroleum-based lubricants and their applications include punching, blanking, coining,
embossing, extruding, some demanding forming operations, and drawing.
Water-based lubricants may sometimes contain oils as well, with which they form
emulsions. These lubricants are easier to remove from the surface of parts than those based
on petroleum. Lately this type of lubricating approach is becoming quite popular, since the
performance of some heavy-duty types are on par with petroleum-based products. Waterbased
lubricants are well suited for progressive dies, transfer presses, and for drawing
operations.
Solvent-based lubricants are of importance where the basic sheet-metal material is
already coated, such as vinyl-coated materials, lacquered and painted surfaces, or laminates.
In some instances, these lubricants do not require any cleaning nor degreasing afterwards,
for which advantage they are preferred for manufacture of appliances, electrical
hardware, and similar components.
Synthetic lubricants are very easy to clean, as they usually consist of solutions of chemicals
in water. These can be used on coated surfaces, with vinyl-clad parts, painted parts, or
aluminum. Many synthetic lubricants are biodegradable and as such they do not possess
any environment-harming qualities.
Dry-film lubricants previously consisted of high melting point soaps. Some new types
that emerged on the market are synthetic esters and acrylic polymers. These produce good
results where applied to blanks or strips of sheet-metal material. Of a distinct advantage is
their cleanliness, ease of handling and performance. Unfortunately, their cost is not always
compatible with the requirements of the metal stamping industry, which is further complemented
by their inability to dissipate heat of the operation.
As a rule, with all lubricants, their use and methods of application must be compatible
with those they were developed for. Where a wrong lubricant should be used, the results of
such manufacturing operation may be pitiful. Therefore, the lubricant’s characteristics
must be fully understood and tried out prior to production, to make sure these will be used
only for processes they were intended for.

Types of Friction

 In metal fabricating, various materials, in combination with
different types of lubricants, or in the absence of the same, will generate three basic types
of friction:
• Static, or dry friction—created between two metallic surfaces with no lubricant added.
The friction mechanism depends on the physical properties of the two materials in contact.
A metallic lubricant (for example, lead, zinc, tin, or copper) may improve this condition.
• Boundary friction––where two surfaces are separated by a layer of nonmetallic lubricant
a few molecules thin. The shear strength of the lubricating material is low, resulting in
low friction.
• Hydrodynamic friction—where two surfaces are totally separated by a viscous lubricant
of hydrodynamic qualities. In such a case, friction depends strictly on the properties of
the lubricant.
• Combined friction—or a mixture of the above conditions. This type of friction is the most
frequently encountered in metal-forming processes.
Out of all metal-forming processes, only a few do not require any surface treatment or
coating when it comes to friction. These are: Open-die-forming, spreading, some bending
operations, and extrusion of easily deformable materials. All other metal forming depends
on the use of proper lubricants. Even die forging requires a surface treatment of raw material;
in this case for the protection of the die itself.

Friction in Forming and Drawing

Friction in metal stamping can have many beneficial as well as detrimental effects on the
tooling and quality of produced parts. It increases the surficial pressure between the tool
and sheet-metal material, which results in deformation of both, with subsequent degradation
of surface quality and wear of tooling. This increases the demand for press force, often
considerably escalating its levels.
Since the area of contact between the part and its tooling constantly changes, the distortion
and degradation of surface affects a widespread portions of both. The roughing
effect on the surface of tooling causes the actual contact areas to diminish in size and
become localized, which subsequently increases the frictional influences in each such segment,
and a faster deterioration of the tooling and parts follows.
The heat along with the damaging effect of surficial pressure, tears out small portions
of sheet-metal material, attaching it permanently to the tooling or elsewhere within the area
of contact. Such small pieces are as if welded; they are difficult to remove and their presence
further affects the quality of parts, their dimensional accuracy, and the condition of
tooling. For example, the force needed to overcome friction during the backward extrusion
of a cup was found to amount to approximately 40 percent of the total force exerted by the
punch.
The problem of friction is quite complex and cannot be readily solved. On the other hand,
some processes, such as metal forming depend on a certain amount of friction, the removal of
which may not be beneficial to the forming process at all. In the absence of this friction, grave
problems with material retention may emerge, which may result in parts that are perhaps
impossible to form at all. Additionally, such a condition may generate a completely different
set of forces acting against the tooling, which may produce such an inner strain within
its material structure that an internal distortion and collapse may become unavoidable.
The only means of controlling friction are lubricants. Lubricating materials are capable of
separating the adjoining surfaces by providing an isolated layer of completely different physical
and mechanical properties between them. With different types of lubricants, different results can be achieved and control of frictional forces may thus be brought to almost perfection.
There are lubricants that are immune to higher temperatures, lubricants that tolerate
extreme pressures, high-viscosity lubricants, low-viscosity lubricants, and other variations.

