cnc articles

The Isel machine is designed for production routing and drilling on a wide variety of materials including wood, plastic, MDF, solid surfacing materials and nonferrous metals

An inexpensive computerised numerical control (CNC) machine has helped start a new production woodworking business. The company produces complicated architectural ornamentation that was up till then mostly made by skilled craftsmen working with power tools. There is a substantial market niche for producing decorative woodcarvings faster, cheaper and at higher levels of accuracy.
Low-cost CNC machines can accurately duplicate a computer aided design program in much less time than someone working by hand.

Although clearly a skilled job, making complicated pieces such as carved mouldings and friezes is a very slow process by hand.

The first piece is typically assigned to a very experienced and highly paid craftsman, who cuts it out with hand and power tools, then less experienced workers typically duplicate the piece using a tracer.

One problem with this approach is that even the most skilled woodworker has difficulty accurately producing three-dimensional contours.

The result is a piece that requires extensive finishing by hand, to chisel and sand the piece the way a customer wants it finished.
The beauty of a CNC machine is that every detail of the piece can be defined to absolute perfection in the CAD/CAM software and allowing time for the operator to do something else while the machine produces the part.

While the CNC machine isn’t perfect, the accuracy of the machines is far beyond what can be achieved by hand.

However, every piece made will be just as good as the first one such that each piece coming off will need little hand finishing
While programming is a labour-intensive process similar to cutting out the first piece by hand, once it is completed other pieces can be produced without constant attention.

All that is required is a person loading raw wood and unloading finished pieces on the machine and occasionally checking to be sure the tool hasn’t worn out or broken.

The result is that architectural ornamentation can be produced at a much more competitive price on CNC machines.

The Isel machine is designed for production routing and drilling on a wide variety of materials including wood, plastic, MDF, solid surfacing materials and nonferrous metals.

It is very flexible and easy to use, and is adaptable to nearly any woodworking problem.

For example, long pieces of moulding can be stacked side by side while the spindle traverses each piece to cut the pattern.

Another piece introduced is called a corbel, a triangular decorative bracket that fits in the corner between a ceiling and wall.

The machine takes a solid block of wood and whittles it down to an intricate 3D design on three sides.

These multisided pieces are mounted on a rotary table that moves the appropriate face towards the spindle one after another.

The Isel machine’s shaft and bearing system produces very smooth, play-free motion and is an extremely rigid system that produces high-quality cuts.

It uses anti-backlash ball screws that have excellent power transmission due to the rolling ball contact between the nut and screws.

This type of contact ensures low friction, low wear and long life.

The ball screws also make it possible to produce wooden parts to the machine resolution of 0.013mm.

Instead of being ball screw-driven, there are less expensive machines using rack and pinion gearing which have too much play to make accurate cuts in small areas.

Also this type of gearing wears out quickly in the dusty environment of a carpentry shop.

The Isel machine uses servomotors to control the cutting motion, while other machines often use stepper motors, which can give a stair-step cutting effect.

With this set-up the company can produce just about anything that customers requires.

One customer asked for a moulding that looks like a grapevine with the grapes protruding in 3D.

From a picture of what was wanted, the image was scanned and then turned into a 3D model.

The artwork is coloured by the use of brushes and flood fill tools and each colour is assigned to an individual 3D profile.

The different types of profiles that can be generated include plane, round and angular.

The parameters of these profiles are controlled by defining the basic shape, start height, limit height and wall angle, giving almost total control over a wide range of 3D effects.

The programme builds 3D reliefs by assigning a height to each pixel in the 2D image.

Then by providing their own artistic interpretation and designing the moulding in such a way that it can be machined quickly, a sample piece in MDF is given to the customer.

From the feedback the programme is modified so that the finished pieces are exactly what is wanted.

Equipped with flexible stock-handling system and integrated automation, a universal production gear hobbing machine cuts gear and gear-shaft type components up to module 4

The EMAG-Koepfer 300 series Gear Hobbing Machine offers a universal concept with highly flexible stock material handling magazines and integrated automation designed to cater for a wide range of gear and gear-shaft type components up to module 4. The outstanding technical attributes of the 300 series, said EMAG to manufacturingtalk.com at EMO 2007, are underpinned by uncomplicated user interface, quick set-up, consistent reliability and high precision, as well as the flexibility to adapt and cater for the smallest and largest production batch sizes.
Gear hobbing gear- and shaft-type components - the gear profiling specialist Jos Koepfer and Soehne, in Furtwangen, Germany, said manufacturing companies are under enormous time and cost pressures.

