Turning Profile

Profile is used for both roughing and finishing the part. Machine Outside Diameter (OD), Inside Diameter (ID) and Face profiles. You can control the cut direction, tool orientation and limit the toolpath area by using Geometry - Confinement boundaries.



Access:

Ribbon: CAM tab Turning panel Profile

Tool tab settings

Tool

Select a turning tool from the library, or create a new turning tool.

Coolant

Select the type of coolant that should be used with the tool. Output options will vary depending on the machine capabilities and machine postprocessor configuration.

Use Tailstock

A tailstock can be used to support the open end of the workpiece. This is particularly useful when the workpiece is relatively long and slender, or large and heavy. Failing to use a tailstock can cause the workpiece to flex while being cut, causing poor surface finish (chatter) and inaccuracies.

For this option to take effect, your machine needs a programmable tailstock and your post processor has to be configured to write the code your specific machine needs. Once configured, the post will output the appropriate code to extend the tailstock forward at the beginning of the operation and retract the tailstock backward at the end of the operation.

Turning Mode

This setting determines whether the tool will machine on the Outside Diameter, the Inside Diameter or radially across the Face of the part. This select also determines the approach/retract direction for the cut.
Outside profiling

The tool approaches from/retracts to the outside of the stock and machines along the spindle axis (axially) depending on the Pass Direction setting (below).

Face profiling

The tool approaches from the front and machines radially. The cut can be outside to inside or inside to outside, depends on the Direction setting (below).

Inside profiling

The tool approaches from/retracts to the centerline and machines axially depending on the Pass Direction setting (below).

Direction

In conjunction with the Turning Mode, this setting determines the tool cutting direction
Note: Not all tools can cut in both directions. Consult your tooling supplier to select an appropriate tool.
Front to back

Select this option to cut from the front side of the stock, towards the back side, i.e. towards the main chuck.



Back to front

Cuts from the back side, toward the front side. Away from the chuck. For tools with special geometry where chip thinning control is important. See the Use Back Cutting option shown on the Passes tab.



Both ways

This option allows the tool to cut in both directions. The result is a back and forth cutting motion. Ensure that you are using a tool that can cut in both directions, when selecting this option.



Grooving (Undercuts)

Allows the tool to cut below the face of the part for undercut areas. If Disabled, the tool can only create cuts that move straight along the outer face of the stock. When Enabled, the tool can plunge into the stock in narrow areas to relieve undercuts. These are the options to control plunge direction.

Dont Allow Groove.

With this setting the tool will not dip into any undercut areas of the part.

Allow Radial Grooving.

The tool will only plunge in areas that undercut the OD/ID of the part, without violating the model.

Allow Axial Grooving.

The tool will only plunge in areas that undercut any faces of the part, without violating the model.

Allow Radial and Axial Grooving.

The tool will plunge into any areas that undercut the part, without violating the model.

Allow Radial and Axial Grooving.

Same as above. Note the efficiencies of selecting the right tool.

Pass Direction

Specifies the direction of the passes.





Pass direction @ 0 degrees

Pass direction @ 30 degrees

Pass direction matches part

Tool Orientation

You can change the direction the tool points. This is most useful if your lathe turret has a programmable B axis. Your post processor will need to support posting from this value. However you can simply set your tool in the turret/holder at a fixed angle.


Tool Orientation @ 45 degrees.

Tool Orientation @ 90 degrees.

Tool Clearance - Back/Front

Specifies an additional tool clearance angle for the front and back edges of the insert. Sets the amount of relief between the part and the cutting tool. Allows for a more gradual entry into the part and exerts less pressure on the tool. Changing the Back Clearance will adjust the Front Clearance to the same amount. You can manually change the Front to a different value.

Back = 0° and Front = 0° (No adjustment)

Clearance is not changed. The toolpath will feed in along the tools actual front & back clearance angle.

Back = 15° and Front = 15° (Equal adjustment)

Additional clearance for the back edge and the front edge are adjusted with an equal amount of clearance.

Back = 20° and Front = 30° (Independent adjustment)

Additional clearance for the back edge and the front edge are adjusted with independent clearance amounts.

Use Constant Surface Speed

Enable to automatically adjust the spindle speed to maintain a constant surface speed between the tool and the workpiece as the cutting diameter changes . Constant Surface Speed (CSS) is specified using G96 on most machines.

