The CNC vendor NUM launched an innovative pan-and-tilt tool head for plasma, laser, and waterjet cutting machinery applications. Called NUMcut, it is a simple way to extend the capability of machinery from 2D to 3D applications, with precise multi-axis interpolation.
The tool head design delivers the versatility of movement and stiffness required for precise cutting motion. No cables are used to move the low mass head. Gimbals and the Cardan universal joint convert the movement of two linear actuators into 360 degrees of panning motion plus control of tilt angle up to 47 degrees. Combined with the conventional three-axis X-Y-Z movement of the underlying cutting machine, this approach is a simple way to migrate machinery to three-dimensional performance.
The NUMcut weighs only 30 kg; about a third that of some 3D toolhead structures used today. The yoke element ensures that stiffness is not compromised, virtually eliminating backlash. Only the cutting tool itself is subject to the panning and tilting movement, thereby avoiding any need for cable runs to motors, or encoders that are then forced to flex and twist with the tool head’s motion.
A simpler and smaller version of the tool head offering control of tilt angle up to 8 degrees is also available to allow machine builders to compensate for the taper of plasma or waterjet beams. This variant is considerably smaller, allowing multiple tools to be mounted if required.
The Cardan-based mechanics give the toolhead several advantages compared with current alternative motion control approaches – such as motion control systems with motors and gears mounted on the moving head, or complex mechanical arrangements such as parallelogram frames.
NUMcut is offered as a complete turnkey system for machine builders, for either 2.5- or 3D tool head control: each version of the tool head is supplied with all the supporting hardware and software required: servomotors and drives, and the Flexium CNC kernel including the drivers that transform 3D path tracing motion into interpolated motion control commands for the two linear axes. The package allows simple programming in the typical style of a five-axis machine – with three linear and two rotational axes of movement. As the tilt angle is limited by mechanics to a maximum of 47 degrees in all directions, operator safety is assured and any need for additional protection measures are minimized.
The tool head’s low weight and compact form factor makes it easy for a machine builder to convert an existing simple three-axis cutter into a five-axis machine. Alternatively, it becomes simple to design one new machine platform that can be assembled in three- or five-axis variants.
Filed Under: Machine tool industry + subtractive manufacturing, Motion control • motor controls