GstarCAD

GstarCAD is a CAD (Computer Aided Design or Computer Aided Drafting) software platformbased on IntelliCAD technology^[1], using the Open Design Alliance DWG libraries to read and write the DWG file format made popular by the AutoCAD CAD package.

GStarCAD is the innovative alternative to other well known CAD packages on the market, and provides OpenDWG file compatibility, similar environment, as well as an interface which is similar to that of the current market leader in the field.

As with the majority of CAD (computer aided design) software the native file format for GStarCAD is .DWG, which offers full file compatibility with other CAD packages on the market.

There are three versions for different CAD software users: Professional, Standard, and Academic^[2] in English, Spanish, German, French, Chinese Simplified, Chinese Traditional, Czech, Italian, Japanese, Korean, Polish, Russian, Hungarian, etc.^[3]

GstarCAD2012 Tutorial: CAD Sheet to Exce

Conversion among different kinds of digital files is one of our long-cherished dreams due to the reason that it can promote information exchange and improve work efficiency. For designers, converting CAD sheet to excel table is also one of their long-cherished dreams. But can this dream truly be realized?

In GstarCAD2012, the function of CAD Sheet to Excel can convert CAD sheet to Microsoft Office Excel table. Now let’s demonstrate how to achieve this.

First of all, startup the command by clicking Express>Form Tools>CAD Sheet to Excel, the dialog box as below will be displayed. Users can select the table scale that they want to convert from the dialog box. This will decide the size of the table to be generated.


Follow the dialog box to select the sheet that needed to be transferred and press Enter key. GstarCAD will convert the CAD sheet to excel automatically and open it, as the shown picture below.
  
Finally, save the excel sheet. Then the data in the drawing has been successfully exported to excel sheet. We can see the data in generated excel table in accurate format. What’s more, users can revise, add, delete and print the table directly, avoiding the troubles for adjustment.
CAD Table to Excel Table Conversion is one of the new functions of GstarCAD2012. This function aims to offer applicability and usability for users. By eliminating tedious work by hand, this function provides a more convenient way to collect information from drawings (especially old ones) and to generate documents. Users can apply it in variety of schedules, bills of materials (BOM), part list, notes, etc., using the powerful functions found in Excel.

Users are welcomed to visit GstarCAD official website to experience this exciting function.

Wireless attendance management system based on iris recognition

Seifedine Kadry* and Mohamad Smaili
Faculty of Science, Lebanese University, Lebanon.
Accepted 24 May, 2010

Iris recognition verification is one of the most reliable personal identification methods in Biometrics.
With the rapid development of iris recognition verification, a number of its applications have been
proposed until now including time attendance system etc. In this paper, a wireless iris recognition
attendance management system is designed and implemented using Daugman’s algorithm (Daugman,
2003). This system based biometrics and wireless technique solves the problem of spurious attendance
and the trouble of laying the corresponding network. It can make the users’ attendances more easily
and effectively.
Key words: Iris recognition verification, personal identification, biometrics, attendance management, wireless.


INTRODUCTION
While the move towards the digital era is being accelerated every hour, biometrics technologies have begun to affect people’s daily life more and more. Biometrics technologies verify identity through characteristics such as fingerprints, faces, irises, retinal patterns, palm prints, voice, hand-written signatures, and so on. These techniques, which use physical data, are receiving attention as a personal authentication method that is more convenient than conventional methods such as a password or ID cards. Biometric personal authenticcation
uses data taken from measurements. Such data is unique to the individual and remains so throughout one’s
life. This technology has been applied for controlling access to high-security facilities, but it is now being
widespread developed in information systems such as network, e-commerce, and retail applications. In these
technologies, iris recognition becomes the most mature and popular biometrics technology used in automatic
personal identification.

