Ramp Recess Turning Operations

The information in this section will help you create and edit Ramp Recess Turning operations in your manufacturing program. This type of operation is suitable for machining hard materials using round ceramic inserts, thereby minimizing wear and cutting stress.

The Ramp Recess Turning operation allows you to machine a recess by means of a One Way or Zig Zag tool motion.

You can specify:

• external, internal, frontal, or inclined machining according to the type of area to machine
• various approach and retract path types
• various plunge and lift-off options with specific feedrates
• part contouring
• rework
• tool output point change.

The following topics are dealt with in the paragraphs below:

• Tools
• Geometry
• Machining Strategy Parameters
• Feeds and Speeds
• Tool Compensation
• Macros.

Tooling for Ramp Recess Turning

The following tooling may be used:

• External and Internal insert-holders with round inserts. 

Note that the following attributes may influence machining (they are located on the Insert-holder's Technology tab):

• Trailing angle
• Leading angle
• Max Recessing Depth
• Max Boring Depth.

These attributes take tooling accessibility into account and may reduce the machined area.
However, you can use the Insert-Holder Constraints option on the operation editor to either ignore or apply these tooling attributes. You can replay the operation to verify the influence of these attributes on the generated tool path.

Note that the Insert-Holder Constraints setting does not influence the Flank Gouging Angle or the Entry and Exit Flank Angles defined in the operation editor.

Geometry for Ramp Recess Turning

Part and Stock profiles are required. They can be specified as follows:

• select edges either directly or after selecting the By Curve contextual command. In this case the Edge Selection toolbar appears to help you specify the guiding contour.
• select the Sectioning contextual command. Please refer to Sectioning for details of how to use this capability.
  Please note that the sectioning selection method is not associative.

Orientation for Ramp Recess Turning

The following Orientations are proposed: internal, external, frontal and inclined.

The selected Orientation defines the type of geometric relimitation to be done between the stock and part geometry in order to determine the area to machine. For an inclined orientation you must specify the Angle of Incline.

Part and Stock Offsets for Ramp Recess Turning

• Stock offset, which is defined perpendicular to the stock profile
• Part offset, which is defined perpendicular to the part profile.
• Axial part offset.
• Radial part offset.

Offsets can be positive or negative with any absolute value. The global offset applied to the part profile is the resulting value of the normal, axial and radial offsets.

Unsupported Geometry for Ramp Recess Turning

In a case like the one shown in the figure below, if the depth of cut is not sufficient, it is not possible to reach the righthand flank.

A warning message is issued recommending you to machine the profile in two operations.
Other possibilities to work around the problem are:

• add an offset to the profile
• increase the depth of cut.

Machining Strategy Parameters for Ramp Recess Turning

Path Definition for Ramp Recess Turning

• Ramp Recess Turning Mode: One Way or Zig Zag
• Max Depth of Cut
  This option is used to specify the maximum distance between passes.
• Machining Tolerance
• Machining Direction
  For Zig Zag tool motion, you must specify a first cutting direction as follows:
  • To or From Head Stock for Internal and External machining
  • To or From Spindle for Frontal machining
  • To Right or Left of Recess for Inclined machining.

  When a part profile has multiple recesses (that is, a non-convex profile along the cutting direction), only the first recess along the specified direction is machined.

• Entry and Exit Flank Angles (for One way mode only).
  The insert geometry is taken into account to avoid collision by reducing the maximum slope on which machining can be done. Defining Entry and Exit Flank Angles on the operation allow you to further reduce the area to machine.
  
  Note that leading and trailing angles can also be defined on the insert-holder to define the maximum slope on which machining can be done. In this case and if the Insert-Holder Constraints setting is applied (see above), the angles that reduce the slope the most will be taken into account.
• Flank Gouging Angle (for Zig Zag mode only)
  Angles of the insert are taken into account to avoid collision by reducing the maximum slope on which machining can be done. Defining a Flank Gouging Angle on the operation allows you to further reduce the area to machine.
  
  Note that a gouging angle can also be defined on the insert-holder to define the maximum slope on which machining can be done. In this case and if the Insert-Holder Constraints setting is applied (see above), the angle that reduces the slope the most will be taken into account.
• Under Spindle Axis Machining
  For Frontal or Inclined machining, this option allows you to request machining under the spindle axis.
• Part Contouring
  You can specify if contouring is required by means of the proposed check box.
  The part profile is followed at the end of recessing. This is done by machining down the sides of the recess in order to clear the profile.

Plunge and Lift-off for Ramp Recess Turning

• Angle and Distance before Plunge
  Define the plunge vector before each new pass with respect to the cutting direction.
• Lift-off Distance and Lift-off Angle
  Define the lift-off vector at the end of the last pass with respect to the cutting direction. The figure below shows the effect of a positive lift-off angle (external machining is assumed).

• If Rework mode is set, the following options are available:
  • Distance before Rework Plunge
  • Angle before Rework Plunge.

Feeds and Speeds for Ramp Recess Turning

Speed unit can be set to:

• Angular: spindle speed in revolutions per minute
• Linear: constant cutting speed in units per minute

then you can give a Machining speed value.

You can also set a Maximum spindle speed value for the operation (by default, this value is the same as the Maximum spindle speed set on the Part Operation).

The following feedrates can be set to either Angular units (length per revolution) or Linear units (length per minute):

• Machining feedrate
• Lift-off feedrate
• Contouring feedrate
• Plunge feedrate
• Light loading feedrate
• Air cutting feedrate

Dwell setting indicates whether the tool dwell at the end of each path is to be set in seconds or a number of spindle revolutions.

Feedrates are also available for air cutting trajectories such as macro motions and path transitions.
Note that RAPID feedrate can be replaced by Air cutting feedrate in tool trajectories (except in macros) by selecting the check box in the Feed and Speeds tab page .

You can select Air Cutting feed-rate as Linear (feed per minute) or Angular (feed per revolution). When you select it as Angular the unit is set to mm_turn, the unit is set to mm_mn for Linear.

The changes in unit of Air cutting feed-rate, are also reflected in APT file output. Calculated cycle time in Properties dialog box of MO also get changed. There are changes in total time and machining time on tool path replay dialog box.

Please note that decimal values can be used for the number of revolutions. For example, when machining big parts that have a large volume, it can be useful to specify a dwell using a value of less than one revolution (0.25, for example).

Tool Compensation for Ramp Recess Turning

You can select a tool compensation number corresponding to the desired tool output point. Note that the usable compensation numbers are defined on the tool assembly linked to the machining operation. If you do not select a tool compensation number, the output point corresponding to type P9 will be used by default.

Note that the change of output point is managed automatically if you set the Change Output Point option.

If the output point is consistent with the flank of the recess to be machined, the output point is changed when the other flank of the recess is machined.
At the end of the operation, the output point is the same as it was at the start of the operation. See Changing the Output Point for more information.

Approach, Retract and Linking Macros for Ramp Recess Turning

The following Approach and Retract macros are proposed: Direct, Axial-radial, Radial-axial, and Build by user.
The selected macro type (Approach or Retract) defines the tool motion before or after machining.

Various feedrates are available for the approach and retract motions (RAPID, lead-in, lift-off, and so on). Local feedrates can be set to either Angular units (length per revolution) or Linear units (length per minute).

Linking macros, which comprise retract and approach motion can also be used on Ramp Recess Turning operations.
Approach and retract motions of Linking macros are interruptible. It can be useful to interrupt an operation when the foreseeable lifetime of the insert is not long enough to complete the machining.

See Define Macros on a Turning Operation for more information.