Note: For more information, see the Inventor CAM Help topic: About Turning Feeds & Speeds.

Surface Speed

The cutting speed expressed as the speed of the tool across the part surface. Expressed as Ft/min or M/min depending on the current Units setting.

Spindle Speed

The rotational speed of the spindle.

Maximum Spindle Speed

Specifies the maximum allowed spindle speed when using Constant Surface Speed (CSS).

Use Feed per Revolution

Enable to switch from Distance over Time (In/Min or MM/min), to Feed Per Revolution (IPR or MMPR). This type of feedrate creates a constant chip load regardless of the spindle RPM.

Cutting Feedrate

Feed used in cutting moves. Input based on the Use Feed per Revolution setting and the current Units.

Lead-In Feedrate

Feed used when leading in to a cutting move. Input based on the Use Feed per Revolution setting and the current Units.

Lead-Out Feedrate

Feed used when leading out from a cutting move. Input based on the Use Feed per Revolution setting and the current Units.

Geometry tab settings

Front / Back Confinement

Used to limit the toolpath by Confining an area. Toolpaths can be contained within a specific region. Front/Back Confinement Mode lets you set the reference point for defining the containment area of the toolpath and Offset lets you adjust the boundary positive or negative from that reference. You can use these options to extend the toolpath past the model for a longer cut.

Front Confinement is show in Orange - Back Confinement is shown in Green.

Front / Back Mode

Specifies the reference position for the Front/Back Confinement boundary. These are the options for selecting the reference.

Chuck Front

Offset

Specifies the distance to shift the machining boundary from the reference position shown above. You can specify a positive or negative distance from the reference point, or dynamically drag the position with your mouse. Front boundary is shown in Orange and Back boundary is shown in Green.

Front of Model Reference with .200" Offset

Selected Reference (blue edge) with -.250" Offset

Rest Machining

Specifies that only stock left after previous operations should be machined.

Disabled

The toolpath will clear out the entire area selected.

Enabled

The toolpath will only remove sections of the material that were not cleared out by the previous toolpath.

Rest Material Source

Specifies the source from which the rest machining is to be calculated.

Radii tab settings

Radii Options for Outside Turning .

Radii Options for Inside Turning.

The Radii tab allows you to set a radial containment area for machining. The dialog will change depending on if the Turning Mode (Tool tab parameter) is set to Outside Profiling or Inside Profiling. These parameters are color coded for easy identification.

    Order for Outside Turning.

  • Clearance = Fully retracted safe zone
  • Retract = Above the surface to machine
  • Outer = Actual surface to be machined
  • Inner = Maximum cutting depth

    Order for Inside Turning.

  • Clearance = Fully retracted safe zone
  • Retract = Above the surface to machine
  • Inner = Actual surface to be machined
  • Outer = Maximum cutting depth

Clearance

Shown in Orange, this controls the radius where the tool rapids to at the start and end of the toolpath. For OD machining this position is outside the part. For ID machining this position is from an inside tube or bore. The tool approaches from and retracts to this position.

Shown in Orange, "From" sets the Clearance radius reference position. The reference can be in relation to the Stock, the Model, a specified Radius, Diameter, or any of the other Radial positions. This reference position can be shifted with a positive or negative offset value.

Note: The Clearance radius must be larger than, or equal to, the Retract, the Outer radius and Inner radius to generate a valid toolpath.

Offset

Use this offset to shift the position relative to the Reference point selected above. You can make positive or negative adjustments as needed.

    For Outside Turning.

  • In This Example...
  • Outer = Stock OD (Model + 1mm stock)
  • Retract = Outer + 5mm Offset
  • Clearance = Retract + 5mm Offset

    For Inside Turning.

  • In This Example...
  • Inner = Selected ID Face (Selection)
  • Retract = Inner -.120 In. Offset
  • Clearance = Retract -.260 In. Offset

Retract

Shown in Dark Green, this controls the position above the surface you plan to machine. This is the radius where the tool retracts to between cuts.

Shown in Dark Green, "From" sets the Retract reference position. The reference can be in relation to the Stock, the Model, a specified Radius, Diameter, or any of the other Radial positions. This reference position can be shifted with a positive or negative offset value.

Offset

Same function as the Clearance Offset shown above.

Outer Radius

Shown in Light Blue, this defines the largest radial boundary of the cutting area. For Outside (OD) machining, Outer Radius defines the outer stock surface you plan to machine. For Inside (ID) machining, Outer Radius controls the maximum depth for the cut area.

