Perforated straight tooth rack

Helical tooth rack

Officine Meccaniche Zanatta is specialised in the production of precision components and particular racks for industrial applications. These are accessories that convert a circular movement into a straight or curvilinear one, depending on the main profile and can be made both straight and in the form of helical tooth racks.

The different shaping results in different performances, in particular concerning the mode of release of the bit, i.e. the gear wheel. These racks can be used both as active elements, on the side of the engine block or the piston, and passive in the transmission chain, depending on the type of use.

The main difference between a straight profile, where all the teeth are made up of parallel segments with a certain degree of depth and bevel, and the helical one lies in the progressive transmission of the force.

Precision helical tooth rack

All our processes are carried out starting from full blocks of steel with a square profile, or flat depending on the type of application and the dimensioning of the individual teeth is made according to the criterion of maximum resistance, that is, the duration against stress is preferred as the primary parameter.

This is linked to the hardness of the material, to the surface treatment that can be done in the form of post-cut annealing, i.e. realignment of the clivial planes and reduction of the surface breaks of the lattice, in the case of alloys, but also if it is homogeneous steel.

Subsequently, finishing machining is carried out exclusively with a CNC machine with direct control over the piece being made with digital instruments for the control of sample consistency and which allows the oscillations in height and width of the individual teeth to be homogenised.

This is necessary to allow your machines to transmit the force with a constant start without suffering tearing effects, which could endanger large structures and cause the very dangerous phenomenon of non-linear oscillations, i.e. vibrations that make gates and moving planes tremble, especially in the case of old installations.

Helical profile racks guarantee an exceptional seal if they are coupled with gears designed specifically for this type of application, with a force transmission capacity and consequently an absolute optimisation of the consumption peak on the engine.

The management of the current absorption linked to the starting point is necessary, otherwise, it translates, in the case of a project not carried out in a workmanlike manner, into sudden and not budgeted blocking phenomena, with a much higher frequency than the ordinary one.

Machining of multi-module helical racks

From a technical and engineering point of view, we can produce for your different types of helical tooth racks, with quality ranging from 6 to 10 and different additional machining with high alignment machines such as drilling and milling.

Concerning materials, the applicability of a mechanical accessory is closely linked to the starting alloy. There are applications where it may be necessary to use plastic, for example in the case of devices that have the first need for lightness and that transmit a limited amount of force in the starting phase, up to steel.

In our catalogue, you can discover all the advantages of alloys such as C45, AISI304, AISI303, 18NiCrMo5, and 39NiCrMo3, among the main ones, but we are also available for other metals on request, as well as for nylon.

We work for you from selected raw materials that are supplied to us through a privileged chain and that include different types of steel from simple to alloy, with different titrations, suitable for corrosive environments or with certain risk factors, up to stainless steel with various grades.

The selection of our materials was made based on experience gained directly in the field by all our technicians in charge, both the engineers in the design studio and the workers involved in the use of CNC machines.

We have taken care to choose materials with high modulus for you, to guarantee a level of fineness of the processing and above all the curvatures of the teeth, thus reducing negative factors such as noise and unwanted oscillations.

These, in particular in the case of installations with support not completely supportive, for example, if it is a case of fixing the rack of a gate to the ground in cement or brick, limit the risk that screws and bolts can be damaged or detached over time.

All-in-factory processing

Our project flow naturally starts from the data you provide us, which can be a sketch, in the case of applications that require this specific type of simplifying approach, up to the complete CAD file.

For you, we provide not only the formalisation and production of the single piece but also the verification of the actual characteristics requested by you, a fundamental factor to avoid an investment that can become a problem.

If there is an incompatibility between the solution requested by you and the physically feasible one, in the workshop we will promptly communicate our vision to your technicians and provide all the necessary advice to align any deficiencies or difficulties in the management of the material during the design phase.

All our technicians, from the design department to the administrators of CNC machines have received high-level training specific to their role, but they are also required for an interdisciplinary relationship that we need to grow as a company for the production of precision helical tooth racks.

Working in watertight compartments is the worst possible strategy for a manufacturer of mechanical components because the absence of the right degree of feedback promptly translates into problems in the implementation phase.

This is why we are always at the forefront if there is a need to create a relationship of trust and communication between the individual layers of production. Our workshop is at your complete disposal for every correction and modification to the project.
Above all, we have evolved to guarantee you thanks to an all-in-factory strategy of being able to establish with great precision the timing and methods of the machining, whether it is to create a single helical rack element, for example for a gate to be updated or for a prototype, or whether the work concerns large batches.

We operate with a production speed in line with your business strategies for maximum satisfaction, in the range of modules ranging from 0.5 to 30.