It makes it absolutely crucial that their production machine concepts should be adaptable to suit their machining requirements.

The K 300 has been specially designed for the machining of a variety of components and batch sizes.

Its application range includes gear-type as well as shaft-type components.

To ensure that these can be produced in small or larger quantities, and to cover just about every conceivable gear cutting task, the Gear Hobbing Machine 300 has a selection of automation systems.
* Nine CNC axes for optimal gear profiles - the Gear Hobbing Machine 300 features nine active CNC axes that accommodate a fully automated machining process.

The company said that only a polymer granite machine base can produce optimum results, which is why Koepfer uses the Mineralit material for its vibration damping properties, said to be eight times better than those of grey cast iron.

Mineralit forms a static, dynamic and thermo-stable foundation for the machine and guarantees an excellent tool life and a superb surface finish.

Other features of the K 300 type include the following.

* The machine is of a closed-loop framework design that offers maximum stability for tailstock and main spindle, even when great clamping pressure and heavy cutting forces are applied.

* Maintenance-free direct drives in all tool and workpiece axes ensure that the gear cutting quality achieved is the best and that it remains so throughout the life of the machine.

* The milling head has been aligned diagonally to the machine base to guarantee easy chip flow during wet and dry machining.

This design allows the chips to fall unhindered into the chip conveyor below.

Two further important points in the development of the machine were easy access and an ergonomically designed machining area.

The latter offers the possibility to mount NC pilot tools such as wheels or turning tools for deburring, vibration dampers, sensors for automatic component orientation, or special applications such as live deburring tools.

* Compact loader with flexible workpiece magazines - the principle of highly flexible magazines and automation equipment that was applied to other Koepfer gear hobbing machines has also been applied and adapted to the K 300.

Close attention has been paid to the different machine and workpiece requirements.

The main feature of the automation is the fast acting Koepfer loading device with V-profile gripper, suitable for workpieces of up to 5kg.

Also available are a variety of magazines for the raw-parts and finish-machined components of different ranges of workpieces.

The capacity of the magazines - and thus the autonomy of the machine - can be increased very easily, and without taking up additional space, by employing various parallel running workpiece feeders.

This ensures the machine can handle small component batches as easily as large quantities of workpieces.

* The control system of the Gear Hobbing Machine K 300 - the control system of the K 300 is equipped with a touch panel and a user interface that closely resembles Windows.

The specially developed, extensive Koepfer dialogue software ensures that complex programs can be generated with ease.

A high specification, low cost CNC 3-axis machine, beginning at under GBP 7,000, can perform routing and engraving, drilling and milling, dosing and sign making, prototyping and modelling

Unimatic Engineers has launched a high specification, low cost EuroMod CNC machine range with starting prices at under GBP 7,000. The EuroMod is a 3-axis, high performance, servomotor driven, CNC machine suitable for a wide range of operations, such as routing and engraving, drilling and milling, dosing and sign making, prototyping and modelling.
Unimatic said it is equally adept at dispensing, laser and water jet cutting, soldering and welding, measuring and verifying, sawing and cutting.

Managing director of Unimatic, Martin Stevens, told manufacturingtalk: ‘What we are offering is a servo driven machine at a stepper price.

Servo machines are quicker, smoother, quieter, and more accurate than ’steppers”.

He said: ‘We are able to combine price and performance because EuroMod machines are manufactured in volumes such that efficiency gains are achieved on all fronts.

EuroMod represents a sea-change in attitudes to CNC machining: it is no longer an exclusive preserve, but the new benchmark for all machining’.
Automation - EuroMod machines are ready to use CNC systems designed to automate a large number of tasks and applications.

Rigid, low vibration steel and aluminium constructions provide the mechanical basis for the EuroMod units.

The 16 x 5mm ballscrew drives are high precision to match the performance of the servomotors.

‘When developing the EuroMod units, the focus was on providing a small footprint,’ said Stevens, ‘Because space saving is a near-universal requirement by virtually all users’.

Any unit need a floor width of only 1160mm.

The XYZ dimensions are 800mm, 1100mm and 1510mm.

The electronics of the EuroMod and the servo motors are optimally matched to the mechanics, the power electronics and the control.

The user gets high power, quiet running and reserves of performance.

The complete electronics of the EuroMod, including an integral PC, are enclosed in a control box.

