Specifications

Southwestern Industries, Inc.
ProtoTRAK SMX K2, K3, K4 & Retrofit Safety, Installation, Maintenance, Service & Parts List Manual
61
Potential Problem:
Check By:
Ball nut not tightened to
the yoke
• Inspection for space between the head of the bolt and the ball nut i.e.
the retaining bolt has bottomed out in its thread and is not securing the
ball nut to the yoke properly.
Yoke loose in the saddle • Inspection for any motion of the yoke or looseness in the Yoke
mounting screws.
Oil lines sheared
•
Visual inspection.
Oil line blockage • Pump the oil and ensure that it flows evenly to the ways and ball
screw.
Ball screws not aligned
properly
• Measure from the ball screw to the back of the saddle on both sides of
the yoke (the table must be removed). The measurements must be
within ±.005” end to end. See above explanations.
Note: Ball screws are inspected throughout their entire travel for backlash and consistent torque. A
ball screw should be good for millions of inches of travel if installed properly. Do not be too quick to
replace a ball screw if there is insufficient indication that it is bad; this will just be a costly delay to
resolving the real problem.
4.2.1 Keys to Ball Screw Alignment
• X-axis – there are 3 components that can cause misalignment: the yoke, the left side
bearing housing bracket, and the right side bearing housing.
• Yoke – the yoke is aligned at the factory and pinned in place. It is aligned to within
+/-0.0005” with a precise alignment tool. The yoke most likely is not causing the
problem. If this were the problem you would need to remove the pins and align the X
ball screw with the back of the saddle. Drill new holes and pin the yoke in place. The Y-
axis ball screw bore is machined perpendicular to the X bore. If the X-axis is aligned the
Y-axis will also be aligned.
• Left side table bearing housing – this is most likely the cause of the misalignment.
To align the bracket and bearing housing, move them as close to the yoke as possible.
Loosen the bracket bolts and bearing housing bolts and then retighten. This should allow
the bearing housing to align itself up with the yoke.
• Right side table bearing housing – once again move the bearing housing as close to
the yoke as possible. Loosen the bearing housing and retighten. This should allow the
bracket to align itself. If you do not move the table toward the yoke the ball screw will
tend to bend down slightly and cause misalignment.
• Y-axis – the only component that can cause a misalignment problem is the motor
mounting bracket. To align this bracket, move the saddle as close to the front of the
machine as possible. Loosen the bracket and then retighten it. Once again moving the
saddle forward allows the yoke to be as close to the bearing housing as possible.
4.3 Computer/Pendant Diagnostics
The pendant consists of 2 separate modules: the computer module, and LCD
screen/enclosure.
In general, the pendant/computer module is best diagnosed by eliminating all other possible
alternatives. The following table lists some problems and what these problems can lead to.