In the beginning, the idea of using iris patterns for personal identification was originally proposed in 1936 by

ophthalmologist Frank Burch. By the 1980's the idea had appeared in James Bond films, but it still remained
science fiction and conjecture. In 1987 two other ophthalmologists, Aran Safir and Leonard Flom, patented
this idea, and in 1989 they asked John Daugman to try to create actual algorithms for iris recognition. But now, this technology is also being used in several other applications such as access control for high security installations, credit card usage verification, and employee identification (Medien and Burghardt, 2002). The reason for the popularity of iris recognition verifying is the uniqueness, stability, permanency and easily taking. Just for this, a number of iris recognition verification approaches have been proposed until now (Zhang and
Jain, 2004; Daugman, 1994). This paper proposes a design and implementation of a wireless iris recognition
attendance management system. This system is an application of the iris recognition verifying and RF wireless
techniques and it is mainly used for employee identification. Through practices, this system is proved to
be easy-to-use and effectively. And this paper is organized as follows: In the first section, we introduce the
attendance management system with different types. Section 2 describes the technological requirements for this system design. Section 3 outlines the functions of this system briefly and describes the hardware and
software design of this system. Section 4 introduces some key problems in the implement of this system and
finally Section 5 contains conclusions and future research plan.

GstarCAD2012 Receives High Praise from Customers

FOR IMMEDIATE RELEASE
(Free-Press-Release.com) January 15, 2012 -- Beijing, China: January 16, 2012-- GstarCAD, leading 2D/3D CAD software provider announces that the newly developed GstarCAD2012 with its powerful functions and good performance as well as cost saving has received high praise from customers.

It is undisputed that whenever there is a new product being launched, customer will be curious and skeptical about it from different aspects. However, the recently released design-oriented GstarCAD2012 with its exclusive features as well as affordable price has proved to the customers worldwide of its high quality and gained extensive recognition.

In fact, GstarCAD2012 now has gone through clients’ test and established a good reputation among them. “The new functions of GstarCAD2012 are amazingly powerful as they are displayed on the videos.” Dave, the customer from America says. When asked where he got to know about GstarCAD2012, he smiled, “My friend introduced it to me.” “I will also introduce this intelligent software to my friends!” He continues. Customers’ keen interest to GstarCAD2012 is also can be noticed from the rising download rate and video views. 

What’s more, GstarCAD2012 changes clients’ perception about design and is favorable for them. Customers from various industries of Architectural, Engineering, Manufacturing and Land Surveying speak highly of GstarCAD2012 and admit that GstarCAD2012 is powerful enough to meet their demands for new design. “Before using GstarCAD2012, I never thought that the design could be done in such a flexible way.” One of customers from Italy says, “It gives me inspiration for design!”

About GstarCAD
GstarCAD is fast, powerful, .dwg-compatible CAD software for the AEC, mechanical, manufacturing, electrical, GIS, survey and mapping industries. The world-class 2D/3D CAD software platform is based on IntelliCAD technology. 

GstarCAD's powerful functions, .dwg compatibility, and programming platform, are built on a cost-effective solution with an easy to user interface. Gstarsoft ensures that your design inspiration comes true. 

Strategies for sustained innovation

The need for constant reinvention is a given in today’s business environment. And while a breakthrough product or concept can catapult an organization ahead of its competitors, in these fast-paced times, that advantage is often short-lived. While major product or service breakthroughs make headlines, it’s the steady incremental innovations made by employees every day that give an organization the sustained growth it needs.

Sustained innovation comes from developing a collective sense of purpose; from unleashing the creativity of people throughout the organization and from teaching them how to recognize unconventional opportunities. As innovative ideas surface, a clear sense of mission empowers front-line employees to act on new ideas that further organization’s purpose.

It starts at the top

Leaders create the psychological environment that fosters sustained innovation at all levels. The challenge is that as an organization grows, management structures and bureaucracies, designed to channel growth, tend to create barriers to small-scale enhancements.

While there are exceptions, in larger organizations employees tend to feel removed from the function of innovation and are less likely to take independent action or offer revolutionary ideas.

The commitment to establishing the right psychological conditions for innovation needs to start at the top. This means that, as a leader, one needs to consider his own assumptions about innovation and his role in creating and changing organization’s culture.

One need to appreciate the value of incremental as well as major innovations, understand the psychology of innovation and take the lead in promoting an innovative culture. Otherwise, it’s just not going to happen. While organization’s innovative capability depends on multiple factors, there are several steps one can take to create the psychological conditions that favor inventive thinking, regardless of industry or the size of organization.

