To expand its aerospace sub contracting machining services, Avionic Components has invested GBP390,000 in a 6m long-bed CME travelling column CNC bed mill.
Long-bed mill ups subcontractor's capabilities To expand its aerospace sub contracting machining services, Avionic Components has invested GBP390,000 in a 6m long-bed CME travelling column CNC bed milling facility. The facility gives Avionic to machine complex 2m3 workpieces on a 'pendelum' basis or the longer structural ribs and members. Avionic has consistently followed a planned growth pattern in terms of the size and complexity, explained Manufacturing Manager, Derek Dehany.

'We began business machining components up to 250mm3 and now we have a minimum capability of 2m3 and are also able to machine the longer structural ribs.

We acquired the CME CNC bed mill to take on larger and more complex work.

Much of our machining is in the more 'exotic' stainless steels, nickel- and magnesium-based alloys.' Within a week or two of commissioning, Avionic won a contract to machine rear mounting ring forgings for a leading aircraft turbine engine OEM.

The length of the CME long bed allowed Avionic to set up the four or five different operations in a progression from one end to the other.

'There are four and five set types of this engine mounting ring,' said Derek Delany.

'We were able to process batches of rings through the fixtures, with the machine working almost continuously.' The engine mounting rings are ring forgings in titanium alloy.

Each is 1.5m OD and contain recesses and different patterns of slots, holes and profiled location surfaces.

The raw forgings have a section of approximately 110mm wide by 95mm deep.

Standard machined features include four sets of parallel slots on the ID, of 29mm width and about 20mm deep contained in a profiled projection about 100mm wide and 250mm long.

The rings are progressed through four or five fixtures on the CME bed mill's bed.

Each ring requires about 16h of rough milling and 8h of finishing on the OD.

The slots have to be rough- and finish-milled, so the total machining time exceeds 30h.

Verification of location areas and positioning of the fixtures and post-process inspection is carried out using a Renishaw MP7 touch-contact probe.

A typical roughing operation would use a 125mm face mill at 120 rev/min and feed of 50mm/min taking a 10mm depth of cut.

Avionic uses the OOptimill1 feature in the machine1s CNC which maintains a constant cutting load on the spindle and adjusts the feedrate to suit different depths of cut.

'Optimill has certainly extended the life of the tips,' commented the operator.

'It is a good, sturdy machine and can take big roughing cuts, which is what we needed it for.' Derek Delany added that the CME bed mill is not an expensive machine in relation to its size.

Avionic Components.

Avionic Components is one of a family of a dynamic group of companies belonging to Hampson Aerospace (Hampson Industries plc) and working primarily in the Aerospace and Defence industries.

The company is an approved supplier to Rolls Royce, Garnett Turbine Engine Company, BMW-Rolls Royce and BAe and Airbus Manufacturing.

Components manufactures include air inlets/ducts, compressor casings, split bearing casings, housings, safety critical rotatives, structural ribs, engine mounting rings, seal rings and VIGV rings.

Materials machined include cast irons, Waspalloy, Nimonics, Titanium and its alloys and magnesium.

Machining capacity now ranges up to 6000mm by 1500mm by 2000mm with a maximum part weight of 4 tonnes.

Avionic Components also carries out advanced adhesive bonding techniques and complex mechanical assembly and testing.