Tame the Chatter Monster

"One of the most common lathe applications in manufacturing is the boring of components, also known as internal turning," said an ISCAR spokesperson. "The most widespread tools used for this type of machining operation are boring bars. When selecting a boring bar for internal turning operations, the depth of the machined hole versus its diameter influences the choice of the boring bar to be used. Boring bars that have large length to diameter (L/D) ratios can deflect and start to vibrate. This self-excited vibration is also known as chatter."

Chatter is detrimental to the safety and quality of machining operations. It can cause a rough surface finish, increase cutting forces, reduce tool life, decrease productivity and create irritating high-pitched noise. "This can sometimes create a `Chatter Monster,' but ISCAR has tools to help tame this problem," said the spokesperson. "ISCAR's anti-vibration tools are designed for operations that require large overhang. These tools include Dynamic Vibration Absorber (DVA) systems to increase damping and therefore stabilize the machining operation. ISCAR refers to these tools as the Whisper line."

ISCAR offers anti-vibration boring bars with length to diameter ratios of 7XD and 10XD, along with a wide range of diameters from .625" to 2.5" (16 mm to 60 mm). The Whisper line also includes a large variety of interchangeable heads to help meet the needs of many different turning applications, such as boring, threading and grooving. Standard steel bars are also offered with this system, affording users the opportunity to leverage their investment for use in standard type applications that do not require anti-vibration type tooling (up to 4XD).

"Combining Iscar's Whisper line with its latest grades and chipformers, along with following some standard turning practices as outlined below, will provide customers with a winning combination to help tame the Chatter Monster," said the spokesperson. Recommendations include:

• Bore accurate fitting soft jaws
• Use a split sleeve to hold the boring bar
• Make sure of sufficient coolant flow
• Use the smallest nose radius possible
• Use depth of cut larger than nose radius
• Use an insert with overall positive geometry
• Match the chipformer to the depth of cut
• Use an insert with a small hone and thin coating, such as a PVD coating
• Do not use wiper inserts
• Use an insert with small lead angle, such as 55°.

For more information contact:

ISCAR USA

300 Westway Place

Arlington, TX 76018

817-258-3200

info@iscarmetals.com

www.iscarmetals.com