Left to right:
MSP’s James Dent with Leonardo’s CAD/CAM engineer Keith Upton-Pittaway and tooling design engineer David MadiganLeonardo, the global industrial group, has experienced a remarkable leap in its production of complex carbon-fibre tiltrotor blades for one of its leading helicopter programmes after advanced CNC metrology solutions from
MSP cut production time from 20 weeks to just three days, a remarkable increase in productivity of over 4,500%.
As part of this, Leonardo has also seen their part alignment process reduced from days to just 5min, their estimated scrap rate reduced from 95% to 0% and their reliance on using fixtures for part alignment processes eliminated. Faced with the challenge of producing large, twisted composite blades that were deemed ‘impossible to manufacture’ by simulation software due to varying levels of distortion and a thin tip making them hard to fixture, Leonardo turned to MSP’s PerfectPart suite of metrology products.
David Madigan, Leonardo’s tooling design engineer, explained: “To align our parts, we would normally probe and measure parts using the CAD, but as the composite blades are often all different and never conform to this data, we had to find another way.”
Originally, Leonardo considered tackling the problem themselves using traditional manufacturing methods, but this was predicted to create an 18-20 week lead time and, was therefore, deemed an unsuitable option. The only feasible solution was metrology package MSP PerfectPart. It's NC-Checker and NC-PartLocator product modules give manufacturers error-free and right-first-time part production. NC-Checker was introduced as a standard operating procedure at Leonardo for its ability to assess the geometric performance of a CNC machine tool to check it is capable of machining parts to tolerance.
Low-volume and high-valueMr Madigan said: “The tiltrotor blades are low-volume and high-value, so you don’t want to risk scrapping any. NC-Checker allows us to monitor the machine tool in a simple way and gives us the confidence that no error on the machine will negatively impact the parts. Before we machine a blade, it is a stipulation that the software is run. Then, if something does go wrong, the first question is ‘Well, did you run NC-Checker?”.
NC-PartLocator was introduced to solve Leonardo’s main challenge of accurately aligning the blades despite the unknown amounts of distortion. NC-PartLocator is different to traditional part alignment methods. The software uses five-axis probing to measure a part on the machine and generate an accurate best fit alignment in 6deg of freedom.
Most importantly in Leonardo’s case, the software compensates for any discrepancy between the physical part location and the nominal machining program to show where the part ‘really is’ on the machine. The updated alignment is automatically uploaded to the controller and any misalignment errors are automatically removed.
Mr Madigan admitted the product shocked him: “NC-PartLocator’s alignment results can be quite surprising. The software often shows that the blade should be somewhere else entirely, even when it doesn’t look any different on the surface.”
It is also aided Mr Madigan’s fixturing routine: “I designed the fixtures based on the fact that you move the machine to the part instead of moving the part. All I needed to do was hold the part in position so it could be probed. It didn’t matter that the blades were all variable and the position wasn’t correct as I knew NC-PartLocator would compensate for that. It is night and day compared to traditional methods.”
The results certainly show this difference — using MSP as part of its processes, Leonardo has cut its estimated 20-week production time and 95% scrap rate to a stable three-day production time with a potential for 0% scrap rate. From parts that were deemed ‘impossible to manufacture’ to a manufacturing process that takes three days, Leonardo’s transformation is an example of how powerful advanced manufacturing metrology can be for composite and complex machining tasks.