10/1/2009 | 4 MINUTE READ

Advances in Metalcutting

Here are some new tools and machines that you should be aware of.
Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Grooving & SlittingGrooving and slitting ops are facilitated by a new family of tools launched by Sandvik Coromant (coromant.sandvik.com/us). There is the CoroMill 329 cutter, which deploys CoroCut two-edge inserts and a strong V-rail clamping interface.


Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Grooving & Slitting
Grooving and slitting ops are facilitated by a new family of tools launched by Sandvik Coromant (coromant.sandvik.com/us). There is the CoroMill 329 cutter, which deploys CoroCut two-edge inserts and a strong V-rail clamping interface. Cutters are available in both 4- and 5-in. diameters. The groove widths achievable range from 0.098 to 0.157 in., and a maximum depth of 0.709 in. There's the CoroMill 331 for slot milling with eight-edge inserts. CoroMill 327 is engineered for internal grooving, chamfering, and threading holds over 0.382 in. in diameter. And CoroMill 328 is for threading and grooving external grooves and holes over 1.535 in. in diameter.


Five-Axis for Speed & Accuracy
Significant savings can be achieved by using five-axis machining rather than three-axis for finishing of hard materials such as those used for dies and molds, according to a study form Yasda Precision America (yasda.com). Specifically, they used the new five-axis YBM-Vi40 jig borer with a R1 ballnose end mill. Because of the ability to tilt the workpiece, cutter length requirements were reduced. Because of the shorter tool length, cutting feedrates were much higher than was possible on a three-axis machine: 2,000 mm/min compared with 400 mm/min. What's more, a superior surface roughness was achieved: Ra 0.25 µm compared with Ra 0.90 µm. The new machine offers spindle speeds up to 24,000 rpm and a rapid traverse rate of 20,000 mm/min on the X, Y and Z axes. It has a 60-tool automatic toolchanger. Control is a Fanuc 31i-Model A5.


Performance & Accuracy
High performance machining meets high accuracy in the FH1000SX horizontal machining center from Toyoda Machinery (toyodausa.com), which has a 39.4 x 31.5-in. table to accommodate large parts. It has 63 in. in X-axis travel (column) and 72.8 in. in Z (work table travel), as well as 55.1 in. in Y (spindle head vertical travel), which means that it has a capacious work envelope. It has a 40-hp, 6,000-rpm spindle that offers 440 lb-ft of torque, so it is capable of serious metal removal with CAT 50 taper tools. Yet at the same time, there is superior surface finish capability, as it offers a linear positioning accuracy of ±0.00012 in. and a repeatability of positioning of ±0.00006 in. The machine has dual ballscrews on the column to help assure rigidity and accuracy during machining. The 360,000-position NC table offers an indexing accuracy of ±7 arc seconds and an indexing repeatability of ±3.5 arc seconds.


Turning Innovations
New innovations for turning are offered by ISCAR (iscarusa.com) via its HELITURN Lay Down (LD) family. Among them are new WNMX, CNMX, and DNMX inserts, which feature high positive radial, helical cutting edges and positive rake angles, a combination that reduces cutting forces. They feature an 88° corner angle, which provides increased strength, which means that these are inserts designed for heavy machining and fast material removal. Additionally, there are new lever lock external holders and boring bars for HELITURN LD inserts, designed to accommodate the rake and edge configurations, facilitating high machining parameters, low cutting forces and reduced vibrations, particularly in internal ops.


Large Parts & Hardmilling
Large-part, high-speed hardmilling is the objective of the V56i vertical-spindle machining center from Makino (makino.com). Equipped with a 41.3 x 21.6-in. table, it is capable of accommodating parts measuring 41.3 x 28.3 x 17.7 in. and weighing up to 1,760 lb. And these can be hard parts, as in 50+ HRc. Part of the reason why it can do this without chatter during machining is a shorter spindle than is the norm. The spindle, which has a CAT 40 taper (as well as HSK variants), is powered by a standard 25-hp drive that runs the spindle up to 20,000 rpm. The machine offers a 787-ipm rapid traverse rate, which is the same as the cutting feedrate. A specially engineered spindle lube system controls spindle thermal growth, which can occur during long high-speed hardmilling operations.


Machining Strategy
Pockets, steps, slots, channels, and other prismatic shape machining can be facilitated by a new toolpath engine, VoluMill from Celerative Technologies (volumill.com). The technology, for which a patent is pending, is a software for generating toolpaths that is CAM system neutral (e.g., it can be integrated with GibbsCAM and Mastercam). Presently a 2.5-axis product (reportedly going to 3-axis), it generates toolpaths that manage material removal in a controlled manner so that there are no abrupt changes in direction, tool load, or removal rate, thereby providing the means to run at higher speeds and feeds while extending tool life. Unlike conventional high-speed machining strategies, it doesn't depend on shallow axial or radial cuts, yet it facilitates high-speed material removal. According to Celerative CEO Terry Sorensen, some users of the product have reduced "cycle times by more than 50%."


Small Part Multitasking
Say you have a small part that is complex. A part that needs turning, milling, drilling, tapping, and boring. What do you do? You could get a few machine tools to handle it. Or you could get a single machine with a comparatively small footprint (58-ft2) that has clever interior handling that can do all of these processes on barstock (up to 2.56 in.). It's the INTEGREX i-150 from Mazak (mazakusa.com). It features a horizontal 15-hp main spindle that operates at up to 5,000 rpm for turning, and it features C-axis control. In addition to which, there is a 10-hp, 12,000-rpm milling spindle that's mounted on a vertical, rotating B-axis rather has a range of -10° to +190°. The Y-axis range is ±3.94 in., the X- and Y-axes travels are 14.57 and 17.13 in., respectively. The swing is 15.57 in.