Imsa specifies NSK products for deep-hole drilling tasks

Italian manufacturer Imsa has specified NSK products on its specialised machining centres for deep-hold drilling. The machines are particularly popular for mould-making applications in the automotive industry. The moulds used for the manufacture of medium and large-sized plastic components require deep-hole drilling to create long and precise cooling ducts, some measuring up to 1500 mm and beyond.

Deep-hole drilling is a complex machining operation due to the absolute precision and productivity required, particularly (but not exclusively) in the automotive mould-making industry. Over more than 30 years of activity, Imsa has introduced numerous technical innovations, providing its customers with new concepts capable of making a quantum leap in the performance and productivity of deep-hole drilling.

These include its exclusive autofocus system for the optimal movement of steady rests developed as far back as 1996, and the concept of independent axes for drilling and milling, which arrived the following year. In 2000, Imsa unveiled a vertical gantry structure for the column that provides 16 times more rigidity than traditional solutions.

One of Imsa’s most recent innovations has been the development of a rotary-tilting table, which allows the machining of moulds in five axes using just one clamping position, further reducing manufacturing time. MF1000-3T EVO, a deep-hole drilling machine for small to medium automotive moulds up to 2.5 tonnes in weight, is the first model to be equipped with this solution.

Marco Colombo, head of technical department at Imsa, explains: “For this specific application we created a single-head machine with one HSK63A electro-spindle [200 Nm], combined with three deep-hole drilling heads featuring automatic head change and an 80-position automatic tool changer. In addition, the MF1000-3T EVO is supported by an automation system of our own design for the two-station pallet changer [expandable to six], which allows the customer to carry out complete machining operations of considerable complexity with minimum downtime and long unmanned cycles.”

Imsa is using NSK’s latest-generation solutions to achieve the very high performance required, even in a relatively small machine. “To transform axial movement into rotary movement, we use two 63 mm diameter NSK ZSS series ground ball screws,” says Colombo. “Compared with the ball screws of previous generations, they guarantee greater rigidity and perform better in terms of speed and load capacity. As a result, the machine's working axes can move at feed rates of up to 30 m/min. This is just one of many examples of how the components we choose in collaboration with NSK’s technical specialists enable us to achieve our ambitious targets."

Another NSK product family that is extremely important for Imsa-designed machines is RA series roller guides, which represent the ultimate in rigidity, load capacity and precision. Their ‘caged roller’ construction technology ensures smooth and silent running, and prevents the rollers from crossing to totally eliminate the risk of damage or premature failure. The roller guides, together with NSK ball screws, are the heart of a solution that guarantees rigid movement in Imsa’s machines.

Colombo concludes: “A well-dimensioned ball screw from NSK is practically eternal, so we’re delighted to continue this successful partnership. In addition, we appreciate the company’s ability to be very flexible; local NSK staff are always available to meet our particular needs at short notice. We often order bespoke products, such as custom-length or twin ball screws, which are essential to ensure the best mechanical performance of our gantry structure. We particularly appreciate flexibility in delivery.”