Racking up productivity gains
Air Bearings found the ideal solution to catching and storing high value parts being manufactured on a Mazak 250MS turning centre by introducing a Rota Rack parts catcher from Hydrafeed.
As a subsidiary of global electronics group Hitachi, Dorset based Air Bearings manufactures high speed drilling spindles for its parent company in Japan. The spindles that work at between 80,000 to 350,000revs/min in specialised drilling machines for PCB manufacture are high value added components that demand high accuracy and surface finish. To meet the need for increased productivity the company has introduced four Mazak turning centres in the last two years to add to its 10 Mazaks already on site that all use Hydrafeed barfeeding equipment.
The acquisitions have seen the company increase its ability to manufacture parts in one-hit, something that has become a necessity for the company that has won three Queens Awards for Industry in the last ten years, one for innovation and two for export. With the increase in productivity Air Bearings found a bottleneck with the high value components coming off the machine as Manufacturing Manager Gary Waldron explains: ‘We have one operator running two Mazak 250MS machines and the operator has to manually remove each component from the part catcher before the next part falls in the bin and hits the previous part. Aesthetics and surface finish are critical to our parts and any marks could lead to re-working or scrap. The aluminium main drill bodies and leaded bronze bearing modules are soft materials, which makes marking easier than on most materials. We searched the marketplace for over a year and not found a suitable solution until now.’
The challenge was to first find a solution that would not damage the parts, and working with Mazak the company resolved the matter of taking completed parts from the machine sub-spindle onto a short conveyor. However, the latter was incapable of storing any quantity of parts for any period of time and this forced an operator to be present at all times. ‘An operator had to physically start the cycle for each part despite the capability of the machines to run batches’ explains Waldron. This bottleneck was addressed by the parts catcher from Hydrafeed.
The parts have an average cycle time of six minutes. The company works a two shift system, and there is downtime of over five hours between shifts as well as at break times and at any other time an operator cannot be present. The introduction of the first Rota Rack installed in the UK has been a revelation, says Waldron: ‘Since installing the Rota Rack in March we have been able to run the turning centre unmanned. We can now store parts on the Rota Rack with the confidence that they will not be damaged. The Rota Rack is lined with a soft plastic that guarantees the parts will not be marked and this is essential to our production. In the few weeks since installation we have witnessed a massive change. The initial installation and bedding-in period of any machine isn’t a period where benefits are generally realised. However, in this situation the Rota Rack has made an immediate impact on our business and we have doubled our production almost instantly.’
The aluminium parts range from 50 to 75mm diameter and 12mm long; whilst the bronze parts are 20 to 25mm diameter with a length of 25mm. The parts are manufactured in continuous batches of 300 to 500 and the parts catcher comfortably accommodates the needs of the company. ‘We are apprehensive of letting too many parts collect in the Rota Rack as even the slightest component contact could cause damage but despite this apprehension we can produce and store over 100 bronze parts and 15 aluminium parts without intervention in the Rota Rack. With an average 6 minute manufacturing cycle time the Rota Rack comfortably covers any periods where the machine is unmanned.
Waldron concludes ‘Previously the machine operator spent his working day moving from one machine to the next continually starting the cycle with any time in between cycles being spent inspecting parts and setting the machines. Now the operator has more time available for alternate tasks on the shop floor. Looking to the future, the Rota Rack has made a significant impact on our business and we will now look at implementing the system on a further two or three Mazak turning centres in the future. This could potentially enable our operator to run more than two machines. Regardless of machine capabilities we had a bottleneck caused by the human element, which is no longer the case and our turning centre no longer has to take a break with the staff.’