For Outside Turning.

For Inside Turning.

Shown in Light Blue, "From" sets the Outer Radius reference position. The reference can be in relation to the Stock, the Model, a specified Radius, Diameter, or any of the other Radial positions. This reference position can be shifted with a positive or negative offset value.

Offset

Same function as the Clearance Offset shown above.

Inner Radius

Shown in Dark Blue, this defines the smallest radial boundary of the cutting area. For Outside (OD) machining, Inner Radius controls the maximum depth for the cut area . For Inside (ID) machining, Inner Radius defines the inner stock surface you plan to machine.

For Outside Turning.

For Inside Turning.

Shown in Dark Blue, "From" sets the Inner Radius reference position. The reference can be in relation to the Stock, the Model, a specified Radius, Diameter, or any of the other Radial positions. This reference position can be shifted with a positive or negative offset value.

Same as the Outer Radius "From" options shown above.

Offset

Same function as the Clearance Offset shown above.

Passes tab settings

Tolerance

Also known as the Cut Tolerance, this Tolerance is for toolpath generation and geometry triangulation. Any additional filtering tolerances, like Smoothing, must be added to this tolerance to get the Total Tolerance for the cut..





Loose Tolerance .100

Tight Tolerance .001

CNC machine motion is controlled using G1 line and G2 G3 arc commands. To accommodate this Inventor CAM approximates spline and surface toolpaths by linearizing them; creating many short line segments to approximate the desired shape. How accurately the toolpath matches the desired shape depends largely on the number of lines used. More lines result in a toolpath that more closely approximates the nominal shape of the spline or surface.

Data Starving

A tighter tolerance will result in a more accurate path with smaller line segments. It is tempting to always use very tight tolerances, but there are trade-offs including longer toolpath calculation times, large G-code files and very short line moves. Each can be a problem depending on your situation. Inventor CAM will calculate quickly on almost any computer. But if you have an older NC control with limited memory and a machine with slower axis drives, the toolpath motion might appear jumpy. This is a phenomenon known as data starvation. This Tolerance, along with Smoothing, can reduce your program size and improve your machines performance.

Data starving occurs when the control becomes so overwhelmed with data that it cannot keep up. CNC controls can only process a finite number of lines of code (blocks) per second. That can be as few as 40 blocks/second on older machines and 1,000 blocks/second or more on a newer machines. Short line moves and high feedrates can force the processing rate beyond what the control can handle. When that happens, the machine must pause after each move and wait for the next servo command from the control.

Compensation Type

Specifies the compensation type.

Note: Control compensation (including Wear and Inverse wear) is only done on finishing passes.

Make Sharp Corners

When checked Inventor CAM will force sharp corners in the NC toolpath output. When unchecked (default) Inventor CAM will roll the tool around all sharp corners. This type of motion reduces cycle time, improves surface finish control and allows the machine to flow smoothly between faces.

Caution: Using a smaller tool on the machine can cause a gouge when using this feature.

Finishing Passes

Enable to perform finishing passes. If Roughing is disabled, the Turning Profile toolpath becomes a Finishing Only toolpath. With Roughing & Finishing both enabled, you can rough and finish part with 1 tool.

Both Rough & Finish Passes Enabled.

Finish Pass Enabled. Rough Pass Disabled.

Number of Stepovers

The number of finishing steps.

Stepover

Specifies the stepover distance between passes.

Multiple Finishing Stepovers

Repeat Finishing Pass

When checked this creates 1 additional finishing pass at 0.0 stock. This remove stock left due to tool deflection. Commonly referred to as a Spring Cut

No Drag

When selected, moves that apply negative pressure on the insert are eliminated. Removes cuts up vertical walls and faces within the angle limit shown below. Before reaching the end of the cut, the tool retracts and changes position to cut down the wall

No Drag Limit

Specifies the angle limit that triggers the No Drag behavior. The angle is measured relative to the cutting edge of the tool.

No Drag Clearance and Overlap

No Drag Stop Clearance

No Drag Overlap Distance

Roughing Passes

Enable to perform roughing passes.

Maximum Roughing Stepdown

Specifies the maximum cut stepdowns for roughing.

Maximum Stepdown

Note: Sequential stepdowns are taken at the Maximum stepdown value. The Final Roughing stepdown takes the remaining stock, once the remaining stock is less than the Maximum stepdown value.

