Tongtai VTX Drilling, Tapping Machines Provide High Precision
With rapid traverse speeds ranging to 2,362 ipm (60 m/min) in all axes and acceleration of 1.2 G, Tongtai’s VTX drilling and tapping centers are designed for high-precision, high-volume machining applications.
With rapid traverse speeds of 2,362 ipm (60 m/min) in all axes and acceleration of 1.2 G, Tongtai’s VTX drilling and tapping centers — available from Absolute Machine Tools — are designed for high-precision, high-volume machining. A fixed-column/moving-table design with Meehanite cast iron frames and roller-type linear guideways provide rigidity as well as fast, precise movement.
Two types of high-speed automatic toolchangers (ATCs) are available. The 21-tool, turret-type ATC on the VTX-5 and VTX-7 models offers tool change time of 1.4 sec. tool-to-tool and 1.9 sec. chip-to-chip. The VTX-5A and VTX-7A versions have a 20-tool, arm-type ATC that reduces tool change time to 0.8 sec. tool-to-tool and 1.3 sec. chip-to-chip.
The 7.5-hp, 12,000-rpm direct-drive spindle provides rigid tap speeds up to 6,000 rpm. An optional 24,000-rpm direct-drive spindle delivers speeds adequate for machining aluminum, magnesium and graphite parts. A BBT-30 (Big Plus dual-contact) taper suits rigid milling. Coolant through the spindle is standard, as is a spindle chiller.
The Mitsubishi M80A control features a 10.4" (264-mm) touch screen with intuitive smartphone-like operation. A high-response servo system with 1,000,000 pulse encoders increases speed and accuracy. A FANUC OiM-F control with 8.4" (203-mm) LCD screen is also available.
Running rotary milling cutters at the proper speeds and feeds is critical to obtaining long tool life and superior results, and a good place to start is with the manufacturer's recommendations. These formulas and tips provide useful guidelines.
One of the most common methods of tapping in use today on CNC machines is 'rigid tapping' or 'synchronous feed tapping.' A rigid tapping cycle synchronizes the machine spindle rotation and feed to match a specific thread pitch. Since the feed into the hole is synchronized, in theory a solid holder without any tension-compression can be used.
Creating threaded holes in titanium alloys calls for proper techniques based on an understanding of both the properties of these materials and the peculiarities of the tapping process.