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(Original author: NVsion – www.nvision3d.com )
Nissan has chosen NVision's ModelMaker non-contact laser scanning system to help reduce costs in the manufacture of pressed car panels and the tooling used to produce such items.
Today subsequent, multiple, worldwide installations are seeing Nissan well on the way to halving its gauge costs in this area within the next five years.
The multi-national car maker's quality team - established in Japan to ensure the adoption of best quality practice at all Nissan sites worldwide - determined that non-contact, laser-scanning offered significant operational, quality and cost benefits compared with methods using contact probes on Cartesian driven, coordinate measuring machines.
Further investigation led them to NVision. Subsequent orders have meant that this company is now equipping some 20 Nissan factories worldwide including locations in Japan, USA, Mexico, Spain, as well as the Sunderland plant in the UK.
Traditionally, panel measurement in the auto industry involves the use of checking fixtures which, although created from component CAD data, are susceptible to manufacturing tolerances and, even if checked on the best of Cartesian CMM's, can only be guaranteed to be accurate at a finite number of probed positions.
The use of such methods does not allow a comprehensive component inspection - particularly where complex pressed forms are involved; nevertheless it is still extremely time consuming, and demands a high skill and experience level to take and interpret readings.
Another significant downside to this approach is the lead-time and cost involved. A typical car set of press panel gauges will be between 55 and 60, and cost in the order of $1.9 million.
Nissan concedes that the total hard-gauging cost for a recent model was $6.7 million. It comprised some 120 gauges, and the on-going storage and maintenance costs are significant.
Nissans Sunderland facility alone is now on-course to achieve savings of $900,000 press panel inspection, by moving to 3D laser scanning.
The ModelMaker 3D scanning system comprises a non-contact optical measurement facility mounted on a Faro portable CMM. It can digitise an object in a fraction of the time taken by a touch-probe.
A low-powered laser scans the total surface of the component to produce 'data sets' rather than just measure key dimensions. The proximity of the measured points is so close and the number of readings taken are so great that dense 'point clouds' of data are recorded.
Dedicated software compares this information with original CAD data and enables all QA requirements to be met automatically.
At Nissan's Sunderland plant, QA engineer Ian Bargman offers an illustration of the productivity improvements and other benefits that ModelMaker gives them. Using the old method, a 'body trial' - taking some 300 measurements - could take about 20 hours, whereas ModelMaker can take up to 14,000 readings per second.
Bargman states 'Full panel analysis via ModelMaker enables us to know immediately if any aspect of a panel has fallen outside manufacturing tolerances - and, if so, by how much. This makes for considerable cost-savings in terms of die manufacture and reduced part rejection at the assembly stage'.
A further benefit is its use as a reverse engineering tool. Periodic scanning of press tools helps to create a record of their development history. In the event of tool damage this data enables a tool to be rebuilt to its true contemporary condition, as opposed to its original, theoretical condition.
Bargman concludes: 'Very simply, having ModelMaker available to us as both an inspection and reverse engineering tool is having a major, positive impact on the speed and quality of our manufacturing worldwide'.
Download: Nissan uses handheld scanner for panel measurement (PDF file)
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