PROJECT CASE STUDY

GMC

ELX Valve Body

Hydraulic System Aluminum Casting

Gujarat Metal Cast (GMC) is a foundry specializing in lost foam aluminum casting based out of Gujarat, India.

Rollamo Engineering has been machining a variety of castings for GMC for more than 20 years. In 2007, Rollamo worked on a critical aluminum casting called ELX valve body, a hydraulic system part for its end customer Wabtec Corporation in USA.

MOLDING

PLC-SYNCHRONIZED LOST FOAM TOOLING

The ELX valve body required a massive lost foam mold measuring 1m x 1m x 1m. The casting featured overlapping slide cores on all four sides, synchronized via PLC to manage 108 intricate features without core collision.

1m x 1m x 1m

Large-format lost foam mold size

108 FEATURES

Complex casting geometry and ports

PLC SLIDE CORES

Synchronized slide movement on 4 sides

MACHINING

84 OPERATIONS ACROSS 12 FIXTURE SETUPS

Critical machining of the ELX valve body involved 84 distinct operations from all 6 sides across 12 setups. Rollamo developed dedicated fixtures in-house to hold a cumulative tolerance of 0.1 mm between setups.

84 OPERATIONS

Machined from all 6 sides

12 SETUPS

Custom multi-axis fixture sequence

0.1 mm

Tolerance maintained between setups

QUALITY & PROCESS INNOVATION

MICRON-LEVEL METROLOGY & TURNING PROCESS

The engineering team transitioned the critical taper bore process from vertical milling to CNC turning, achieving a +10 micron tolerance and 7 micron surface profile.

3-POINT AIR GAUGE

Special on-line inspection system developed for continuous part quality

HEIGHT MASTER PROBE

Custom probe engineered to measure and control groove depth in microns

RESULTS

SIGNIFICANT REDUCTION IN NON-CONFORMANCE

The process change from vertical milling to CNC turning significantly reduced component non-conformance from 10–12% to 0.25%, demonstrating the effectiveness of Rollamo's engineering and process innovation.

BEFORE

10-12%

Non-conformance

→

AFTER

0.25%

Non-conformance