Production and packaging systems supplier, Sewtec Automation has dramatically increased machining output by adding five new HAAS machine tools with Renishaw touch probes and a new system of shift work.
Bernard Meehan, Managing Director explains that the company did 140 hours of machining each week on six CNC machine tools in 2009. By July 2010, the capacity was increased to 1180 hours per week with 11 CNC machines.
The capacity increase was achieved via a substantial investment in HAAS vertical machining centres supplied with the HAAS WIPS system (wireless intuitive probe system).
According to Mr Meehan, Sewtec equipment is being installed across the world at international companies expanding into developing markets and who seek world-class standards of quality and reliability in their regional factories. Sewtec decided to change their approach to producing the machined parts for their equipment based on the increased demand and a change in the nature of the orders.
Jerry Elsy, Production Manager at Sewtec who played an instrumental role in the change says that their customers come to them for the quality of the finished machinery. While local machining subcontractors have served them well for many years in machining the parts, the business growth has compelled Sewtec to get most of their CNC machining done in-house to keep costs low.
Design for manufacture and value engineering
With the knowledge that the parts they design will mainly be manufactured in-house, Sewtec engineers can match the capabilities of their machines to how part features are specified.
An important element of this is value engineering, a systematic method of maintaining the basic function of the part but reducing the costs by taking different approaches to manufacture. Design reviews are critical to controlling this process.
The engineers are changing processes to reduce the number of machining operations, aiming to produce most parts using a ‘one-hit machining’ process, while also addressing multiple parts at a time. Both of these require feedback from the spindle mounted Renishaw touch probes, enabling the machine to use its datum shift function and relate machining to previously machined features after indexing.
A good example is a ‘rod-eye’ component, re-designed so it could be made in three ops, all on the same machine and with one set of fixturing. The raw billets of material are loaded in a matter of minutes, after which the Renishaw spindle mounted touch probe is used to find the position of the billet accurately and adjust the part offsets, to which the machining program refers.
Once this op is finished the operator moves the part onto the next fixture, rotating it to address the next face. The touch probe then finds the position of the previously machined features, again adjusting the offsets in a few seconds.
From 1½ hours to set a job for 4½ hours of machining, the new HAAS CNC machines with Renishaw touch probes allow Sewtec to accomplish the same set-up in 10 minutes, immediately freeing up 1 hour 20 minutes to cut more metal. This has enabled the company to increase the productive hours by 850%, but with only five more machines.
Investments in Haas technology
Sewtec bought their first machine tools 15 years ago with two Bridgeport knee mills followed by a Bridgeport VMC with spindle and tool setting probes. Sewtec currently has 11 machine tools, of which 9 are from HAAS in a combination of VF2, VF3 and VF4 models, plus a VF9 for very large parts.
Moving towards unmanned production
Sewtec has decided to invest time in refining the set-up of its machines to facilitate unmanned production. A skeleton night shift has been created with a view towards achieving this objective with 4 operators running between 8 and 10 machines, depending on the production needs. The spindle probes and tool setting probes are an important factor in enabling this goal.
Renishaw Oceania represents the interests of the Renishaw Group in Australia and New Zealand.