Water-jet cutting comes naturally to the ROIbot

The TM Robotics' BA series of Toshiba Machine robots, known as the ROIbot, uses a modular building block design, allowing single or multiple axis configurations.

Among a variety of applications, this makes the ROIbot ideal for operating a water-jet cutter, particularly in the textiles and plastics industries, as well as in the aerospace industry, machine shops, die-casting, metal stamping and food preparation.

The system can be used for normal cutting, using standard tap water, or abrasive cutting, using water mixed with solid particles. The properties of the cut can be adversely affected by changes in cutting distance or the speed of cutting and, as a result, the ROIbot provides very accurate acceleration and deceleration, as well as consistent speed of movement and excellent repeatability.

Indeed, controlled acceleration is the biggest issue that has to be addressed, particularly in abrasive cutting. The more precise the cut needed, the more efficient the acceleration must be. This is because the abrasive jet is a 'floppy tool', and is prone to wander during machining. On straight-line cutting, this translates into a 'lag' in the cut. This 'lag' isn't a serious issue when cutting in a straight line, but becomes critical when the cut approaches or exits a corner. As the jet approaches a corner, the motion must be accurately slowed down, in order that the bottom of the jet can catch up to the top, and remain perpendicular to the material. If this can't be achieved the result will be an inaccurate cut.

To counter this, the ROIbot can be used in conjunction with the Toshiba SR7000 controller, which has a 'smooth' function facility which allows the corners to be completed without concern for lagging. The smooth function also finds use in sealing and gluing, where it controls the precise application of adhesive. This eliminates the non-uniform 'dumping' of glue which results in eliminating unattractive blobs along a seam or in corners. This is vital in the manufacturing of domestic goods where appearance is paramount.

Up to four controllers can be connected together in a multitasking system and each one can accept a pulse-train input for movement commands, allowing an external motion control system to be easily integrated. As an option, the unit can be supplied with the TPH-2A teach pendant, which connects to a main controller and serves as an alternative programming device. It also provides the controller with home position; start, stop, reset and emergency stop instructions. It can display alarm conditions, current program step and current position data.

Further options include clean room and dust resistant versions as well as regenerative discharge units.