Grinder cuts lead-times for diesel specialist

Investment in a new Jones & Shipman Ultramat Easy external cylindrical grinding machine by Leicestershire specialist engineers O.L.D Engineering has not only given the company additional capacity but also has improved productivity with considerably reduced set-up times.

O.L.D is a Tier 1 supplier of both components and sub-assemblies for large diesel engines – typically found in construction plant, locomotives, marine applications and large vehicles.

Batches sizes are low – approaching 100 is rare – but the need for flexibility in finish grinding any one of over 400 different components highlighted the attraction of the Ultramat’s Easy grinding and dressing programming software.

The O.L.D grinding section in Hinckley has, until the arrival of the Ultramat, comprised three CNC grinders and supporting manual machines. By their nature these were not quick set-up machines and as continuous improvement manager Chris Topp explains, increasingly short lead-times and flexible call offs by customers required a faster response.

“Additional capacity was the initial driver for considering a new machine but when the capability of the software became evident, we soon realised the additional benefits in terms of very short set-up times,” he explains.

“The machine’s highly experienced CNC operator also embraced the technology and benefits and he now looks after two machines in the cell. Not untypically, for one customer alone we could be producing up to 100 different format components in highly variable batch sizes a week which illustrates the importance of eliminating non-productive time between machining.”

Having loaded in the 400 plus grinding programmes, O.L.D has achieved simple and rapid set-ups for automatic cycles but should it be necessary, there is an easily convertible manual override.

O.L.D has specified the Ultramat Easy with a 1m grinding length capacity to cover all of its likely shaft length options with the machine featuring a one piece ‘Tee Bed’ design with a fully supported table combined with technical innovation and the ability to offer high geometric accuracy.

Incorporating a touchscreen used to access the fast to set J&S ‘Easy’ software, the control panels have membrane-type touch keys and electronic handwheels while the machine also has automatic dressing and grinding cycles which means it can be quickly set, then left unmanned. As standard it is equipped with Heidenhain Absolute Nano linear scales and Fanuc Digital AC servo motors and control.

There is a high proportion of shaft work with heat treated bearing surfaces ground to ±4µm without in process diameter gauging required. Typically the grinding of a shaft can involve five different diameters, shoulders and under cuts in a single cycle. The (optional) Marposs wheel head mounted shoulder location touch trigger probe is vital to ensure component positioning is precise in the Z-axis, in relation to the master datum of each component type.

Batches of components are gauged manually during the grinding cycle but after completion are subjected to individual high accuracy inspection on a Tesa Scan 52 which offers colour coded classification of the measurement values and enables the analysis of the results at a glance.

Finally, the dressing cycles performed by the software include in cycle/out of cycle, dressing with full compensation including dress on demand and easy form dressing. There are also straight, facing, angle and ISO wheel dressing macros.

“Since its installation in June 2015 the Ultramat has rapidly integrated into an invaluable part of our operations and has given us an immediate payback in reduced downtime alone,” Mr Topp concludes. “We have the capacity now to offer a subcontract grinding service with the combination of our operator skills complemented by the Easy software creating a competitive combination,” he adds.

O.L.D. ENGINEERING http://oldengineering.co.uk

JONES & SHIPMAN www.jonesshipman.com