CUSTOMER:
Leading manufacturer of electrodes

PROBLEM:
Milling tip features on a large variety of different configuration electrodes in very small batch sizes. Set up time is significantly longer than machining time requiring skilled manual adjustment, lowering throughput and increasing costs.

SOLUTION:
Equipment:

• Mazak Vertical Centre Nexus 410A machining centre fitted with Renishaw probing
• Simple designed and manufactured manual fixture, based on a standard manual rotary table for fast set up
• Tooling Selection
• Turnkey application engineering with innovative programming for quick set up.

Installation:
Due to the bent design or shape of the electrodes, the customer had problems in setting up from the datum end and then “finding” the tip end and centreline for accurate machining. The machining processes were performed on manual vertical milling machines.

John Hart proposed the compact and cost effective Mazak VCN-410A vertical machining centre with PC Fusion 640M CNC. In collaboration with our customer we created a design which in turn allowed JHA&R to manufacture a rigid and accurate fixture to suit a vertically mounted manual rotary table.

The fixture was fitted with a self centring vice with one set of jaws and stop suitable for all components. This supported and clamped the pre machined reference end of the electrode. The tip end was supported and clamped by an innovative and flexible adjustable support clamp that was easily moved into position to support the free end close to the machining position. The clamping fixture required only one tool to adjust.

Working with our customer and Sandvik a simplified cutting tool package was specified by our applications staff.

Our application staff then set about preparing a sophisticated macro programming routine that was simple to operate and running within the CNC to calculate the setting angle for the rotary table and the theoretical tip machining point to automatically determine the work position coordinates. The operator only has to input the electrode dimensions and angles from the CAD drawing of the electrode, manually rotate the table and start the program. The theoretical machining point is checked and corrected, within set limits by the Renishaw probe and machining started.

OUTCOMES AND BENEFITS:

• Ease of set up with the macro calculations and easily adjustable fixture
• Very short floor to floor time compared to the old method – savings in the order of 80%
• Better quality finished product resulting from the Mazak VCN-410A machine and fixture rigidity
• More accurate components by improved location method and probe check.

Mazak VCN 410A

Mazak VCN with JHA&R designed and built fixture, Renishaw probe, tooling