Roughing Overlap

Specifies the radial overlap of the roughing passes. A good overlap will insure the surface is smooth for finishing.

Use Back Cutting

For tools with special geometry where chip thinning control is important. This activates additional cutting controls. Only available when the cutting direction is set from Back to Front. See the Tool tab for Mode & Direction.

Starting the toolpath closest to the chuck side, the Radius (R) blends onto the cut and feeds in the positive direction (C). At a distance before the end of the cut (D), the feedrate is reduced to prevent chipping of the part or the tool.

Back Cutting Radius (R) - Consult your tooling supplier for their recommendation on the best Radius blend size. Generally a Radius equal to, or larger than the Maximum Roughing Stepdown will work as a starting point.

Back Cutting Exit Distance (D) Consult your tooling supplier for their recommendation on the best distance and feedrate to use. This uses the Lead-Out Feedrate shown on the Tools Tab.

Use Pecking

Use Pecking creates multiple steps across the length of the cutting direction. Between Pecking Depths the tool retracts along its path by the specified Pecking Retract distance. Use this if your material creates long strings of chips.

Pecking Depths - Specifies the step distance per Peck along the length of the cutting direction. The distance to feed along the cut, between retracts.

Pecking Retract - Specifies the Retract distance between Pecks along the cutting direction.

Tip: To see the points where the tool is pecking and retracting. Go to Simulation and under the Show Toolpath group, enable the Show points icon.

Shown with an 18mm Peck (red arrow) and a 3mm Retract (green arrow)

Stock to Leave

Positive Stock to Leave

The amount of stock left after the operation is completed. This can be removed by subsequent roughing or finishing operations. It's common to leave a small amount of material after a roughing operation.



No Stock to Leave

Remove all excess material up to the selected geometry.



Negative Stock to Leave

Removes material beyond the part surface or boundary.



Radial (OD/ID) Stock to Leave - Axial (face) Stock to Leave

The Radial Stock to Leave parameter controls the amount of material to leave in the radial direction, i.e. Outside Diameter or Inside Diameter. Specifying a positive Radial stock to leave results in material being left on the OD or ID of the part.

The Axial Stock to Leave parameter controls the amount of material to leave in the axial direction (along the Z-axis), i.e. On the faces of flanges. Specifying a positive Axial stock to leave results in material being left on the Faces and shallow areas in the Z direction.

Changing the Radial stock amount automatically sets the Axial stock to the same value. You can manually enter a different Axial stock amount to leave. When using unequal amounts of stock, surfaces that are not exactly horizontal/vertical, Inventor CAM interpolates between the axial and radial stock amounts. So the stock left on these surfaces might be different from the specified value, depending on surface slope.

Axial stock to leave

Radial stock to leave

For finishing operations, it's common to set the default value to 0 mm / 0 in, i.e. no material is left.

For roughing operations, it's common to leave a small amount of material that can then be removed later by one or more finishing operations.

Negative stock to leave

When using a negative stock to leave, the machining operation removes more material from your stock than your model shape. This can be used to machine electrodes with a spark gap, where the size of the spark gap is equal to the negative stock to leave.

Both the radial and axial stock to leave can be negative numbers. However, the negative radial stock to leave must be less than the tool radius. When using a large nose radius or a button type insert with a negative stock, the negative stock must be less than or equal to the radius.

Smoothing

Smooths the toolpath by removing excessive points and fitting arcs where possible within the given filtering tolerance.





Smoothing Off

Smoothing On

Smoothing is used to reduce code size without sacrificing accuracy. Smoothing works by replacing collinear lines with one line and tangent arcs to replace multiple lines in curved areas.

The effects of smoothing can be dramatic. G-code file size may be reduced by as much as 50% or more. The machine will run faster and more smoothly and surface finish improves. The amount of code reduction depends on how well the toolpath lends itself to smoothing. Toolpaths like Parallel and Contour, that lay primarily in a major plane (XY, XZ, YZ), filter well. Those that do not, such as 3D Scallop, are reduced less.

Smoothing Tolerance

Specifies the smoothing filter tolerance. Different than the standard Tolerance (shown above), Smoothing Tolerance is how accurately the linearized points fit together.

If your part profile contains many splines, the spline curve is broken into small linear pieces. Smoothing fits those endpoints together, within the Smoothing Tolerance, to create a contour of blended arcs (G02/G03). Smoothing Tolerance and Tolerance should be combined, to understand the Total Tolerance of the toolpath being generated.