Everything is obtained from the top-quality steel surface, or die-cast in the case of specific applications, both with nylon and diecast alloys. On each batch or piece, depending on the type of intervention, we carry out all the necessary tests regarding the quality of the helical profile alignments, the curves and above all the degree of hardness and surface quality.

The CNC machines at our disposal, with many degrees of freedom, allow us to produce extremely fine details for you, concerning the lateral planes of the helical toothed racks and their elements, thus allowing a perfect matching with any component.

In addition, we can produce elements of length for a maximum of 6 continuous metres per single rack, thus reducing the unpleasant phenomenon of poor coupling alignment.
Obviously, since these are high-precision works, we provide not only for the production but also for the milling up to 0.03 mm/m concerning the lateral inclination and the prevention of torsional phenomena.

We always check that our processes, which are carried out strictly at low temperatures using synthetic-based lubricants for tungsten carbide tools, do not cause deformations, in particular when the thickness of the material removed is significant compared to that of the original starting steel bar or nylon block from which a helical tooth rack was obtained.

Precision mechanics for your helical tooth racks

For your precision mechanics work and for the realisation of your high-reliability components, contact our representatives. All the office technicians are at your complete disposal for any kind of in-depth analysis.

Rely on our accurate and reliable cost estimates, both for small batches and for large runs with regard to the production of helical toothed racks and other elements, from the fittings to the gears.

We offer exclusively top-quality materials and a process with all the verification tests, necessary to ensure that your piece has the ideal behaviour possible, minimising vibrations, cracks and twists, but guaranteeing an excellent force transmission under every application hypothesis.

We also provide excellence in the case of assembly in environments that are aggressive from a chemical or physical point of view, for example, for areas with hard suspended particulates, for which there is a need for hot surface treatments and annealing, such as to make the abutment surface of our racks absolutely indestructible.

Rack with milled teeth: for efficient and performing machines

When we talk about a rack with milled teeth, we refer to a device combined with a toothed wheel that aims to obtain a continuous linear motion from an originally rotating motion.

It is a major component in many mechanical productions: as we shall see, the scope of application of the racks with milled teeth embraces the industrial machinery sector, with particular regard to precision with high stresses, plasma cutting and waterjet In the automotive industry, the racks with milled teeth are used for steering systems.

Some companies also use them for the transfer of non-fixed bridges.
The difference between the racks with milled teeth and the cylindrical gears lies in the maximum force that can be applied to the tooth and this is because no twisting movement is applied to this transmission element. The most important element of the rack is represented by the milled teeth that allow them to be used in one area rather than the other.

These adjustments follow the same rules applied to the gears to become finished profiles or pre-milling that incardinate them in specific categories.
The machining of this rack involves an initial step of creating the teeth made with a type of cutters similar to creators, but without the continuous thread towards the external diameter, to pass, to the heat treatment and then move to the phase of milling the teeth. There are, for example, cutters capable of cutting two teeth at a time with high speed: these are tools with a considerable diameter that in some cases can reach up to 200 millimetres.

Their length also varies according to the power and capacity of the module of the teething and milling machine, to obtain optimal milling both from the point of view of precision and the finished product’s quality.

Compared to the past, today the racks with milled teeth are used in many sectors of the industry and that is why they are of different sizes, as well as the modules, differentiated according to the levels of precision that are intended to be obtained.

Modules: a variety of sizes

Thanks to the wide use of racks with milled teeth, the available modules can be catalogued according to the width. Among the most performing racks that are on the market today, you can find modules that reach even over 90 millimetres, with the ability to transmit force levels of thousands of Newtons.

For an approximate list, we could say that racks with milled teeth are used:

• to make automatic loaders or other commonly used machine tools;
• certain types of steering gear mounted on cars;
• production of high-precision measuring devices, such as medical devices or numerical control machines also used in hospitals;
• some machinery used in the graphic and textile sectors.

Due to the wide use that is made of these racks today and thanks to the wide range available on the market, it is possible to obtain unlimited lengths by assembling racks with different lengths.

The machining of this type of rack takes place in consecutive steps: the milling cutter plays the role of cutting a certain number of teeth and then moves along the axial axis of the rack for a precise value that must correspond to the number of steps inserted into the milling cutter. After the milling phase, we proceed to cut another series of teeth and the subsequent milling, giving life to a proper production chain.

In the production process, the movement must take place extremely precisely; this can only happen using numerical control.

Types of racks with milled teeth: straight teeth or helical teeth

Racks with milled teeth can come in two types: straight teeth or helical teeth, these are different production methods that do not involve any change in the precise profile of the cutter. The latter is always positioned in the section of the normal teeth, reaching the purpose for which it was designed.

