SolidCAM iMachining - toolpath innovation [Video]

SolidCAM, which is distributed by a worldwide network of resellers, was established in 1984 and has sold more than 15,000 licences. The UK operation was formed in 2002 and is located in Barnsley, South Yorkshire. An easy confusion to make, due to its close association with CAD system SolidWorks, is that the two are the same company; they are not, SolidCAM is an independent company. And while it works closely with SolidWorks, having Gold Partner Status, and is sold by SolidWorks resellers as the CAM part of the solution sitting within SolidWorks as a fully integrated element, it is also available for use similarly within Autodesk Inventor, while the technology is also offered as a standalone system having its own CAD front end, or for use with other CAD platforms, where it has embedded CAD file import capability. But it is the SolidWorks connection that is underlined as of key importance by SolidCAM UK's Gordon Drysdale, with him adding that the CAD package is "one of the world's most widely-adopted 3D CAD system"; ease-of-use is the other overall SolidCAM strength, he adds. In addition to the full product, SolidCAM Xpress is offered for 2 1/2 D milling. Sales in the UK are split 50/50 between direct and as part of a CAD-led sale. IMACHINING PUSH With the launch of SolidCAM 2011 has come a concerted push behind the company's iMachining toolpath optimisation technology, following four years of development. The benefits of toolpath optimisation are claimed by its practitioners as reduced cycle times, improved tool life, improved surface finishes and reduced machine tool wear. As Machinery wrote in its previous article on the subject earlier this year (see here), toolpath optimisation can be considered as coming in two forms: as part of the toolpath creation process within the CAM system at the point of generating toolpaths for the first time; or as a post-CAM operation, where the output NC code is optimised. Toolpath optimisation is most helpful in roughing, but optimised finishing toolpaths are also generated by some systems, including SolidCAM's iMachining. A key attribute of optimised toolpaths generated within CAM systems is that they are not simple offsets of the machined part, but instead follow what can be described as novel paths. Image: A conventional toolpath is an offset of the finished geometry Image: iMachining toolpaths - morphing spirals; not simple offsets of finished geometry SolidCAM's iMachining generates optimised toolpaths and currently offers toolpaths covering 2.5D milling and 4-axis wrap, turning and mill-turn modules (including iMachining grooving and facing) with 3D coming, offers SolidCAM UK's Mark Stocks. Unlike some other systems on the market, SolidCAM's toolpath optimisation technology has been developed by the company itself and is the subject of a patent for unique features. iMachining adopts constant cutter engagement angle and constant chip thickness as main rules, as do others, but the claim is that, versus other similar, better established technology from competitors, the toolpaths generated by iMachining can be between 5-10% faster, while still offering extended tool life and superior surface finish versus non-optimised toolpaths. A pivotal difference between iMachining and these others toolpath optimisation systems is the ability to 'morph' toolpaths. SolidCAM's Morphing Spiral Tool Path is so called because, unlike the spiral tool paths in most other CAM systems, it gradually adapts to the shape of the area it has to clear, rather than symmetrically expanding in a circular fashion. This ability reduces machining time considerably. This may conjure up an oversimplified vision of what happens, because the progress towards a fully machined pocket (closed or open) is, in reality, interrupted by 'channeling' and 'separating'. Channel clears might be required to generate a narrow path between islands, while separating is where one solid area is cut into, say, two parts, allowing spiral morphing to be sensibly applied to clear each. So there may be a number of separate high efficiency morphing cycles, governed by the geometry being machined. In all of this, iMachining sees the cutter engaged with the material as much as is possible, avoiding material over engagement, diving, as well as air cutting. It also applies modified trochoidal cutting in channelling, such that the acc/dec rates are controlled at material engagement/disengagement. SAFE FIRST CUT And having done all this, the toolpaths can be taken straight to the machine and safely run, it is emphasised. The exact matching of the cutting conditions, coupled with the optimal subdivision of the area, supports successful first cut parts, with total machining time savings ranging from 40% to 85% on regular, mid-range machining centres, claims SolidCAM. iMachining achieves an average of more than 50% more area cleared by spiral tool paths than all other products that use spirals. A characteristic that reduces machine and tool wear and machining time, and increases product fatigue life. "That is what makes it possible to cut 62 HRC steel with 2 mm cutters 20 times faster than conventional milling," adds Mr Stocks. SolidCAM also claims that finish-cut surface is superior, because the software's iRest rough leaves a smoother and more even amount of material on the walls, while the feed of iFinish is matched at every point to the exact cutter engagement angle. The requisite number of contact points on the wall between the flute and the material has been one of the major discoveries that enables the iMachining Wizard to overcome potentially harmful vibrations and chatter, too. Image: iFinishing toolpaths featuring trochoidal moves The benefits of iMachining have been demonstrated by SolidCAM UK, both in partnership with Iscar, with which it works closely, and at customers' works. It is titanium machining that has been the focus of attention so far, says the company, with results achieved nothing short of stunning. In one case, a titanium part was machined 1 hour faster, at a feed rate increased from 36 m/min to 110 m/min, using a 20 mm, 5-flute cutter at 40 mm depth of cut and 0.1 mm per tooth feed. Undertaken on a Mazak Variaxis machine at Iscar Tools, Birmingham, at the same time, tool life and surface finish were also better. In brief, the process to apply iMachining is this. The geometry is created/imported, and the cutter, CNC, material and machine are all defined by selecting entries from databases. Image: The Machine Database screen These databases can be user expanded and modified. The machine database, for example, contains the spindle power of the machine, maximum spindle speed, maximum feedrate, positioning feedrate and the efficiency of the drive. The material database contains data such as cutting surface speed, various cutting angles and, importantly, a power factor that defines the power required to remove 1 cubic centimetre of material per minute. Settings can be automatic or manual. Image: The Material Database screen Using the 'technology' form, rough, rest or finish machining is selected, and various other elements are defined, including links between toolpaths. Then comes a critical part, the use of the 'technology wizard'. Two key parameters that can be altered here are the step down and cutting aggression (low to high). The appropriate step-down is achieved by the system looking at the cutter helix angle and allying this with a sensible number of contact points. A colour code system is actually used qualify the choice – red is no good; yellow is acceptable; green is good. Image: The Technology Wizard screen Image: Another Technology Wizard screen, setting the angle of engagement minimum and maximum levels TURBO MACHINING, IF YOU LIKE The ability to set the machining level means that users can set off cycle time reduction against tool life. There's also a Turbo level (accessed via the material form), that allows users to go beyond what might be considered a safe initial top limit. Following iRoughing, iRest machining and then iFinish machining take place, employing similar rules about constant chip thickness and the maintenance of a specified cutter engagement angle, for example. SolidCAM already has four of its UK users applying iMachining, while it is also involved in numerous discussions. Titanium is very definitely one of the major draws, but there will be benefits for other materials, too. NOTE 1: The accompanying video shows a 20 mm cutter machining titanium at Iscar's Birmingham facility NOTE 2: The PDF below is a White Paper describing iMachining at length First published in Machinery, July 2011