CHAPTER 9: TROUBLESHOOTING / MAINTENANCE 91
TRYTON 107/112
1. FACTORS AFFECTING PERFORMANCE
1.1. Installation
The installation is a very important phase that, if neglected, could seriously impede the operation of the bar
feed system.
1.2. Distance
The distance between the bar feed system and the lathe influences greatly the quality of the guiding. The
further the bar feed system is from the spindle -- and therefore, away from the clamping system -- the larger
the non-guided part of the bar will be.
It is essential that the mounting of the bar feed system is done in accordance with the instructions indicated
in Chapter 3: Setting into operation.
1.3. Alignment
Although the bar rotates in an oil bath inside the barrel, the guidance tube must be perfectly aligned on the
spindle axis.
It is essential that the alignment of the bar feed system is done in accordance with the instructions indicated
in Chapter 3: Setting into operation.
1.4. Spindle length
In some cases, the length of the spindle may influence the quality of the guidance.
1.5. Clearance between the channel and the bar
The best results are obtained when the bar is guided with precision (2 mm). The greater the reduction of
the clearance between the bar and the tube, the greater the rotation speeds will be.
When the clearance between the bar and the tube becomes too great, a rupture of the oil film occurs which
results in the reduction of the rotation speeds permitted.
1.6. Clearance between the spindle and the bar
While the rear of the bar is maintained by front rest of the bar feed system and the front by the collet or the
chuck of the lathe, it is possible for the portion of the bar inside the spindle to oscillate, if the clearance is
too great.
It is, therefore, highly recommended to install reduction liner inside the spindle.
1.7. Bars
To obtain a perfect insertion inside the collet of the bar feed system, the bars must be chamfered
concentrically (at the rear) at 30o. At the feeding process, it is recommended to deburr the bar at the front,
to avoid possible catching during the introduction of the bar inside the spindle.
1.8. Tubes
To prevent mixing the oil from the feeding process and the cutting oil from the lathe, it is recommended to
put a plug in the rear of the tubes to be machined.
1.9. Straightness of the bars
Performances may vary, depending on the material machined, the length of the bar, etc.
To obtain optimum output, the bars must be straight.
If the torsion of the bars exceeds 0.5 mm/m, performance will automatically be reduced in regards to speeds
of rotation while vibrations will increase accordingly.
In this instance, the quality of the guidance is not the cause.
1.10. Composition of the material
In general, the difficulty increases with the specific weight of the bar.
Steel bars are relatively easy to guide.
Because of their great flexibility and specific weight, brass bars are relatively difficult to guide at high
speeds.
Aluminum bars of aluminum are very easy to guide.
To Next Page
Loading...
