About Turning Chamfer



Access:

Ribbon: CAM tab Turning panel Chamfer

The Chamfer strategy is used for chamfering sharp corners that have not been chamfered in the design.

Tool tab settings



Coolant:

The type of coolant used with the tool.

Use tailstock

A tailstock is used to apply support to the longitudinal rotary axis of the workpiece being machined. This is particularly useful when the workpiece is relatively long and slender. Failing to use a tailstock can cause the workpiece to bend excessively while being cut and cause "chatter".

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 machine needs.

Once configured, you would typically see M21 (tailstock forward) at the beginning of the operation and M22 (tailstock backward) at the end with this option enabled.

Go home:

The Home position is a known Z value relative to the WCS and is defined within the Work Coordinate System (WCS) section on the Setup tab of the Setup strategy dialog.

You can force the tool to move to the Home position prior to starting the operation, or once the operation has finished. The tool will always pull out of the stock in the X axis until it reaches the Clearance height, then move to the Home position in the Z.

Mode:

Depending on the turning strategy, this setting determines whether the tool machines axially or radially as well as the approach/retract direction.

Tool orientation:

Use this option if your lathe turret has a programmable B axis. Your post processor will need to support posting from this value.



Tool orientation @ 45 degrees

Tool orientation @ 90 degrees

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 HSM Help topic:About Turning Feeds & Speeds.

Spindle speed:

The rotational speed of the spindle.

Surface speed:

The spindle speed expressed as the speed of the tool on the surface.

Maximum spindle speed:

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

Use feed per revolution

Enable to automatically adjust the feedrate based on the RPM of the spindle to maintain a constant chip speed.

Cutting feedrate:

Feed used in cutting moves.

Lead-in feedrate:

Feed used when leading in to a cutting move.

Lead-out feedrate:

Feed used when leading out from a cutting move.

Geometry tab settings



Chamfers

Use the Chamfers selection button to select one or more circular edges for chamfer creation.

Radii tab settings



Clearance

Set this height to control the radius where the tool enters and exits the toolpath. The tool approaches and retracts from inside the stock along the Z axis (spindle axis) at this radial clearance offset. The value displayed on the orange tab represents its current radius relative to the setup axis.



Outer Clearance Radius

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

Clearance offset:

Specifies the clearance offset value.



Outer Clearance Offset

Outer Radius

Defines the radial confinement by limiting the outer radial range of the toolpath. You can choose from the following:



Outer Radius

Outer radius offset:

Specifies the outer radius offset value.

Inner Radius

Defines the radial confinement by limiting the inner radial range of the toolpath. You can choose from the following:



Inner Radius

Inner radius offset:

Specifies the inner radius offset value.

Passes tab settings



Tolerance:

The machining tolerance is the sum of the tolerances used for toolpath generation and geometry triangulation. Any additional filtering tolerances must be added to this tolerance to get the total tolerance.



Loose Tolerance .100



Tight Tolerance .001

CNC machine contouring motion is controlled using line G1 and arc G2 G3 commands. To accommodate this, 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

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. The first two are not much of a problem because Inventor HSM calculates very quickly and most modern controls have at least 1MB of RAM. However, short line moves, coupled with high feedrates, may result in a phenomenon known as data starving.

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 machine like the Haas Automation control. 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.

Chamfer width:

The (additional) width of the chamfer. For edges that are not already chamfered, this is the final width of the chamfer.

For chamfered edges, this is an additional offset, similar to using negative radial stock to leave.

Chamfer extension:

Distance by which to extend the chamfer cutting pass.

Chamfer angle:

The angle of the chamfer measured from the Z-axis.

Stock to Leave



Positive

Positive Stock to Leave - The amount of stock left after an operation to be removed by subsequent roughing or finishing operations. For roughing operations, the default is to leave a small amount of material.



None

No Stock to Leave - Remove all excess material up to the selected geometry.



Negative

Negative Stock to Leave - Removes material beyond the part surface or boundary.

Radial (wall) stock to leave:

The Radial stock to leave parameter controls the amount of material to leave in the radial (perpendicular to the tool axis) direction, i.e. at the side of the tool.



Radial stock to leave



Radial and axial stock to leave

Specifying a positive radial stock to leave results in material being left on the vertical walls and steep areas of the part.

For surfaces that are not exactly vertical, Inventor HSM interpolates between the axial (floor) and radial stock to leave values, so the stock left in the radial direction on these surfaces might be different from the specified value, depending on surface slope and the axial stock to leave value.

Changing the radial stock to leave automatically sets the axial stock to leave to the same amount, unless you manually enter the axial stock to leave.

For finishing operations, the default value is 0 mm / 0 in, i.e. no material is left.

For roughing operations, the default is 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 ball or radius cutter with a negative radial stock to leave that is greater than the corner radius, the negative axial stock to leave must be less than or equal to the corner radius.

Axial (floor) stock to leave:

The Axial stock to leave parameter controls the amount of material to leave in the axial (along the Z-axis) direction, i.e. at the end of the tool.



Axial stock to leave



Both radial and axial stock to leave

Specifying a positive axial stock to leave results in material being left on the shallow areas of the part.

For surfaces that are not exactly horizontal, Inventor HSM interpolates between the axial and radial (wall) stock to leave values, so the stock left in the axial direction on these surfaces might be different from the specified value depending on surface slope and the radial stock to leave value.

Changing the radial stock to leave automatically sets the axial stock to leave to the same amount, unless you manually enter the axial stock to leave.

For finishing operations, the default value is 0 mm / 0 in, i.e. no material is left.

For roughing operations, the default is 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, when using a ball or radius cutter with a negative radial stock to leave that is greater than the corner radius, the negative axial stock to leave must be less than or equal to the corner radius.

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.

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.

Parent topic: About Turning