Operation is through a control panel with keyboard, 10in display and touchscreen.

The EuroMod units are available with or without protective cover.

The versions with cover are equipped with an automatic door opener.

The EuroMod gantry section is fixed and the workpiece is moved below this rigid section.

This design is particularly suitable for precision machine cutting and for multi-axis machining, said Unimatic.

Functional accessories are also available for the EuroMod units.

Options include a work spindle with frequency converter for high speed operations such as drilling and milling, a tool changer for programmable multi-task operations, cooling/spraying device and fume extraction system, vacuum clamping system, CNC joystick and 17in CNC control panel.

During EMO 2007, Gleason introduced a thread wheel grinder for finishing hardened gears and a CNC gear testing machine for production or quality laboratory use

Gleason Corporation’s Genesis 130TWG Threaded Wheel Grinder is a compact, highly-productive machine for finishing hardened spur and helical gears. It uses dressable grinding worms as tools. Three dressing systems are available, as follows. * Dressing with a diamond-plated dressing wheel for maximum productivity.
Dressing with conventional dressing wheels for high flexibility and productivity.

* Optional contour dressing for maximum profile and flank flexibility.

The machine also offers optional patented grinding process for twist-free gearing and a patented grinding process for low-noise surfaces.
A cam-driven high-speed loading system is designed to reduce loading and non-productive time to a minimum.

The Genesis 130TWG also allows the shortest possible changeover times by using quick-change fixtures and other smart detailed equipment.

* Control system - the Genesis 130TWG has the latest Siemens 840D control and user-friendly technology software including process data calculation for easy operation.

The Genesis 130TWG provides the other benefits familiar from the Genesis series , including simple maintenance and a small space requirement.

This equips the machine for all the requirements of modern production environments, said Gleason.

Capacities of the Genesis 130TWG are as follows.

* Nominal workpiece diameter is 150mm.

Nominal module range is 1 - 3mm.

Maximum shaft length is 350mm.

** Versatile 360T Universal Gear Tester: for 90 deg, angular bevel and cylindrical gears - CNC roll testing of just about any gear set type is now possible with the Gleason 360T Universal Gear Tester (patents pending).

It is available in either fixed 90 deg or full angular configurations.

Its ability to quickly perform advanced quality measurements on bevel, angular bevel, and parallel-axis gears makes it ideal for everything from high-production automotive and jobbing to laboratory environments, said Gleason.

It has the following main features.

* Fully automatic SFT and SBN checking of all gear set types.

* Swinging gear head from 65 to 185 deg.

* Compact and ergonomic machine design.

* Tool-less arbour installation and adjustment.

A compact, highly productive machine for the fine finishing of soft spur and helical gears performs plunge as well as diagonal and parallel shaving processes

Gleason described its Genesis 130SVC Shaving Machine as a compact, highly productive machine for the fine finishing of soft spur and helical gears with an outside diameter as large as 150mm. The Genesis 130SVC also has an integrated chamfering and deburring station. The Genesis 130SVC allows plunge as well as diagonal and parallel shaving processes.
Gear flank corrections are made using the Y, X and Z axes and the novel Gleason Spheric shaving software.

As an option, the 130SVC can be equipped for ‘Power Shaving’, a proprietary Gleason process proven in the successful ZS series of Gleason-Hurth shaving machines.

By driving the tool and workpiece spindles the plunge shaving time can be reduced substantially, said Gleason to manufacturingtalk.com.

The 130SV is equipped with an innovative cam-driven double gripper loader fully integrated into the machine.

The Genesis double-gripper loader reduces the load/unload sequence to a minimum.
NC chamfering and deburring station - the 130SVC has an integrated NC chamfering and deburring station to produce a combined machine in the tradition of the Gleason-Hurth ZSE series.

The workpieces are subject to generate deburring before shaving takes place.

Since the process runs in parallel, the floor-to-floor time of the system as a whole is determined by the shaving process and is not prolonged by chamfering and deburring.

The principle of chamfering and deburring is based on the use of a rotary deburring tool, which generates a chamfer on the tooth face edge and removes the protruding burrs on the face side of the gearing with the secondary deburring tools.

The chamfering unit concept means that no manual settings are necessary for retooling.

Different outside diameters or workpiece widths are taken into account by the NC.

Access for tool changes is optimized to ensure the shortest possible changeover times.

A double-gripper gantry loader is used as standard for transferring workpieces between shaving and deburring stations.