When the helical rack is moved along the axis, following the milling of a group of teeth, the distance of the displacement will correspond to the number of steps of the milling cutter that concern the normal section divided by the cosine belonging to the angle of the helix.

A problem that often occurs during the production of racks with milled teeth is their deformation due to heat treatment. The high temperatures cause a twist, or a curvature, called a bend, which assumes different values and damages depending on the rack’s length. To avoid this problem, high precision is required to carry out modification operations with super metals suitable for the milling to be carried out.

The case of short racks or those that require limited levels of precision is different: in these cases, the teeth are ground directly with milling. To understand the machining technique, it is necessary to consider that rack cutters with milled teeth are not equipped with a standardised profile, which is defined by the pressure angle and the module.

For this reason, it is very common that the same milling cutter is necessary to produce different racks with different precision characteristics and variable lengths.

New technologies in the field of racks with milled teeth: innovation and high automation

In the different production phases to which the rack is subjected, the different rack teeth may have to be milled, which requires different treatments such as a finished profile for one and pre-milled teeth for the other: in these cases, the high automation and the cutting-edge machinery manage to obtain the same pressure angle, the same module and two different types of milling. This is a truly remarkable result that has only been possible for a few years thanks to the advances that technology has made in the field of production systems.

Many rack manufacturers consider it necessary to reduce the number of types of cutters to be stored in the warehouse, for this reason, they make requests to the primary manufacturers to build a single finished profile able to penetrate more, performing the tooth milling in an increased way.

Only in this way it is possible to reduce the processing phases, optimising the processing times to obtain a perfectly executed product, without defects and usable immediately without further modifications.

Rack with custom-milled teeth: precision and customisation

Racks with milled teeth are the classic elements used to transmit the translational movements and mechanical rotation between the different parts of the machines and motorcycles. This factor explains the enormous diffusion they have had in recent years and the increase in commercially available types.

The main concern of industrialists who need tooth milling is to find products made with the highest quality material to last a long time and able to maintain very high safety standards. But not only that, the needs of modern industry are much more complex than in the past and require precision, resistance and perfect finish to be ready for use without the need for further treatments. It is not possible to offer generic products of average quality but racks of different sizes to meet the most diverse needs of the industries.

Aware of these needs, Officine Meccaniche Zanatta is a reference point for the design, production and sale of racks with milled teeth throughout Italy: it offers a wide range of racks suitable for various needs, as well as standard series combined gears, all characterised by a very high-quality level. Each gear is made of carbon steel standardised in modular sizes according to DN 3962/63/67 to ensure a complete connection at the base of the tooth with a significant increase in flexion and resistance.
The systematic use of this new generation of Numerically Controlled Teething. Machines ensures custom tooth milling, which meets the precision standards required by DIN 3962.

By visiting www.officinemeccanichezanatta.com you can find a wide range of models suitable for the most diverse needs, with different adjustments to ensure maximum quality, precision and durability over the years.

What exactly is a rack

A rack is a gear with a linear shape, placed horizontally on a plane or as a rod, which serves to transform a rotary motion into a linear one and vice versa. It consists of a toothed structure with a variable shape, which can be straight or helical teeth, with a perforated structure or not depending on the needs.

These essential elements allow the operation of numerous machineries, such as sliding gates, and apply in all kinds of industrial sectors.

Therefore, relying on a good manufacturer such as Officine Meccaniche Zanatta allows you to obtain a product made to perfection, since even a centesimal error in the construction of the rack could determine the incorrect operation of the entire machinery.

To better understand the operation of this rack, we can indicate it as a coupling of toothed wheels, one of which is based on an infinite radius, flowing one over the other by translating the rotational movement in linear or the opposite.
The teeth usually have the shape of a trapezium and fit perfectly to promote a more fluid work development.

What are design racks

The modern industry offers a wide range of standard racks, equipped with milled or helical teeth, which however sometimes do not respond exactly to the needs of the client. This is why, using special precision machinery, it is possible to create customised racks, that is, designed to meet the needs of the particular gear, making the mechanism suitable for its function.

What are the parameters to consider when creating a design rack?

