"Our state-of-the-art clamping system ensures that the cutting inserts are always absolutely flush and won't shift," states Peter Heinemann, head of engineering at Swiss Tool Systems. The two new boring heads (called micro heads) being presented by the Swiss precision manufacturer at this year's EMO are extremely slender, with outer diameters of 25 and 32 mm. This extends the range of applications, even for work pieces with critical interfering contours. The micro heads, designed for speeds of up to 30,000 rpm, can be fitted with cutting inserts for a boring range of 0.3-19.1 mm.
Innovative clamping solution for ultimate precision
The cutting inserts are tapered at the bottom. This is part of the innovative clamping system developed by the Swiss company. As a counter piece, a similarly tapered cylindrical bar ensures that the cutting inserts are flush in the clamp. The tapering on both components guarantees the greatest possible face contact and this ensures that the cutting attachments can be clamped absolutely tightly and with utmost precision. As a result, they remain safely in place even when pressure is applied to the insert. Subsequently, the top of the cutting edge is always aligned precisely with the centre. The shank diameters for the attachments are four and seven millimetres.
The cutting inserts available for this kind of high-precision boring come separately and fall into narrow categories according to the specific application. Swiss Tools offers six cutting inserts that are 4 mm in diameter and three bits with 7 mm shank diameter for speeds of up to 30,000 rpm. "We broke down the adjustment ranges into narrow yet practical increments of one millimetre to give users the highest possible precision for their manufacturing," states Heinemann. Starting at a boring diameter of 6.9 mm, users can work with reversible carbide cutting inserts. This makes tool use more flexible and minimises costs.
The system allows for cutting inserts provided by other manufacturers for conventional clamping systems, albeit with reduced precision. For example, for shaft diameters of ten and sixteen millimetres, boring heads can be clamped with a collet chuck. These heads have an internal coolant supply. "Interfaces are planned for other connection types," states Christian Wagner, head of sales. Speeds of up to 50,000 rpm are also currently being tested. The micro heads are already balanced on delivery using an innovative engineering concept, and they do an outstanding job in use, with practically zero imbalance."
Micro tools for micro production
Settings can be made down to a diameter accuracy of 0.002 mm with a nonius. A single Allen key can be used to adjust all settings, as well as for clamping, releasing, setting the diameter and exchanging the cutting insert. The coated scale screw offers clearly legible scaling. The production of these micro tools reflects Swiss precision manufacturing that is on par with the manufacturing in other industries such as watch-making, medical technologies and IT.