Establish a clear sense of direction

Changing cultures involves changing minds and that takes time. But as with any initiative, a clear sense of the target helps to speed the journey.

Organization’s mission helps to organize and direct the creativity of its people. What is the purpose of consistent innovation in enterprise? Is it to add customer value to existing products and services… to speed delivery… to increase on-time arrivals?

Having a clearly articulated message allows everyone to focus on innovation where it can deliver the greatest value. Innovation, as Peter Drucker has defined it, means creating a new dimension of performance. A sense of mission clarifies the direction of performance and helps determine which new ideas to focus on.

Open communication

Open communication between management and employees sets the stage for an atmosphere of trust. But if one wants to establish a new, more trusting culture, one can’t expect employees to take the first step. 

Company leadership initiates the process of open communication by sharing information with employees on a regular basis. This includes good news and bad news also. 

Southwest Airlines’ policy of sharing information enabled the company to weather the sudden increase in fuel costs during the 1990-91 Gulf War. The company kept everyone informed as fuel prices soared. Southwest’s CEO Herb Kelleher sent a memo to pilots asking for their help. Through inventive thinking, the pilots found ways to rapidly drop fuel consumption without compromising safety or service.

Leaders of organizations that sustain innovation offer multiple opportunities for communication.

While not every company can offer an open-door policy for its senior executives or even a chance for regular face-to-face contact, every organization can institute programs that enable front-line workers to feel heard. From CEO lunches with cross-sections of employees, to monthly division meetings between employees and the general manager, to open intranet forums for idea sharing and feedback, leaders can communicate their openness to hearing innovative ideas from those who are closest to the customer.

Reduce bureaucracy

While larger organizations are often considered less entrepreneurial and inventive than their smaller counterparts, it’s not the size of company that inhibits innovation -- it’s the systems. Bureaucracy slows down action and is a serious impediment to innovation.

Smaller organizations can often move faster on implementing innovative ideas because they have less bureaucracy. When Jack Welch was reengineering General Electric he said, “My goal is to get the small company’s soul and small company’s speed inside our big company.”

Faster implementation encourages further inventive thinking. Think for a minute. If you had an idea for an innovation and it required 6 weeks to clear channels and another 3 weeks to get funding, would you have lost any impetus for further contribution? 

Instill a sense of ownership

An ownership mentality creates a powerful incentive for inventive thinking. When an individual is clearly aware of how his or her interests are aligned with those of the company, he or she has a strong reason to “go the extra mile” to further the mission.

Stock ownership is a significant, if not essential, incentive for employees. However on its own, profit-sharing doesn’t guarantee employees will think like owners. When employees don’t see how their individual efforts affect company profitability, they tend to be passive and reactive. To encourage greater involvement, make sure each employee knows how his or her work affects company performance.

Southwest gave pilots the freedom to design and implement a plan to reduce fuel consumption because they were in the best position to determine what would be effective. Pilots pitched in enthusiastically because they understood the impact their actions had on the bottom-line and ultimately, on their own futures.

Make sure recognition and rewards are consistent

While financial rewards are often tied to innovations, rewarding only the individual or team responsible for the “big idea” or its implementation, sets up a subtle competitive atmosphere that discourages the smaller, less dramatic improvements. 

Even team-based compensation can be counterproductive if teams are set up to compete with each other for rewards. These incentives discourage the cross functional collaboration so critical to maximum performance. 

Companies that successfully foster an innovation culture design rewards that reinforce the culture they want to establish. If organization values integrated solutions, one cannot compensate team leaders based on unit performance. If company values development of new leaders, one cannot base rewards on short-term performance. 

A tolerance for risk and failure

Tolerating a certain degree of failure as a necessary part of growth is an important part of encouraging innovation. Innovation is a risk. Employees won’t take risks unless they understand goals clearly, have a clear but flexible framework in which to operate and understand that failures are recognized as simply steps in the learning process.

Toyota’s Production System transfers quality management and innovation authority to front-line plant workers. Workers are able to make adjustments in their work if they see an opportunity for improvement. If the innovation works, it’s incorporated into operations, if not, it’s chalked up to experience.

