In rare cases a larger diameter can be achieved up to the IC of the Cutter Ring. A clearance between the cutters and the work piece is required if Diameter is dictated by the inscribed circle between the cutter tips. DOC is dictated by the insert protrusion relative to the holder. Threading Inserts - To achieve a unique desired thread shape, a special form insert which matches the desired thread form is required.ģ. Servo Type Main Spindle so can achieve programmed speeds of 10 or 20 RPM.Ģ. The machine must be equipped with either a C-axis on the Main Spindle or Can Any Machine Be Used to Whirl? Not every machine can be used for whirling. As the heel of the cutter makes an exit path the direction of the finish pattern changes as the cutters pull up material as the part rotates into the cutter path the result is a cross hatch pattern.Īlthough Thread Whirling is quite simple there are a few parameters to understand:ġ.
#Findy whirling full
In the thread milling process the cutter path cuts on the way into the cut and up to the full tangent point. This is because the cutter only contacts the work piece at the full tangency of the cutting path. This cross hatch pattern would not be seen on any thread wall with a positive wall angle. As the heel of the insert exits the thread form the resulting finish leaves a cross hatch pattern. In the thread whirling process the cutter path enters and exits the cut in a radial arc which is similar to the thread radius direction. In a comparison to thread milling a 0° thread wall which is commonly found on the trailing side of a bone screws thread, the finish pattern of thread whirling is improved due to the tangential radial entry and exit of the cutter which leaves a uniform pattern. Burrs are also minimized due to a reduced chip load and longer tool life. Surface Finish –The improvement in surface finish by the thread whirling process is a result of the unique tangential cutter path and the increased rigidity. Chip load for whirling is considerably less than single pointing and combined with the increased edge strength it equates to longer tool life and increased production time.
Top notch or side screw inserts would required special holders or would need all of the clearance to be built into the cutter this would considerably weaken the edge strength. However, 6° is the usually the maximum angle found on standard anvils and the remaining clearance must be made up with relief on the insert itself. Lay down inserts may use an anvil under the insert that will accommodate some of the clearance issue. If the helix angle of the thread is 7° then the cutter clearance must be greater 7°.
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