«Our company was founded in Brescia in 1995 and since then we have been in the contract business,” explains Nicola Bertelli, owner of MB Meccanica. “Initially we had traditional lathes and milling machines. Then, in 1999, we purchased our first machining center. The next year we transferred to Botticino (BS) to our current location, and at the same time we expanded our machine fleet adding other machining centers.
In 2006 we purchased our first Hurco machining center and the optimum yield of this system convinced us to continue to invest in this manucturer’s solutions. We now have six machining centers and a lathe, all manufactured by Hurco». One of the main characteristics of the systems installed at the company in Brescia is flexibility. It could not be otherwise, given the variety of fields of application in which MB Meccanica works.
The main sector of activity is in the food industry: machinery for flexographic printing (or hot label printing) as well as presses. Thereafter come the sub-contracting of components for trucks, sock production machinery, medical components, and motorcycle components.
In addition to the above-mentioned work, the company develops automated solutions for the food industry in a special metal working shop.
MB Meccanica’s resources allow working with about 15 customers per month, for whom the company processes prototypes or small lots. «To meet the needs of so many customers for such completely different industries, it is essential to be able to write machine programs quickly and, above all, without error», continues Bertelli. «This aspect represents one of our strong points.
Over the years we have written more than 6,800 programs,which are constantly updated based on new machining technology introduced to the market, like, for example, new tools which allow using different machining parameters. Furthermore, each month we write new programs
according to the specifications highlighted by the customer, thus gaining greater experience in this field.»
The level of flexibility achieved by MB Meccanica is partly due to the fact that all of the machines are networked: via a computer station, all of the programs can be transferred to the machining centers, accelerating the changeover from one lot to the next; secondly, it is due to the ease of programming and use of the Hurco solutions. The decision to work with a uniform machine fleet is linked precisely to the programming flexibility of the machines. The programs can be modified quickly and the man/machine interface makes the use of the numerical control simple, even for less expert operators. Furthermore, thanks to the architecture based on industrial PCs, software and hardware are continuously updated: this guarantees that the systems are always at the highest level of efficiency and functionality.
Hurco machines have in fact been designed to allow easy update. Proof of this is the Windows-based operating system for the numerical control, which ensures a continuous evolution of the machining center software. Another strong point of the Hurco solutions is the ability to simulate machining on a virtual machine, so that
an error-free program can be uploaded on the machining center. Simulation reproduces any movement with great fidelity, starting from tool change to air gap, obviously including the actual machining.
«When choosing what machines to pay, we payed particular attention to the potential of the numerical control because from a mechanical point of view, we didn’t have any special performance requirements», adds Bertelli. «The cycle time for the parts we machine is significantly less than the programmed times, because we process small and very different lots, so everyday we must write several programs. This is why we recently purchased the VMX24i and VMX42ti models, which give priority to flexibility and reliability over dynamic thrust».
This choice was also made in favour of the operator, who in this manner can control the trajectories of the moving parts and intervene if there are incorrect movements or potential collisions. Basically, this is an additional level of safety which adds up to the already cited machining simulation software and which results in less waste per part produced and therefore in lower costs for the end customer.
The WinMax numerical control is one of the strengths of VMX24i and VMX42ti, together with the high precision and repeatability of the machining. The latter characteristics are due to the mechanical solidity and the sturdy cast iron structure of the machines, which grant them the stiffness (both static and dynamic) necessary to ensure precise machining and an extended machine life. The base is made from high quality cast iron and, as are all the structural parts, has been designed with the support of finite element calculation. It is supported by dedicated platforms equipped with alignment devices that allow rapid and effective levelling. Finally, the guides with recirculating ball-bearing pads allow the moving of the carriage (Y-axis), which is also equipped with guides with recirculating ball-bearing pads for the sliding of the table (X-axis).
The table was designed with the aim of attaining maximum geometric stability, even under high loads. In detail, the VMX24i model (610x508x610 mm working range) has a 760×508 mm table with a maximum load capacity of 900 kg, while the VMX42ti model, being larger (1067x610x610 mm working range), is equipped with a 1270×610 mm table with a 1200 kg load capacity. Finally, the upright is fixed to the base and is a cast iron piece as the carriage and the table. It is equipped with recirculating ball-bearing pads for sliding the spindle head (Z-axis). To guarantee maximum machining precision, the seat in the head that holds the milling spindle has a temperature maintenance system, which is supported by a chiller unit located outside the machine housing.
Both machines are served by a carousel tool magazine with 24 spaces. All of the tools are held by tool holders, which are automatically oriented to promote the picking and placing operations by the exchanger arm. “We are very happy with both the machines and the relationship we have developed with Hurco over the years” concludes Bertelli. “We can easily and quickly write new programs, which allows us to gain experience every day. The reliability and precision of the Hurco machines are a fundamental part of our workshop to meet the needs of even the most demanding customers.”
Interview published in the magazine Tecnologie Meccaniche of September 2014 by DBInformation