• The shape: the first aspect to take into account is the structure that the rack will have, to be selected according to its use and the machinery where it will be inserted.
  The teeth can therefore take on the most disparate connotations if you have the right equipment to make them, to be used in every sector of the industry since it can be said that no sector does not need such technology.
• The material: usually hard-wearing and easily malleable tempered steel is used during processing to make the custom-made racks so that they can last for a long time and always maintain their initial shape without changing during use. The material in question can be simpler or made of an alloy, depending on the resistance it must have linked to the type of machinery it will compose. In some cases, it is decided instead to opt for plastic die-casting, especially if the stress that the machinery will have to endure is not such as to require the use of steel.
• The dimensions: being a design rack a detail that finds application in practically every industrial sector, the request is very varied from the point of view of size.  Officine Meccaniche Zanatta handles designing and fine-tuning types of all kinds, both in the single piece and in the wider supply, to meet the specific needs of the customer and create a product that is perfectly functional to its final destination.  Using a standard gear rather than one created to measure could in the long run affect the fluidity of the work and make it decidedly more difficult over time.
• Resistance: depending on the industrial sector where the rack will be inserted, it must be made to withstand more or less continuous stresses. There are in fact machines where their function is simply to move the rotary motion in linear and vice versa, others where this involves a weight lifting or a greater performance of the product from the point of view of resistance. In general, the racks of the Officine Meccaniche Zanatta are all designed to last a long time and comply with their function without losing precision.
• Accuracy: some machines operate exclusively with precision racks, which need to be calibrated to the penny to be really effective. For this reason, relying on experts in the field means obtaining exactly the piece that you have requested, so that the work flows easily and the appliance does not freeze due to an incorrect calculation on the components.
• Quality: the racks are classified according to a parameter that is called quality, which determines the degree of precision. Officine Meccaniche Zanatta only uses a selection that ranges from 10 to 6, giving its customers a finished product to perfection, able to ensure excellent performance over the years.  Whether it is a large order, or instead only one element is necessary, you will get a rack of superior quality compared to competitors in the sector.

How is a design rack made?

To create a rack designed to perfectly meet the needs of the customer, it is necessary to have the most modern instrumentation in circulation, which allows you to obtain a precise result and be responsive to the project.

Officine Meccaniche Zanatta therefore use CNC magnetic table gears, the best currently on the market, which allows you to vary the shape of the tooth repeating it on the entire line identical and perfect in every part.

At the end of this first phase, the CNC straighteners and milling machines come into play CNC, which rectify the position of the tooth and verify that the rack is identical in all points and can slide in a completely linear way on the machinery.

The straightness tolerance is allowed up to a maximum of 0.1 mm/m, thus leaving a much smaller margin of error than many other competitors in the sector.
The brand philosophy is based on maximum precision, to fully satisfy the customer both in the request for a single piece and a larger supply.

The operation is completed with milling and drilling, with a limit of L=5000, so that it is possible to carry out personalised work depending on the type of machinery that will later be composed. Thanks to the appropriate instrumentation, Officine Meccaniche Zanatta also reach a quality 6, the best possible, especially if the rack will be composed of a precision apparatus.

The quality control will finally be carried out by a three-dimensional machine, which revises the rack to design in every facet, verifying that the structure of the tooth repeats itself constantly and has the required shape, practically without possible anomalies even of very small dimensions.

In what scope are design racks used

As anticipated, there are really many industrial sectors that require companies such as Officine Meccaniche Zanatta to create customised racks to design, asking for the development of an ad hoc project for their needs.

It starts for example from the sector related to the processing of wood, plastic, glass or aluminium, which uses different machinery equipped with this technology and which requires silent components, with straight, milled or perforated teeth.
Also useful are the racks for portal machines, where a linear action is required that remains constant and continuous over time.

The version with helical teeth, on the other hand, lends itself more to lifting axes, where a discrete resistance is required and therefore you opt for a tempered steel, simple or composed of an alloy.

Alternatively, a further field of application is that of manipulators, which benefit from the particular shape of the teeth, as well as the latest generation of welding robots.
If you take a close look around you, you will find almost every machine a rack, sometimes selected among the standard solutions but much more often in a customised design.

Based on the quality required, then, automation systems can be treated more or less technologically, especially with low repetitiveness and precision.

How to request a consultation at Officine Meccaniche Zanatta

If you are looking for a serious company that deals with the production of customised design racks for your needs, the suggestion is to go to the studio and request a consultancy without commitment.

After having illustrated your needs and the types of machinery you use, an accurate design will be carried out that will allow you to devise the perfect model of a rack.
Based on the quantity, an accurate quote will then be drawn up, which includes all expenditure items to have a precise idea of what the final costs will be.

All the details will be established here, including the type of teeth, the quality that the product must comply with, the level of precision and the type of material that will be used, depending on the level of resistance to be achieved.

Each parameter is studied in detail by an expert in the field, forged by years of experience in the field and continuously updated through courses and in-depth information about the latest news in the sector regarding the machinery and techniques to be used.

You will be in hand to a team of professionals who will be able to first design and then create perfect custom-made racks, at very competitive prices in the face of an optimal quality that can last a long time.