As a result, connection to a variety of customers’ automation concepts is possible.

The Genesis 130SV is equipped with the latest Siemens CNC system and Gleason provides Spheric Shaving technology software with process data calculation to help make set-up and operation control easy and intuitive.

Capacities of the Genesis 130SV are as follows.

* Minimum/maximum outside diameter - 10-140 (150) mm.

* Minimum/maximum module (plunge shaving) - 1.0-3.0mm.

* Minimum/maximum module (diagonal/parallel shaving - 1.0-4.0 (5.0) mm.

* Maximum tooth width, plunge shaving - 40mm.

* Maximum shaft length - 350mm.

An improved anti-creeping system that counteracts troublesome cage creep in precision rail guides ensures higher precision, system rigidity and reliability

SKF Linearsysteme has revised its Anti-Creeping-System (ACS), which counteracts troublesome cage creep. The new version ensures higher precision and system rigidity at the same time improving operating characteristics and reliability. The internal geometry of the constraining guide for the cage has been optimised.
The entrainment of the cage elements is provided by an involute gear and a straight tooth gear fit with high vertical coverage.

Also new is the use of corrosion resistant steel.

Since the introduction of the patented ACS, SKF Linearsysteme has been repeatedly asked for precision rails with constraining cage guides.
Larger production batches have not only opened new possibilities in the production logistics, it also led to a new examination of the basic construction of the ACS-Precision Rail Guide.

With the previous construction, there was always a groove between both tracks.

With the new version ACSM, the constraining guide for the cage is directly integrated between both tracks so that there is sufficient room for a reliable module gearing.

In using this development there is no weakening of the track prism and it considerably increases the rigidity in the rail-bearing-rail system.

The involute gear ensures the entrainment of the cage, provides a faultless, clean and low friction run over the complete life cycle of the precision rail.

The present test results in respect of the dynamic values speak for themselves.

These tests showed that over 20 million cycles, with an acceleration of 16G and a maximum speed of 3.2m/s produced no failure or recognisable traces of abrasion.

The tests were carried out with a decentralised mounted mass and a dissimilar preliminarily rail tension.

Without the use of a constraining guide the loading would undoubtedly have led to the cage creeping away from the load zone.

Also new is the use of corrosion resistant steel, which now allows the precision rails to be used in problematical industrial processes such as in vacuum technology, the food industry, the chemical industry and in medical technology.

A belt-driven, compact linear guideway only has to be fitted with a motor to move light loads with high acceleration and speed

R A Rodriguez said that its compact TMT Power-Line linear guideway T100 couldn’t be simpler to assemble. Just fit a motor and the product can then be used to move light loads with high acceleration and speed. The self-supporting structure of the rail and its factory applied M6 mounting holes enable quick, easy and economic installation, said the company.
This belt-driven, four lubricated wheel design can accommodate direct loads of up to 400N and side loads of 1080N.

Maximum stroke from the single piece construction is up to 7000mm.

It is suitable for speeds up to 4.5m/s and typical positioning accuracy is +/-0.1mm.

The concentric bearing arrangement of the design allows easy adjustment of pre-load.

Virtually silent in operation this addition to the R A Rodriguez linear motion range is also maintenance-free.

The motor/geared motor can be mounted directly to the guideway or via a coupling, said the company.

R A Rodriguez told manufacturingtalk that the Power-Line linear guideway T100 is the product of TMT, a company that specialises in the design and manufacture of robust rail profiles for automotive lift-and-carry transfer lines.

Its Speedy Rail system is widely used by the world’s leading car manufacturers.

Plain bearings are designed to meet the highest performance requirements in automotive and industrial applications and offer low wear sliding characteristics and high load carrying capacities

This year, the Schaeffler Group is celebrating the 25th Anniversary of its range of plain bearings, designed to meet the highest performance requirements in automotive and industrial applications. Permaglide plain bearings offer low wear sliding characteristics, high load carrying capacities and heat dissipation properties that are normally associated with metals.
The bearings are maintenance-free and so are ideal for special automotive and general industrial applications.

Permaglide bearings have a porous bronze-sintered structure, applied to a steel or bronze backing, impregnated with the appropriate polymer-mix.

This solid lubricant produces a film between the sliding surfaces, which provides low-noise operation at constant speeds and low coefficients of friction throughout the entire service life of the bearing.

The bearings are a low cost alternative for applications with comparatively low surface loads and where space is restricted.

