Citizen has extended its modular build concept with its top international selling, mid-range Cincom L-Series CNC sliding head turn-mill centre range by introducing three variants of its L20. Each machine introduces selectable modules to provide user functions able to cater for workpieces from up to 20 mm or 25 mm bar size with the economics and versatility to produce both simple and highly complex component features.
The new L20 range is available as a standard 5-axis Type-VIII with 37 tool positions enabling further improvements in the ratio of cost-to-performance. A mid-specification Type-X has 44 tool positions and the additional flexibility created from a -Y2 axis for the back spindle and a high-end 7-axis Type-XII, has in addition the incorporation of a fully programmable swivelling 135 deg B-axis.
The latest machines also incorporate, in addition to a back toolpost, totally independent opposite and gang toolposts that are able to create a tandem tool motion to the machine’s highly productive overlapping processes capability.
Indeed, the versatility of the L20’s specification is further enhanced giving greater economic use of bar on shorter workpieces that can be invaluable on expensive material types. Here, a guidebush that can be removed or replaced within 30 minutes reduces the effect of long bar remnants. In addition, a selectable level of modular functionality can be made for the machine specification for example, there are two types of gang toolpost, five versions of opposite toolpost and three types of back toolpost.
The main spindle is powered by a 3.7 kW, 10,000 revs/min motor and the back spindle has a 1.5 kW, 8,000 revs/min drive. The driven tools on the gang toolpost are 1 kW, 6,000 revs/min while the opposite and back toolpost both have 0.75 kW, 7.500 revs/min drives. The B-axis driven tools are powered by 1 kW 8,000 revs/min motor.
The strategy being applied to the gang, opposite and back toolpost’s modular function package on the L20 machine range gives four driven tools with three manually adjusted single ended spindles from 0 to 90 deg on Type-VIII and -X machines and three driven tools and a swivelling B-axis with adjustment between + 90 and -45 deg with four double-ended spindles for front and back working.
On the opposite toolpost, which has the capability for pinch milling and deep hole drilling cycles, Type-VIII has options of three fixed tools and three fixed tools for deep hole operations and on Type-X and -XII choice of three fixed tools or three rotary tools and in double deck stacking, six fixed tools or six fixed tools for deep hole machining applications.
Meanwhile for the back toolpost, on Type-VIII, toolposts will accept either four fixed tools or four driven tools and on Type-X and –XII, four are fixed in a lower row as well as four driven tools in the upper row.
The Cincom high speed control now features even faster start-up and screen switching with on-screen program check and editing through the manual handle feed. Direct spindle indexing function gives further time saving as the spindle is still decelerating to stop at the designated index position in conjunction with C-axis commands. In addition, overlapping of the next cutting tool can be prepared thus avoiding any delay due to the current tool finalising its retraction from the job. Rapid travels are fast at 32 m/min in each axis and 8 m/min for Y.