A Powerful Trio

Gary S. Vasilash

Fast Operator According to the folks at Enshu (USA) Corp. (Elk Grove Village, IL), their E130 drilling and tapping machine is the world's fastest.

Fast Operator

According to the folks at Enshu (USA) Corp. (Elk Grove Village, IL), their E130 drilling and tapping machine is the world's fastest. What do they mean by fast? Consider this: the spindle, which is protected by an air-curtain, operates at 10,000 rpm. It can perform rigid tapping at 6,000 rpm. It's not just a matter of how fast a spindle can get to spin. It is equally (or arguably more) important how fast it can get from 0 rpm to its top end. In the case of the E130, that rate, the acc/dec rate, is 0 to 6,000 rpm in 0.1 sec.

Because drilling and tapping machines perform at least a couple of different operations (drilling and tapping, and, in the case of the E130, it can do even more: it can be used to do some milling of bosses, flanges and the like), and because not all of these operations are going to be performed precisely the same time after time (e.g., different sized holes are likely to be put into a part), the machine is equipped with a fast toolchanging capability: 1 second. And last but no less important, the E130 moves around quickly, as well: it provides 1,968 ipm rapids in all axes.

Changed Atmosphere

To hear that welding is being done in an inert gas atmosphere is common. So much so that people—even those who aren't directly connected with the process—toss off "TIG" and "MIG" without even thinking twice that the "IG" of those acronyms refer to "inert gas." (In case you're curious, the "T" is for tungsten and the "M" is for metal.)

But who has ever heard of a machining operation that involves inert gas?

Well, now you have: the EV450 vertical machining center employs a nitrogen-rich, inert atmosphere for machining. Patents have been applied for.

The reason why is actually quite simple: by removing water, oxygen and carbon gasses from the machining zone, the amount of oxidation that typically occurs at the tool/chip interface is minimized. As oxidation is one of the contributing factors to tool wear, this means that tool life can be enhanced. During tests, Enshu engineers have increased tool life by three to five times.

There is also the possibility of eliminating or limiting coolants in some applications. Dry machining may, indeed, be a practicality.

As for the EV450 itself, the machine is based on heavily ribbed castings. It is fitted with a 40-taper, direct-drive, 10,000 rpm spindle that can reach maximum rpm in 1.8 seconds. Rapid traverse moves (there is a traveling column for the X and Y axes) are made at up to 1,574 ipm.

All the Right Moves

Material removal at a rate 50% faster than is the norm. Increased tool life. Chatter elimination. Clearance so that already cut chips aren't cut—again and again and...

Sound good? Well, that's what's being reportedly offered on the JE60 horizontal spindle machining center. The secret, which shouldn't be at all surprising nowadays, is based on software.

Specifically, the JE60 can be used for trochoid, or variable-arc, pocket milling. The toolpath generated for this has the cutter describing circles that change in size as the tool goes cutting along the programmed path. As a result of the way the path is setup, there are no corners or reversals, which means that acc/dec losses are eliminated.

One of the reasons why the aforementioned characteristics can be achieved is that the cutting tool employed is of a smaller diameter than would ordinarily be used for milling a pocket of the same size. Consequently, there is more air cooling of the cutter and improved chip evacuation.

The JE60 has a 24-in. work cube. It is equipped with a 40-taper, 41-hp, AC integral-drive spindle that's chilled, lubricated, and capable of achieving 13,000 rpm. The machine offers 1,181 ipm rapid traverse rates and 1-second toolchanges.