The bearings are available in the form of bushes, flanged bushes, thrust washers and strips.
Custom-designed versions are also possible, including blanked parts; ball cups; bearing shells; bushes with windows and holes; and bushes with stamped oil grooves.

Bush outside diameters are possible from 3mm up to 305mm (in special cases up to 800mm); strip widths up to 250mm; and wall thicknesses from 0.5mm up to 3.06mm.

Permaglide linear plain bearings (PAB) consist of Permaglide bushes pressed into an outer ring.

The ‘PABO’ design has a segment cut out of the bearing for use with supported shafts.

Alternatively, Permaglide linear plain bearing units PAGH and PAGBA consist of a Permaglide linear plain bearing (PAB or PABO) pressed into a housing.

For the automotive industry, Schaeffler now offers lead-free Permaglide bearings.

Article 4 of the ‘End of Life Vehicle Directive’ stipulates that from July 2008, manufacturers of new vehicles will no longer be permitted to use certain materials (including lead) in car components.

For this reason, Schaeffler offers a lead-free Permaglide P14 and P141 (with zinc-sulphide) bearings.

P14 is designed for dry-running applications, but can also be used in mixed-friction and hydrodynamic applications.

These plain bearings have a running-in layer made from PTFE and zinc sulphide, plus a sliding layer comprising a porous bronze layer filled with PTFE, on a steel backing with a very thin protective layer of tin.

P141 is similar in structure to P14 but is intended for oil-lubricated applications, although the bearings can also be used dry.

The running-in layer this time consists of PTFE and zinc sulphide with special wear-inhibiting additives.

Said to be ideal for utility and crane applications, sealed plastic ignition switches are constructed of durable, engineering grade plastics and sealed to IP-67

Leading manufacturer of heavy-duty electrical and electronic products for the vehicle industry, Cole Hersee Company, has introduced sealed plastics ignition switches. Cole Hersee said that the switches are constructed of durable, engineering grade plastics and are ideal for utility and crane applications.
Cole Hersee’s fully-sealed plastics ignition switches are available in a variety of configurations to meet all customers’ needs, including anti-restart.

The switches have an integral Deutsch connector, and the contacts are sealed to IP-67.

Available with or without a key boot, Cole Hersee’s plastics ignition switches are rated at 10A at 12V DC, 5A at 24V DC and are tested to SAE J259 for ignition switches.

* About Cole Hersee - since its founding in 1924, Cole Hersee has been a pioneer and leader in the development of heavy-duty electrical products for the vehicle industry and has earned a reputation for quality and value.

Cole Hersee collaborated on many basic industry standards and today is a preferred supplier of over 2,000 dependable vehicle products and accessories.

Cole Hersee products are available as standard or custom designed products to meet customer needs.

Carbon/graphite Babbit impregnated bearing materials are designed to operate in difficult environments up to 350 deg F, where conventional lubricating methods cannot be used

A manufacturer of oil-free, self-lubricating materials, Metallized Carbon Corporation, offers Metcar grades M-161 and M-162 mechanical materials for running at elevated temperatures. These novel carbon/graphite Babbit impregnated materials are designed to operate in difficult environments where conventional lubricating methods cannot be used.
This proprietary Babbit impregnation provides excellent wear resistance and enhanced lubrication for bearings and thrust washers for submerged and dry environments.

Operating at temperatures up to 350 deg F these materials are unrivaled for lubricating in submerged low viscosity fluids such as water and fuels.

For dry environments they provide excellent oil-free lubrication at high temperatures.

These Metcar grades are typically used for moderate loads at medium and high speeds.

Designed to provide maximum lubrication, bearings manufactured from these materials are low in friction and will not score the mating shaft.

* High compressive strength - bearings manufactured from Metcar materials are self-lubricating, non-galling, dimensionally stable and have high compressive strength.

Boasting excellent lubricating qualities and long life, these materials are completely homogenous and provide continuous lubrication for their service life, making them an excellent candidate for bearings, bearing assemblies and mechanical components for operating at elevated temperatures.

* About Metallized Carbon Corporation - since its inception in 1945, Metallized Carbon Corporation has been manufacturing high-quality, dependable bearing solutions for severe service environments.

With over 60 years of application engineering experience, Metallized Carbon offers the field expertise and data necessary to provide the solid choice for lubrication in a wide variety of industries, supplying completely machined components as well as materials for customer machining.

Metallized Carbon is ISO certified and produces the Metcar brand of solid, oil-free, self-lubricating materials.