Norbar Torque Tools has invested over £300,000 in a new Gleason-Pfauter CNC gear hobbing machine with robotic feeder in a bid to match demand for increased sales.

The production of professional gears involves a slow process and set up time can take up to an hour and a half. “It was time to move on in terms of production speed, accuracy, consistency and design flexibility,” explains Tim Bloor, Design Engineer at Norbar Torque Tools.

The new hobbing machine will produce around 70% of Norbar’s gears. Where it would have previously taken 15-20 minutes to cut a set of three gears, Norbar has just completed trials where a single gear can be cut in about one minute and 20 seconds. Set up times have also been slashed and, with experience, could come down to as little as 15 minutes.

Norbar also decided to invest in an automatic robotic feed magazine, so rather than having a load time of 20-30 seconds, this is now achieved in just five seconds.

Having a shorter set up time also means that the company does not need to build up large stocks. Whereas in the past it would have made enough gears to last a month for example, it can now bring this down to a week’s worth of stock.

It also gives the company the ability to cut more complex gears than just spur gears. With the gear hobbing machine Norbar can add intricate details such as crowning to gears, or a slight helical taper. “When a gear is heavily loaded, it will twist,” Bloor elaborates. “You can therefore build a negative twist into the gear, so that when it is fully loaded, it will be straight. Gear hobbing gives us the flexibility to look at these techniques for future products.”