Gear-quality project at Norbar Torque Tools

When Banbury-based Norbar Torque Tools conducted a gear-quality project at its Banbury plant, the company chose a Stark Zero Point system from Roemheld UK Ltd (www.roemheld.co.uk) to achieve the desired improvements in quality and repeatability, while also reducing set-up times.

Norbar had bought two new Gleason machines and was looking to reduce unproductive time through all aspects of the gear-shaping process. The company had used Roemheld zero-point mounting technology before, so was aware of its capabilities. After consulting with Roemheld, Norbar purchased Stark zero-point mounting plates for both machines; and to increase accuracy while reducing loading times, the new machines use automatic drawbar clamping.

All fixtures were then fitted with the Stark zero-point nipples, allowing fixturing to fit straight onto the base plate without adjustment. Norbar also introduced a colour-code system on the Stark zero-point bases, allowing fixtures to be mounted with an accuracy of 10-15µm and a repeatability within 5µm.

Norbar also reduced the downtime for first-off quality checks by introducing as much in-process checking as possible. This allowed the company to produce almost four-times as many components than with the previous set-up.

Tim Bloor, the design engineer at Norbar UK who headed up the project, said: “My aim was to minimise set-up times. It is still early days, but we have seen a big improvement in gear quality and consistency, much shorter run times and greatly reduced set-up times. The expenditure will be well worth it in the long term.”