Ken Emerick believes that, in spite of a difficult economy, manufacturers are wise to invest in technology that reduces cycle times, and consequently will lower perpiece production cost. Emerick’s shop, Emerick Machine Products in Burton, Oh., which specializes in precision machined parts in steel, brass, aluminum and other materials for customers in aerospace, mechanical fittings and precision part industries, did just that. The shop not only shaves costs now, but is ready for when incoming orders pick up.
As part of his technology-investment plan, Emerick installed a 65-mm bar capacity C200 mill-turn machine from Index Corp. that is already paying dividends. Thanks to faster travels, three independent turrets, and two Y axes, the C200 reduces cycle times up to 90 percent for one of the parts the shop produces. In addition, these faster cycle times will let Emerick replace several older machines with the one C200.
Not only that, prior to purchasing the machine, Emerick had Index prove its performance on one of the shop’s tougher parts. It was a 2.5-in.-diameter steel bar, which required a 1.75-in.-diameter through hole, bores at each end and grooves in those bores for retaining a bearing. The machine handled the part with no problems.
“With two Y axes, I can machine the top and bottom (180 degrees opposite) of a part simultaneously, saving cycle time. This can easily save us 50 percent with circular milling, slotting, porting, tapping or off-set drilling, and other machining operations,” said Emerick.
He added that Index showed him how capable the C200 is not only for hoggingout material, but also for holding tight concentricity tolerances. The company then demonstrated how what used to take Emerick 60 minutes to machine could be done in 6 minutes, and he quickly realized the machine could easily pay for itself.
The C200 comes with 5,000-rpm spindles and runs parts to 7.87-in. long. Three 14-position tool turrets, a 6.30-in. chuck size, and identical liquid-cooled main and counter spindles make for fast, cost-competitive production of medium complexity parts turned from barstock. The machine’s 42 tools, each of which can be driven, help Emerick produce difficult parts in single setups and with minimum cycle times.
Tools lock with only one screw and feature Index’s W-serration at the base of the toolholder, and an Index-specific improved VDI interface ensures repetitive accuracies of +/- 8 microns up to 3.94 in. from the mounting surface.
“Tools are held rigidly and do not move, making setups faster because we don’t have to align the holder anymore,” said Emerick. Also, the W-serration in the toolholders has increased tool life by 20 to 50 percent, depending on the material being cut.
Another key to reducing cycle times is the option of dividing machining operations through simultaneous machining. This is done with the C200’s two Y axes, one at the main spindle and one shared between the main spindle and the counter spindle. Each has a travel of 2.76 in.
Emerick pointed out that with such a capable counterspindle and three turrets, the simultaneous machining operations he can now program his machining time way down for every part he’s programmed. And, the two Y axes allow him to work on both sides of a part at one time, as well as perform simultaneous off-center machining.
Three tools can be at work simultaneously – driven or fixed – including backworking, and the counterspindle with a driven Z axis can be synchronized with travel of turret number three. Counterspindle pick-up from the main spindle happens in 1.5 seconds.
C200 turret slides move in the X-axis and Z-axis directions on an Index SingleSlide plate slide system. This system permits rapids up to 2,362.20 ipm and accelerations of 1G with maximum rigidity. The plate-type guideway of the turret slides also means turrets glide directly on the machine’s bed for high stiffness and dampening, and thus longer tool life and better surface finishes.
