Общий каталог Widia 2017 - страница 596

Technical Recommendations Separator Cut-Off System

(continued)

Eliminate chatter:

• Minimise tool blade and holder overhang.
• Minimise part overhang.
• Use strongest toolholder system.
• Use a more narrow width of insert.
• Chipbreaker might be too aggressive. (Call Technical Support.)
• Adjust speed and feed rate up or down.
• Hold workpiece rigidly.
• With a longer part, support with steady rest or live centre.
• Avoid machine dwell.
• Use S2 or X2 to reduce cutting forces.

Reduce cut-off nib on solid bar

or I.D. bur on tubing:

• Check tool height. Insert cutting edge should be on centre to 0,05mm above centreline of workpiece.
• To reduce nib on part, use a high lead angle-type insert. Lead angle on a cut-off insert reduces the nib, which remains on the workpiece. CAUTION: the higher the lead, the more tool-side defl ection.
• Use the narrowest possible cut-off insert to minimise the cut-off bur length.
• Reduce feed rate at the end of a cut.
• On most tubing-type parts, a 4° or 5° lead angle will be suffi cient.
• Add support to a long slender-type part.
• Maintain proper sub-spindle alignment.
• If nib or bur persists, call Technical Support about reducing hone size.
• Use small- or no-corner radius.

Eliminate built-up edge:

• Select proper grade for insert.
• Increase speed (RPM).
• Increase the feed rate.
• Use ample amounts of well-directed coolant (see Figure A on page E131).

Chamfer and cut-off operations:

• Use Separator S2 or X2.
• Groove or breakdown workpiece surface being machined.
• Machine the chamfer.
• For jobs requiring a chamfer on both ends of the part, begin by plunging to a depth just beyond the depth of the chamfers. Then, return to the part O.D. and profi le each chamfer individually. Finish the cut-off after completion of the second chamfer.
• Cut off the workpiece (see Figure C).

Figure C