Tormach PCNC 770 - Page 204

Chapter 10
204
UM10350_PCNC770_Manual_0916A
Troubleshooting
• The wrong diameter tool used in the CAM program (i.e., many 1/2” end mills are not
actually .500”)
• Mill referencing to the part was performed improperly and/or relying on the end of travel
limit switches to set mill osets
• Fixturing does not secure work, or does not facilitate repeatable mounng of work from one
piece to the next
These are what we call process errors, and have lile to do with a problem residing with the mill itself.
The scope of this poron of the troubleshoong guide does not cover soluons to process errors.
It is imperave to divide a given setup into manageable porons so one can focus on where the
problem really lies. Is it a process problem, or is it a mill problem? In order to isolate mill problems
from process problems, the process must be removed from the setup.
Moon Test
The goal of this test is to measure mill moon explicitly, thus eliminang process-based problems.
In this instance, the X-axis is checked, but a similar process can be used on the Y- and Z-axis as well:
1. Be sure that G40 and G49 show up in the modals list at the top of the screen.
2. Mount a quality dial indicator on the mill bed, orienng the plunger along the X-axis. Place it
near the end of travel.
3. Orienng the axis such that the indicator plunger contacts an appropriate surface on the
spindle head, move the X-axis such that the indicator is zeroed, then zero the X-axis DRO.
4. Aer moving the spindle head away from the indicator, proceed with exercising the axis: using
manual moves, or a very simple G-code program, move the axis at varying speeds (parcularly
focus on rapid speed). The more steps you run the axis through, the higher the probability
that a step is missed if there is a mill problem.
5. Return the axis to indicator zero, and
read what the DRO says. Allowing
for some lost moon (about .001”),
the value indicated on the DRO
should be 0. If not, then the mill is
missing steps.
The Z-axis brake has a manual release (see
Figure 10.13) to disengage the brake. It is
not recommended to run your mill in the
disengaged posion.
Figure 10.13
Engaged
(normal
mode)
Disengaged
(maintenance
mode)