Guides take new CNC concept to reliable conclusion

A THK product story

Edited by the Engineeringtalk editorial team Sep 11, 2003

To design a low-maintenance vertical CNC machine capable of cutting structured polycarbonate with a knife blade, Polycut undertook an iintensive research programme to source the finest components.

To design a low-maintenance vertical CNC cutting machine capable of cutting structured polycarbonate with a knife blade, Hull based Polycut (a trading division of Clearview (Yorkshire)) undertook an intensive research programme to source the finest possible components.

The cornerstone of the innovative flatbed technology is THK's SSR linear guides featuring Caged Ball technology.

Launching a new product is certainly a challenge.

It involves long hours, painstaking research and a steep learning curve to fully understand all the new production issues and component parts.

For Yorkshire-based Polycut, the launch of its first-ever CNC cutting machine was a massive undertaking.

"The idea was to produce a low maintenance machine, which meant considering every component individually to ensure that it was suitable and would give us a reasonable life expectancy", says Rob Carmichael, one of the directors at Polycut.

"It involved a lot of work as we had no previous knowledge of these components".

Launched last year, the Polycut Machine relies on THK's SSR linear guides to transport the system's cutting head around the 7 x 2.4m vacuum-suction cutting area.

However, rather than cutting the structured polycarbonate sheets with a conventional circular saw, the ingenious vertical flatbed system slices through the structured polycarbonates with a heavy-duty precision blade, thereby generating virtually no swarf.

Attached to two perpendicular aluminium beams, the machine's cutting head traverses the vacuum bed at a maximum linear speed of 2m/s.

Each beam contains a single SSR15 guide to provide accurate linear movements and is transported horizontally by two further SSR20 linear guides positioned along the machine's top and bottom parallel structure.

Controlled by an integrated PLC and running pre-programmed CNC software, the Polycut machine is designed to be reliable, efficient and cost effective.

"THK's linear guides are massively important because the machine is based on motion control and relies on the accurate positioning of the blade on the sheet", Carmichael explains.

Reliability is clearly an important factor, not only in determining the success of the new triple-axis cutting machine, but also in defining Polycut's new reputation as an OEM.

"We're aiming to establish a reputation for selling a value-for-money product that is also reliable", Carmichael states.

"The idea that THK's linear guides, specified for the Polycut machine, typically have an operating life in excess of 10,000km without maintenance was a great attraction".

The SSR's dependability is derived from its Caged Ball design, which ensures that the linear guide's balls are equally spaced and are able to retain lubricating grease between them.

With a variable cutting speed and a maximum cut depth of 40mm, the Polycut machine is perfect for cutting structured polycarbonate sheets into panels for use as glazing in conservatory roofs or green houses.

THK's Caged Ball linear guides ensure that the machine's maintenance requirements are kept to an absolute minimum and the cutting head retains its positional accuracy.

Carmichael explains: "This is the first cutting machine that we've built and sold commercially, so we had to get it right.

In deciding to produce the Polycut machine we recognised that there is a sizeable market for a value for money knife cutting machine, which takes up a minimum of factory space.

During the last 12 months the demand has confirmed our initial views.

In not compromising on the quality of components used, the teething problems encountered have been kept to a minimum, particularly with respect to THK components.

THK came highly recommended and that gave us a lot of confidence.

At the end of the day, we have a reliable, low maintenance component supplied by a renowned manufacturer".