Product category:
CAM, CNC and production management software
News Release from: Delcam | Subject: Race Line Machining.
Edited by the Engineeringtalk Editorial
Team on 03 November 2004
CAD CAM specialist's machining wins US
patent
Delcam has been granted a US patent for its machining technique, Race Line Machining.
Delcam has been granted a US patent for its machining technique, Race Line Machining Only available in the company's Powermill CAM software, it is claimed to offer increased machining efficiency through higher material removal rates and shorter toolpaths, while also reducing costs by protecting cutting tools and machine tools from wear and breakages
Delcam said it is well known that the main requirement for high-speed machining, especially at the roughing stage, is to use toolpaths that minimise any sudden changes in direction and keep the loading on the cutter as consistent as possible.
The company believes Race Line Machining is a novel variant on conventional offset machining.
With the conventional approach, the roughing passes are calculated using a consistent step-over between each pass.
That can result in more complex toolpaths than are necessary, with any complicated detail in the machined shape being duplicated in every toolpath.
As a result, the machine tool must slow down for every toolpath when this section is reached to avoid damage to the cutter.
As well as increasing the overall machining times, the continual changes in feed rate reduce the tool's cutting efficiency.
With Race Line Machining, Delcam said that the roughing passes are progressively smoothed out as the toolpaths move further from the main form.
The degree to which the toolpaths change from the simple offset can be controlled by the user.
Whatever value is set, Powermill would ensure automatically that the toolpaths never diverge to the extent that material is left uncut.
The result is that, by the time the edge of the part is reached, the toolpaths will usually be much smoother and will often be almost straight.
The use of Race Line Machining gives much smoother toolpaths, especially when roughing mould cores including significant upstands in their design claimed Delcam.
That means that high-speed cutters can be used at their optimum feed rates for a much larger percentage of the job.
At the same time, the elimination of many sudden changes of direction reduces the rapid changes in loadings that can lead to cutter breakages and damage to critical machine tool components, including the spindle.
Delcam believes that the full benefit of Race Line Machining would be gained if it was used in combination with another Powermill strategy, trochoidal machining, whenever the tool meets a high engagement.
Using a trochoidal shaving action to remove material in these areas further contributes to a lower, more consistent level of load on the tool.
Together, these techniques allow a move from high-speed machining to high-efficiency machining, using newer cutter designs where cutting is possible with the side of the cutter as well as the tip.
With high-speed machining, it is normal to set small step-overs and step-downs.
With high-efficiency machining, a much deeper cut is possible, even though the step-over must be kept small.
This deeper cut means that the material removal rate is much higher, even though the feed rate will be lower than the maximum possible with high-speed machining.
Race Line Machining contributed to an overall reduction in machining times of more than 50 per cent at Azaleia, the largest footwear manufacturer in Latin America said Delcam.
"The mould tool for a sandal would typically take 40 hours to be machined.
With Powermill, it can now be finished in 18 hours," claimed Jeferson Georg from the company's mould production R and D Group.
It also helped in a big reduction in cutting tool costs, he commented.
"Tooling costs, due to breakages, used to reach $12,000 per year, whereas today breakages have been reduced to a minimum," according to Georg. Request a free brochure from Delcam ...
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