A major psychological benefit of Toyota’s method is the development of trust. Employees who trust their bosses are more likely to take intelligent risks that have potential benefit for the company. 

Eliminate projects and processes that don’t work

As organization innovates, one needs to practice what Peter Drucker calls “creative abandonment.” Projects and processes that no longer contribute should be abandoned to make room for new, progressive activities. 

While no organization wants to squander financial resources on unprofitable activities, it is actually the irreplaceable resource of time and employee energy that is wasted if a company holds on to the old way of doing things. 

 

Innovation requires optimism. It’s about an attitude of continually reaching for higher performance. One can’t expect employees to maintain an optimistic attitude if they feel compelled to continue in activities that are going nowhere. 

Excellent quotes from Warren Buffet

 
1. On Earnings - Never depend on single income, make invenstments to create second source 
 
2. On Spending - If you buy things you do not need, soon you will have to sell things you need. 
 
3. On Savings - Do not save what is left after spending but spend what is left after saving. 
 
4. On taking risk - Never test the depth of river with both the feet. 
 
5. On investment - Do not put all eggs in one basket. 
 
and above all  
 
6. On Expectations - Honesty is an expensive gift, Do not expect it from cheap people.

ACTUATOR CONTROL

• Control systems for devices can be described using block diagrams
• Two main approaches to actuator control
1. Torque controlled by current amplifiers driving a motor
2. Speed controlled by voltage using a voltage amplifier
• Torque control maintains a constant desired torque which is desirable in assembly operations.
Also maintains constant force (gripper) without drawing additional power. A disadvantage
occurs when the required torque is less than the applied torque. This causes higher acceleration
and velocities resulting in the non-zero velocity at the target point and inaccuracies. If the inertia
is higher than expected the resisting torque would be larger than the constant applied torque
causing slow motion, and loss of production time.
• Speed control is less affected by variations in inertia and the time to reach the target point is not
affected. The approach is slow and smooth. Problems occur because torque is not controlled.
Motor draws from the voltage amplifier the current required to overcome the disturbance. If
the robot encounters a rigid obstacle the amplifiers fuse could burn-out. This makes it unsuitable
for assembly tasks such as press fitting where a constant force is required, but it is good
for spray painting and seam welding.
• The choice of control depends on the application and the environment
• Inputs to velocity controlled robots from the computer are,
a) A sequence of pulses - each pulse generates one BRU (Basic Resolution Unit). The number of
pulses represents position and the pulse frequency is proportional to velocity
b) a binary word as samples data - used in most modern robots with both velocity-controlled and
torque controlled systems.

DISCRETE CONTROLLER DESIGN

In controller design we try to meet some objective. Typical objectives include,
- positioning - for moving from position to position, where the setpoint is changed suddenly
deadbeat control
first order
- tracking - for following paths where setpoints are constantly changing
first order
- disturbance resistant - unexpected variations can be compensated for
step response
- multi-stage - for complex systems that need small errors
feed forward disturbance - can reduce effects of disturbances
feed forward command - to follow complex motions
cascade - a controller that examines intermediate steps of a process
• typical constraints to be developed are,
- stability - does not diverge over time
- stability - sampling period is short enough (no-aliasing)
- realizable - does not refer to future values

Hydraulic Maintenance

There are two main types of valve designs used
in hydrauic systems. Spool-type and poppet-type.

In a spool design, a spool is positioned in its bore
to connect the various ports in the valve. The most
common type of spool valve we're all familiar with
is the directional control valve.

Because radial clearance is required for the spool to
slide in its bore, this valve design in not leakless.
To say this another way, even when a port in a spool
valve is closed off - a small amount of leakage is
possible and should be expected.

In a poppet design, the valve 'poppet' closes against a seat.
This design is generally considered leakless. That is, if
the valve is closed and the poppet and its seat are in good
condition - there is no leakage across the valve's ports.

BUT there's an important exception to this rule you should
be aware of. Slip-in cartridge valves, also called logic
elements are a type of poppet valve commonly found in todays
hydraulic systems.

Even though a logic element can be configured for flow in two
directions, it is only 'leakless' in one direction.

Even though a logic element can be configured for flow in two
directions, it is only 'leakless' in one direction.

To understand why, read pages 138-139 of
'Industrial Hydraulic Control':
http://www.industrialhydrauliccontrol.com


Yours for better hydraulics knowledge,

Brendan Casey