Back in the early nineties we were approached by engineers from Piano Forte Supplies Ltd (PSL Ltd) whom were widely recognised as industry leaders in producing world-class bright ware components for the automotive industry and whose headquarters was in Roade Northamptonshire.
However, this particular bright ware pressing, namely the Rolls Royce Grille header, was proving to be extremely troublesome in terms of keeping the shape of the part, maintaining a highly polished finish and holding quite exacting dimensional tolerances.
PSL had tried other laser cutting companies with very limited success, as those companies either damaged the highly polished surface or could not maintain the dimensional tolerances. This resulted in a lot of costly rework for PSL.
The challenge set to Subcon was to maintain a 0.5mm tolerance whilst not only protecting the highly polished surface but keeping the shape of the pressing during the laser cutting process.
Anyone familiar with working on deep drawn pressings will fully understand the issues faced when trying to obtain a given shape from a deep drawn pressing, further compounded in this case by the fact that the material used was stainless steel. The stresses within the pressing will cause the part to “ping” and distort when the laser cutting process starts to release the object part.
In this case we had to design and manufacture a fixture that would keep the shape of the part without damaging the all-important highly polished surface, whilst maintaining a high degree of accuracy during the 3D laser cutting process.
In order to achieve this high quality finish we created a fixture using a high strength resin, moulded to the shape of the Grille header which was attached to spring loaded clamps. The moulded fixture was then slightly trimmed back to enable our unique 3D cutting head to access the cutting area at the base of the pressing.
By using this method, not only did we not damage the surface we also maintained a 0.5mm tolerance hence saving our customer a substantial amount of time and money in not having to rework any of the parts.
As Purchasing Manager at Piano Forte Supplies we had to overcome many challenging and difficult scenarios, especially when trying to find solutions for producing low to medium volume sub assembly complex products from high value deep drawn stainless steel pressings.
Because the cost of tooling would have been prohibitive, we would always involve Subcon Laser. From the early nineties to PSL’s closure a few years ago, Subcon were without doubt our preferred supplier as their laser cutting knowledge proved invaluable on numerous projects, especially when three-dimensional cutting was required.
Kevin Betts, Ex Purchase Manager PSL Ltd.