Note: Total Tolerance is the distance the toolpath can stray from the ideal spline or surface shape. It's the sum of the Cut Tolerance and Smoothing Tolerance. For example, setting a cut Tolerance of .0004 in and Smoothing Tolerance of .0004 in means the toolpath can vary from the original spline or surface by as much as .0008 in from the ideal path. For an unequal split, the cut Tolerance should be set higher ( .0006 Cut Tolerance and a .0003 Smooth Tolerance = .0009 Total Tolerance)

Linking tab settings

Retraction Policy

Controls how the tool should retract to the clearance diameter after every cutting pass. or just retract a short distance away from the job. The distance is determined by the Safe Distance value.





Full retraction - completely retracts the tool to the Retract Height at the end of the pass before moving above the start of the next pass. Minimum retraction - moves straight up to the lowest height where the tool clears the workpiece, plus any specified safe distance.

High Feedrate Mode

Specifies when rapid movements should be output as true rapids (G0) and when they should be output as high feedrate movements (G1).

This parameter is usually set to avoid collisions at rapids on machines which perform "dog-leg" movements at rapid.

High Feedrate

The feedrate to use for rapids movements output as G1 instead of G0.

Pull Away Before Retract

Enable to move away from the stock before retracting when possible. By disabling this option, retracts will touch the stock.

Safe Distance

Minimum distance between the tool and the part surfaces during retract moves. The distance is measured after stock to leave has been applied, so if a negative stock to leave is used, special care should be taken to ensure that safe distance is large enough to prevent any collisions.

Approach and Retract

Used to define how the tool should position at the start of the operation and the end of the operation. The default position is in reference to the Safe Z as defined in the Setup. You can override the Setup Safe Z position with the options shown below.

Override Setup Safe Z

Enable to redefine the Reference position for the Safe Z retract.

Safe Z Offset

Set the distance to shift from the reference position specified above.

WCS Reference and Offset Distance

WCS Reference and Offset Distance

Stock Front Reference and Offset Distance

Stock Back Reference and Offset Distance

Lead Mode

The lead mode settings provide very specific control of the leads. There are five options available.

Use Fixed Lead Direction

Specifies that the given lead directions are always relative to the XZ coordinate system. When disabled, the leads are relative to the front/back cutting direction of the individual pass.

Lead-In (Entry)

Enable to generate a lead-in (red arrow) move onto the cut profile.

Lead-in (red arrow)

Lead-In Radius

Specifies the radius of the lead-in move at the start of a cutting pass.



Lead-In Radius @ 0mm

Lead-In Radius @ 3mm

Linear Lead-In Length

Specifies the distance (length) of the lead-in move at the start of a cutting pass.



Linear Lead-In Distance set to 1mm



Linear Lead-In Distance set to 5mm

Lead-In Extension

Specifies the lead-in extension value which has the effect of leading in before the point at which the cutting movement starts by the specified distance.



Lead-In Extension set to 0mm



Lead-In Extension set to 1mm

Linear Lead-In Angle

Specifies the angle of the lead-in move at the start of a cutting pass. Note that the angle reference depends on the Use Fixed Lead direction.



Lead-In Angle @ 45 degrees



Lead-In Angle @ 90 degrees

Lead-Out (Exit)

Enable to generate a lead-out (green arrow) move off of the cut profile.

Lead-out (green arrow)

Same as Lead-In

Specifies that the lead-out definition should be identical to the lead-in definition.

Linear Lead-Out Distance

Specifies the distance (length) of the lead-out move at the end of a cutting pass.



Linear Lead-Out Distance set to 1 mm



Linear Lead-Out Distance set to 5 mm

Lead-Out Extension

This setting has the effect of delaying the point at which the cutter begins to lead out by the specified distance.



Lead-Out Extension set to 0mm

Lead-Out Extension set to 1mm

Lead-Out Radius

Specifies the radius of the lead-out move at the end of a cutting pass.



Lead-Out Radius @ 0mm

Lead-Out Radius @ 3mm

Linear Lead-Out Angle

Specifies the angle of the lead-out move at the end of a cutting pass. Note that the angle reference depends on the Use Fixed Lead direction.



Lead-Out Angle @ 45 degrees



Lead-Out Angle @ 90 degrees