Trochoidal milling is an application that produces a slot in difficult-to-machine materials more efficiently than using standard slot-milling methods. An end mill is used to machine the slot width using a circular movement and high-speed machining methods, essentially a combination of periphery milling and circular interpolation in the X and Y planes. Done right, it minimizes changes in the chip load and achieves high and constant feed rates, most commonly employing a low radial depth of cut with high axial depth of cut. It can save significant time and money by achieving higher speeds and feeds while greatly reducing loads at the cutting edge.
“There´s been an evolution of CAD/CAM solutions addressing the need of customers machining high-temp alloys,” says Mike Sperhake, WIDIA product manager. “These CAM solutions can create machining programs that improve tool conditions. They will keep forces and chip thickness constant. As we design tools for machining high-temp materials, it was easy for us to design especially for these improved conditions.”
The first results were WIDIA´s VariMill ITM solid-carbide end mills, followed by the VariMill IITM and VariMill II long. These tools optimize modern advances in CAM software and machine tool dynamics applications without losing the capability to work in weaker environments.
“WIDIA´s newest solution, the VarMill II ERTM, is a brilliant add-on for customers using the latest CAM programs,” Sperhake adds. Like the VariMill II, VariMill II ER end mills are engineered with five unequally spaced flutes. However, unlike with the existing VariMill product line, the eccentric relief (ER) available with this new tool´s cutting edges provides greater edge strength and enables high feeds and metal-removal rates. The VariMill II ER end mill has a different taper core than VariMill I and VariMill II for increased stability and robust performance, and also differs from its predecessors in that it is designed for center cutting.
VariMill II ER also is the first off-the-shelf tool to offer SAFE-LOCKTM by Haimer, which provides excellent stability, eliminates pull-out risk, and makes the tool more stable and concentric, overall.