The recent installation of what is Holt Broadcast Services’ third machine, an XYZ 500 LR vertical machining centre supplied by Devon-based XYZ Machine Tools, is already paying dividends, with improved cycle times, reduced post-machining operations and greater versatility.

Founded in 1994, Holt is a specialist manufacturer of sheet metal enclosures, whether they are standard 19in rack mounting enclosures common in the broadcast industry or custom designed solutions. Its customers range from broadcast services through the electronics and aerospace sectors.

While much of the company’s production can be generated using conventional sheet metal forming equipment and skills, there is also a requirement from machining. This is generated through and extensive use of extruded material and the individual requirements of customers, where the design and manufacture of specialist tooling, such as punches, makes machining much more cost-effective and efficient.

Holt initially purchased a two-axis ProtoTRAK mill from XYZ Machine Tools for this work, then progressed to a three-axis ProtoTRAK bed mill for greater efficiency. The XYZ 500LR vertical machining centre has again transformed how this work is undertaken.

Jon Sturgess, workshop manager, said: “Typical of this work are vent panels, which can have up to 400 holes in them. We normally produce these in batches of 100-off and by utilising the toolchange and 12,000rev/min spindle of the XYZ 500LR, we are cutting cycle time per panel by up to 30min, whcih results in a significant saving.”

Further benefits of machining these parts compared to punching include the elimination of secondary operations. Moreover, punching caused distortion that required correction as well as burring on both sides. With machining, distortion is eliminated and, deburring is reduced to just one side as holes are deburred as part of the machining process and included in the cycle time saving.

Holt Broadcast Services found the switch from the XYZ ProtoTrak control to the Siemens 828D control was also straightforward, with setter/operator Chris Trinder quickly getting up to speed with the Shopmill conversational programming following initial training provided by XYZ.

Mr Sturgess concluded: “We certainly have no regrets in the switch to the XYZ 500LR. We are slowly building up the number of jobs we do on it and when these repeat it is a simple task to just set the X/Y/Z datum and away we go. This, and the addition of the carousel toolchange and increased spindle speed, is where we will see the greatest benefits as we move forward.”