OMAX JetMachining® Center Operator’s Guide
Maintenance
4 - 50
400433D-EN
The standoff between the abrasivejet
nozzle and the material is excessive.
The standoff should be no more than 0.050" (1.3 mm) for best results.
Note:
0.060" (1.52 mm) is generally recommended, especially with
the Tilt-A-Jet option. Typically, lower standoff distances
decrease the amount of taper, but a lower standoff increase
the likelihood of nozzle plugging. The pierce and cut heights
can be set at different heights using Motion Preferences in
Make.
Setup values in Make are not
consistent with the actual physical
requirements.
Check that the material setup values for the following parameters are
correctly set in Make:
• Machinability —
Thickness
Click
Setup
in Make, choose
Pump and Nozzle settings
, and verify
that values for the following parameters are set correctly:
• Water pressure
• Orifice diameter
• Mixing tube diameter
• Abrasive flow rate
•
An abrasive other than the
recommended garnet is being used.
Many abrasives do not cut as well as garnet, and the machinability should
be reduced when using these abrasives. It may be necessary to
experiment to determine the best settings.
Garnet is recommended because it allows a good cutting rate with
relatively low mixing tube wear. Garnet is also nonhazardous and, as such,
is easily disposed. Other abrasives may increase mixing tube wear and
may be a disposal hazard.
WARNING!
Never use silica sand as a cutting abrasive. Fine silica
dust produced by the cutting process can lead to
silicosis, a serious lung disease.
The mixing tube is worn and unable to
form a perfect jet stream
Mixing tube wear occurs first at the inlet, then a conical wear zone grows
toward the exit end of the mixing tube. Check the tube bore at both ends
using a drill or gage pin. When the outlet has increased in diameter by
0.005" (0.13 mm), the mixing tube is near the end of its useful life for
precise cutting.
The jewel that forms the jet is chipped,
dirty or out of tolerance.
Replace the jewel and the jewel holder.
Holes are Not Round
Condition and Possible Causes
Corrective Action
The cutting material is not securely
fixtured.
The material was able to move during the cutting process due to drag of
the nozzle or upwelling of the water below. Ensure that the material being
cut is securely fixtured. This is the most common reason for scraped parts.
The jet is elliptical rather than round
due to wear in the mixing tube or a
slightly imperfect orifice.
Change the orifice first. If the jet remains elliptical, change the mixing tube.
Summary of Contents for JetMachining Center 2626
Page 8: ...OMAX JetMachining Center Operator s Guide viii 400433D EN ...
Page 12: ...OMAX JetMachining Center Operator s Guide xii 400433D EN ...
Page 22: ...OMAX JetMachining Center Operator s Guide Safety First 1 10 400433D EN ...
Page 140: ...OMAX JetMachining Center Operator s Guide OMAX Glossary 6 16 400433D EN ...
Page 144: ...OMAX JetMachining Center Operator s Guide Index 4 400433D EN ...