Tormach PCNC 770 - Setting Work Offset by Touching Off Workpiece

Chapter 5
46
UM10350_PCNC770_Manual_0916A
Intro to PathPilot
Tool Osets
Tool osets allow the operator to use tools of dierent length and (in the case of cuer radius
compensaon) dierent diameters. In the program you will create during this tutorial, you will use
two dierent tools. Because it is extremely unlikely that these tools will be exactly the same length,
the control needs to account for the dierence in tool length when switching tools.
If you measure your tools when you put them in TTS holders, then the PathPilot operang system
allows you to switch tools quickly and without the need to do anything more when you run a program
using them. Each tool and its holder only needs to be measured once, either oine or on the mill.
Once a tool has been measured, the tool length oset must sll be applied. Tool length osets are
not applied automacally – on virtually all CNC milling machines the tool length oset is applied
with the G43 command. When running a G-code program, the G43 G-code command must be called
out to apply a tool length oset – tool osets will not be applied with just a tool change command.
While operang manually, the M6 G43 buon does this for you. The code you generate using the
Conversaonal screens later in this tutorial will include the G43 command in the appropriate place
in the G-code. Use of cuer compensaon (G41/42) is a more advanced topic which is covered in
chapter 7, Programming.
5.1.4.1 Setting Work Offset by Touching Off Workpiece
There are many ways of conceptualizing tool and work
osets, but we use the idea of a true posive tool length
to demonstrate this rst part program. When using this
method we will touch the face of the spindle to the top of
the workpiece to set the work Z zero (see Figure 5.4). If you
set your work Z zero using the face of the empty spindle then
touch your tools o to the same work zero, the tool length
osets are equal in value to the length of the tool. True
posive tool length has a few benets over other methods
(e.g., relave tool lengths) of measuring tool osets:
• You can easily look at the tool length oset value
and esmate whether it is correct for a given tool by
checking that tool with a ruler or calipers.
• You can mix tools that have been touched o on the
mill with tools that have been measured using a digital
height gauge.
• It is conceptually easier to understand than the
alternaves.
Seng the Z Work Oset
1. If a tool is in the spindle, remove the tool from the spindle.
Figure 5.4