Magnetic workholding for 5-axis machining

The Tecnomagnete range of Italian-made, permanent-electromagnetic workholding systems introduced to the UK last year by sole agent, 1st Machine Tool Accessories, includes the compact MillTEC Grip magnetic clamping system for 5-axis and five-sided metalcutting applications.

Such machining strategies reduce the number of set-ups, often to one, shortening floor to floor times. Excellent access to the component also allows the use of shorter tools, enabling increased feed rates, heavier cuts and hence higher productivity.

Low-profile, frameless MillTEC Grip clamps have a double magnetic circuit that allows uniform clamping between the workpiece and the magnetic surface and at the same time between the magnetic system and the machine table.

A patented feature is the sealed construction with a monolithic, uniform, all-metal top section into which an array of magnets is embedded for holding down workpieces. There are no inserts, sealing resin or any filling compound, so the electric circuitry and magnets inside are protected from contaminants, leading to long, trouble-free life.

MillTEC eliminates bending and deformation that can be caused by mechanical clamping, ensuring stability and structural uniformity of the whole assembly. It leaves five sides of a component freely accessible for milling and drilling and the light weight of the clamping system means that heavier components can be processed for a given maximum table load.

The electrical supply is connected for only a few seconds to activate and then deactivate clamping of the workpiece, which during machining is gripped by the power of the high energy permanent magnets. The system avoids the drawback of conventional mechanical workholding, whereby machining is restricted by the need for clamps to secure the workpiece. For the same reason, the cost of such clamps, other consumables and fixtures is eliminated.

Parts can be clamped onto the magnetic plate in a matter of seconds, speeding set-ups. Some other conventional clamping systems need components to be pre-machined and naturally this time is saved as well with Tecnomagnete products.

A further advantage is the thinness of the MillTEC Grip magnetic plate, either 42mm or 51mm, which maximises Z-axis travel on a vertical machining centre or Y-axis travel on a horizontal machine, allowing taller components to be manufactured.

For added versatility, the workpiece can be raised from the working surface by a steel block carrying the MillTEC module. In such cases, it is possible to address machining around the periphery of the sixth side if the component overhangs the plate. It also gives more clearance for the spindle and tool to facilitate machining of the four adjacent sides.

Flexibility is further extended by the option to use reference dowel pins. These may be employed for accurate, repeatable, offline fixturing of components on pallets used in multi-pallet machining cells. They also enable fixturing of non-magnetic components such as aluminium, brass and composite, as well as any awkwardly shaped part, in conventional fixtures.

1st MTA www.1mta.com