In the last eight years, the Cumbernauld-based sub-contract machining specialist Cowie Engineering has doubled its annual turnover, increased its head-count from 13 to 24 and acquired (in 2013) an adjacent factory unit, doubling its total floor area to 9,500ft².

During that time, the number of vertical machining centres (VMCs) on the shopfloor, all of which are from Hurco, has also doubled — to 10.

The latest Hurco is a VMX60SRTi five-axis VMC with swivelling spindle head and flush rotary table — a design that provides ‘the optimum working volume for the single-set-up machining of larger parts for the oil and gas industry’.

Supplied by High Wycombe-based Hurco Europe Ltd (www.hurco.co.uk), this machine is also allowing the sub-contractor to win extra contracts from the motor-sport sector, particularly for the production of high-tolerance components ‘in one hit’ from materials ranging from stainless steels (and other steels) to aluminium and plastics.

The use of linear scales rather than encoders for positional feedback from the linear axes, together with Renishaw part probing and tool-length setting, provides the high levels of precision demanded for the construction of racing cars.

The tolerances held are from typically ±0.05mm, although tolerances of 8 or 9µm total are often required.

Such ‘tight’ tolerances have necessitated the installation of a new co-ordinate measuring machine (an Aberlink ‘Axiom too’) in a temperature-controlled room, along with a recently appointed full-time inspector, to verify that F1 components coming off all the Hurcos and other machine tools are ‘compliant’.

Before the VMX60SRTi, the most recent VMC additions (in 2018) were two of Hurco’s latest-generation VM10i machining centres — one fitted with a fourth axis.

These were preceded (in 2016) by a VMX42t and a VM2, both with Hurco fourth-axis rotary tables.

The other equipment in use includes eight lathes (one of them is a Hurco lathe with a 10in chuck that has been on-site since 2011) and a Sodick CNC wire-cut EDM machine.

A family affair

Ross and Grant Cowie — sons of company founder Rodger — together with Rodger’s wife Cathie and his daughter Julie (who recently qualified as a chartered accountant), work full-time in the business.

It was established in 1999, and all the machining was initially carried out on manual mills and a lathe.

Less than two years later, the company installed its first CNC machine — a second-hand Hurco BMC25 with a 1,050 x 500mm table that allowed larger and more-complex components to be produced.

Cowie Engineering has standardised on this make of VMC ever since due to the reliability of that early model, “together with the speed and user-friendliness of the conversational control”.

This control system was originally Hurco’s Ultimax, now called WinMAX.

Director Ross Cowie said: “This control was — and still is — ideal for producing the small batches we require, which generally range from one-off to 50-off.”

Other Hurcos at Cowie Engineering include a BMC4020 with a 1,220 x 510mm table (installed in 2004), a VMX64 with an even larger table and a fourth axis (2009), two smaller VM1 models installed shortly afterwards, and a VMX30 (this was bought in 2011 and replaced the original VMC).

The type of work undertaken by ISO 9001-accredited Cowie Engineering has changed over time.

Its early contracts were mainly for mining, defence, construction and bottling applications, as well as food and switchgear; and while business from the latter two sectors remains prominent, there is an increasing focus on motor-sport, the electrical industry in general and — increasingly — oil and gas, which Ross Cowie says appears to be emerging strongly from a marked and sustained downturn.

CAD/CAM programming

Also new in the last couple of years has been the installation of an off-line CAD/CAM system from OneCNC.

Previously, all programs for the VMCs were created at the Ultimax/WinMAX controls using touch-screen conversational menus, sometimes with direct input of DXF data to describe more complex geometry.

Now, with the introduction of this CAD/CAM package, sections of ISO blocks can be extracted and inserted anywhere within a conversationally created cycle any number of times, allowing the stitching together of a complete part program using the NC Merge feature within WinMAX.

This facility considerably advances Cowie Engineering’s programming capability.

Other useful features within the latest version of the Windows-based WinMAX software that are used by the sub-contractor include: Mill Polygon, which facilitates milling a multi-sided contour with equal-length sides; and Mill Slot, which creates a slot defined by a line or an arc segment and a width, the slot ends being round or square.

The Swept Surface function built into the control is also frequently used; this allows a 2-D surface to be moved along a contour to create smooth 3-D geometries within one ‘conversational data block’.

Ross Cowie added: “We have historically machined a lot of stainless steel, particularly for the food industry, and the material still accounts for around a fifth of our throughput.

“More recently, new contracts have introduced a diverse range of engineering steels, as well as challenging alloys such as Duplex, Inconel and titanium; we are also machining a greater variety of aluminiums and plastics.

“We regularly use our Hurco fourth-axis tables to gain access to parts for machining on multiple sides, hopefully in one hit.

“We position them individually with or without a tailstock, or alternatively mount multiple parts on a trunnion for indexing.

“Sometimes, we machine components requiring full simultaneous four-axis cycles.

“We have established a reputation for a quick turnround and high-quality work.

“Our third trainee since 2011 has started his apprenticeship, and the first two are firmly established members of staff, helping to assuage a lack of skilled operators in Scotland.”