Introduction

The purpose of this tutorial is to demonstrate how to set up work offsets on your Pocket NC V2-10 or V2-50 when the A and B axis are both at 0°. We highly recommend this method, however if your part requires work offsets to be set with A or B axis at a position other than 0°, reach out to Penta Machine Co. for an alternate procedure.

This tutorial refers to the Kinetic Control user interface released on 11/1/2021 but the entire process can be performed using the older “Legacy” user interface as long as simultaneous 5-axis toolpaths are not needed.

A spreadsheet that simplifies calculating work offsets can be downloaded below, along with a video showing this process as it was used in our Pocket NC 101 course.

Setting Work Offsets

Once the machine knows where the physical work coordinate system (WCS) origin is located on the stock, it can then accurately cut a part from the stock loaded in the machine. A very common location for the WCS origin is the front, top corner facing the spindle, so that is what will be used as an example in this tutorial.

NOTE: The physical WCS origin that gets set by defining/setting work offsets must match the WCS origin that has been defined in the CAM software being used to generate the g-code.

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There are several ways to locate the origin but in this example we are going to use the simple touch-off method.

Measure and Select an Active Tool

Before you begin, measure the tool that will be used for this program on the “Setup” tab of the User Interface (UI). With the tool measured, we want to make sure that it is active. Under the “Work Offsets” section at the top of the Setup tab, the tool you are using and just measured should be listed as active and the tool length offset should be listed below it. Click here to refer to the “Tool Offsets” section in the Kinetic Control and how to use the automatic tool measurement probe and how to select an active tool.

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Verify that JOG MODE is set to “Joint”

Kinetic Control defaults its “JOG MODE” to “Joint”. In “Joint” jog mode, the machine only moves the corresponding axis' individual motor when jogging. The other “JOG MODE” is “Axis”. “Axis” jog mode does not necessarily mean that the axes are aligned with the machine motors, for example, when the machine is in TCPC (Tool Center Point Control) mode. It is possible that more that one axis motor might move when in “Axis” jog mode. If you jog only one axis and notice multiple DRO values changing simultaneously, then your machine is set to “Axis” jog mode.

Navigate to the “Manual” tab and click the three bar menu under the “Jog” heading.

Verify that “JOG MODE” is set to “Joint”.

Setting the X Work Offset

• Use the jogging controls in the Kinetic Control user interface to position the touch-off tool in front of the stock and just below the top of the stock, using .01” steps. Be careful to avoid colliding the tool with the stock. Once the tool is as close to the stock as it can be using .01” steps, switch to .001” steps and continue to move the tool in the X positive direction until the tool just touches the surface of the stock.

• Set the X work offset by clicking the three bars in the X value in the G5x column. A pop-up window will appear that allows you to set the desired X position of the tool. In this case, negative the radius of the tool.

• Since we want to find the true location of this side, using the center axis of the tool, we will need to enter a value to account for the radius of our tool (the centerline of our tool is currently a tool-radius’s distance from the edge of the stock). For a 1/8” diameter tool, enter a value of -0.0625 (in.) to account for the tool radius because that is how far the center of the tool is offset from the face of the stock in the negative direction and click the “Set” button.

• The X Work Offset = X DRO Value - (Negative Radius of the Tool) = -1.4500 - (-0.0625) = -1.3875 in.

• Notice that now Kinetic Control’s X DRO measures a negative tool radius distance from the X Work Coordinate origin point located on the stock.

Setting the Y Work Offset

• Use the jogging controls in the Kinetic Control user interface to position the touch-off tool on the top, front corner of the stock, using .01” steps. Be careful to avoid colliding the tool with the stock. Once the tool is as close to the stock as it can be using .01” steps, switch to .001” steps and continue to move the tool in the Y negative direction until the tool just touches the surface of the stock.

• Set the Y work offset by clicking the three bars in the Y value in the G5x column. A pop-up window will appear that allows you to set the desired Y position of the tool. In this case, positive the radius of the tool.

• Since we want to find the true location of the top of the stock, using the center axis of the tool, we will need to enter a value to account for the radius of our tool (the centerline of our tool is currently a tool-radius’s distance from the top of the stock). For a 1/8” diameter tool, enter a value of +0.0625 (in.) to account for the tool radius because that is how far the center of the tool is offset from the top of the stock in the positive direction and click the “Set” button.

• The Y Work Offset = Y DRO Value - (Positive Radius of the Tool) = 1.8100 - (+0.0625) = 1.7475 in.

• Notice that now Kinetic Control’s Y DRO measures a positive tool radius distance from the Y work coordinate origin point located on the stock.

Setting the Z Work Offset

• Use the jogging controls in the Kinetic Control user interface to position the touch-off tool on the right, top corner of the stock, using .01” steps. Be careful to avoid colliding the tool with the stock. Once the tool is as close to the stock as it can be using .01” steps, switch to .001” steps and continue to move the tool in the Z negative direction until the tool just touches the surface of the stock.

• Set the Z work offset by clicking the three bars in the Z value in the G5x column. A pop-up window will appear that allows you to set the value for distance the center of the tool is away from the Z touch off point.

• Since the tip of the tool rests directly on the desired Z location of the right face of the stock, enter a value of 0.000 (in.) and click the “Set” button.

• The Z Work Offset = Z DRO Value = 1.0500 in.

• Notice that now Kinetic Control’s Z DRO is exactly at the zero point of the Z work coordinate origin point located on the stock.

Summary

In the example above, the G54 work offsets were used to store the location of the origin of the stock loaded on the Pocket NC. In this case, the stock’s origin is -1.3875” away in the X direction, 1.7475” in the Y direction, and 1.0500” in the Z direction from the machine’s center of rotation. Kinetic Control will now use the G54 work offset information to translate the work coordinate system relative to the location of stock instead of the machine’s center of rotation.

Below are tables of formulae to calculate work offsets when A=0°. The X, Y, and Z DRO values are those measured at the touch points.

Work Offset Formulae for A=0°

Download the Pocket NC V2 Work Offset Calculator Spreadsheet for A=0° and A=90°.

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