Basics of turning center please check out below:
Lathes vs. Turning Centers: What’s the Difference?
You’ve probably seen the terms ‘CNC Lathe’ and ‘CNC Turning Center’ used interchangeably.
“[They’re] basically the same thing in my book,” said David Fischer, lathe product specialist at Okuma America Corporation.
Nevertheless, while there is no formal distinction between lathes and turning centers, the former term is often used to refer exclusively to simpler machines—those designed for turning operations alone. In contrast, the term ‘turning center’ usually denotes machines which integrate milling or drilling capabilities, or those with sub-spindles for performing secondary operations.
“In my opinion, a CNC lathe just strictly does turning; it’s a 2-axis lathe with X and Z axes and typically only one chuck,” said Rick Bramstedt, product manager for Mazak’s Advantec division. “A CNC turning center has milling capability, or a second spindle plus milling capability, and so it might have a Y-axis as well. We also call those Multi-Tasking Machines. That’s how I see turning centers: they offer more than just turning.”
Marlow Knabach, Chief Technology Officer for DMG MORI USA, agreed:
“I see it as the evolution of the lathe,” he said. “Most people called it a lathe in the past, but as CNC became more elaborate and with the addition of milling and sub-spindles, it evolved into a CNC turning center.”
Whether you’re working on a lathe or a turning center, the basic parts are the same.
Turning Center Configurations
“You have essentially two different types of CNC machining centers: the traditional, horizontal type that’s been around for quite some time, and then you have the vertical type, which spins the part like a top instead of spinning it like a car tire,” said James Petiprin, key account manager for EMAG, LLC.
“Horizontal probably makes up 60 or 70 percent of the market because it’s been around longer—every machinist learned on a horizontal lathe.”
Horizontal Turning vs. Vertical Turning
CNC turning centers come in either horizontal or vertical configurations. There are also inverted vertical turning centers, which reverse the position of the spindle and the chuck. All three machine types generally consist of the same basic components (i.e., headstock, carriage, etc.), but differ in their orientation. Deciding whether to opt for a horizontal, vertical or inverted vertical lathe depends on a host of factors, but there are some rules of thumb that can help you make the decision.
“The advantage with a horizontal lathe is that gravity pulls the chips away from the part,” said Knabach. “In other words, as you’re turning, all the chips fall down into the chip conveyor or bin.”
“The advantage of a vertical lathe is that gravity helps seat your part into your workholding,” he continued. “But the chips can be an issue, especially if your part is concave, since it can trap the chips internally. So you have the possibility of re-cutting your chips. The other concern with a vertical lathe is that the chips fall down into the spindle itself, so your guarding has to be extremely efficient.”
“Generally, horizontal lathes are more flexible since they can have longer bed lengths relative to spindle size,” said Fischer. “They can also use barfeeders and commonly have tailstocks, a rarity on verticals. On the other hand, if you are machining large diameter short parts, especially if they are heavy parts, the vertical lathe works well.”
“It’s primarily part size; that’s the biggest factor that determines between the two,” said Bramstedt. “When we look at small turning applications, a lot of automotive turning applications (transmission gear blanks, brake rotors, etc.) are done vertically and typically with a twin spindle. One benefit of that is that you have gravity working for you; when you put the part in the chuck, it seats itself. Another benefit is chip flow, again thanks to gravity—all the chips tend to fall away from the part into the pan or conveyor.”
“I’ve seen 30-inch diameter parts run on a horizontal machine,” he added, “but loading it is tricky because you need to push the part into the chuck and then hold it while you’re clamping it.”
Another factor to consider when choosing between horizontal and vertical configurations is the extent to which your turning center will be automated. “Horizontal lathes are usually easier [to automate] since the spindles and/or tailstock are at opposite ends of the machine and the turret can be positioned in such a way as to present minimal clearance issues,” said Fischer.
Getting the Most from Your CNC Turning Center
Lathes have been around for most of human history, and with good reason. Although the underlying technology has continued to advance, turning operations remain a vital part of many manufacturing processes.
That being said, turning is just one aspect of manufacturing among many.
Article Source: engineering.com