PreciseBits EM2E8/EM3E8 Tapered Stub Mill

Overview

After more than 2 years of development, PreciseBits has introduced the EM2E8 / EM3E8 family of tapered-stub PCB Trace Isolation Tools. These bits feature a flute design that has been fine-tuned to ensure very efficient debris removal, even at full plunge. Much stronger than a conventional V-tip bit, they cut at higher feed rates, producing a superior edge finish with a longer cutting life. Extensive testing in the field confirms that they outperform V-tip (1-flute and 2-flute) mechanical etching bits in all aspects of trace isolation and copper rubout. They are, in short, the next generation of PCB mechanical etching tool.

The spiral geometry of the tool ensures efficient debris removal while the cutting edge geometry virtually eliminates chatter at high feed rates. The 15° taper angle minimizes cut width variation due to poor substrate flatness. Applications include printed circuit board trace isolation, engraving plaques, awards, medallions, and custom jewelry fabrication and marking.

• Geometry - 2 & 3-flute, 15° taper, P-stub tip
• Length - 1.42" (36mm) ±0.010"
• Tip angle - 15° +0.0° -2.0°
• Diameter Tolerance -± 0.0002" (0.005mm)
• Shank dia. - 0.1250" (3.18 mm) +0.00, -0.0002"
• Max runout (TIR) - < 0.0002"
• Max. depth of cut - varies with tip diameter
• Material - solid submicrograin carbide
• Ring Set - 0.800" ± 0.004" (custom depth available)
• Operating RPM - CNC certified operation 20k RPM to 100k RPM

Applications

• Print circuit trace isolation
• Copper rubout on printed circuit boards
• Engraving plaques, awards, medallions, and labels
• Custom jewelry fabrication and marking

Application Data

• Tool Type: Tapered End Mill
• Diameter (D) = tip diameter
• Included Angle (A, total angle) - 15°
• Stepdown = Depth per Pass, Pass Depth - 1 tip dia. max.
• Depth of Cut (DOC):
• 0.0039" tip - 0.010" (0.25mm)
• 0.0051" tip - 0.010" (0.25mm)
• 0.0071" tip - 0.010" (0.25mm)
• 0.0100" tip - 0.020" (0.51mm)
• 0.0150" tip - 0.030" (0.76mm)
• 0.0200" tip - 0.030" (0.76mm)
• 0.0250" tip - 0.035" (0.89mm)
• Stepover (for final cleanup pass) = 10% tip dia.
• Stepover (for roughing, clearance pass) = 40% tip dia
• Spindle RPM (SPEED) = 5 KRPM to 60 KRPM
• Feedrate (IPM) = Depends on the material being cut.
• Plunge rate = 5 IPM to 25 IPM (again depending on material being cut)

Bit sizes