The latest series of Y-axis sub-spindle Doosan Puma 2600SY turning centres is now being offered by Leamington Spa-based Mills CNC Ltd.

The new machines are equipped with a 10in chuck and feature an 81mm-diameter bar capacity. They are also supplied with built-in spindles (as opposed to belt-driven spindles), which generate less vibration during cutting operations.

Further innovations include six strategically positioned heat sensors that automatically monitor — and compensate for — any thermal displacement occurring during machining operations.

In addition, the spindles feature a reconfigured bearing structure (this comprises two angular-contact bearings and two taper-roller bearings) to improve C-axis positioning accuracy and spindle run-out (now less than 6µm).

The Puma 2600SY Mk II uses a high-performance coating from NTN (as opposed to Turcite) on its box guideway axes — a move that is said to result in improved and more responsive movement, as well as reduced wear.

Other performance improvements include: an improved design of milling turret that incorporates a ‘Curvic coupling piston structure’ and boosts the clamping force by 12%; improved durability of the Y-axis carriageway; and a spindle air-purge function that helps to prevent chip and coolant ingress.

The machine will be exhibited for the first time in the UK at Mills CNC’s Open House, taking place on 18-19 October (www.millscnc.co.uk).