Specifications

Southwestern Industries, Inc.
ProtoTRAK SMX K2, K3, K4 & Retrofit Safety, Installation, Maintenance, Service & Parts List Manual
59
4.1.4.1 Spindle Speeds
Spindle speeds are influenced by a number of variables:
• Material
• Rigidity of the Machine Setup
• Coolant
• Cutter type, material and diameter
• Cutting Depth
As a general rule:
• Lower spindle speeds are used to machine hard or tough material or where heavy cuts
are taken.
• Higher spindle speeds are used to machine softer materials in order to achieve better
surface finishes. Higher speeds also apply when using small diameter cutters for light
cuts on frail work pieces and delicate setups.
Note: Cutter diameter greatly affects spindle speeds. The larger the diameter, the lower the spindle speed.
4.1.4.2 Feedrates
Factors that affect feedrates:
• Depth and width of cut
• Design or type of cutter
• Sharpness of the cutter
• Workpiece material
• Type of finish or accuracy required
• Climb or conventional milling
If a fine finish is required, reduce the feed rather than increase the spindle speed. Cutters
are dulled by higher spindle speeds rather than high feedrates.
4.2 The Mechanical Drive Train (X, Y)
Indications:
• Troubleshooting instructions indicate that the drive train is potentially the problem and
other (more easily checked variables) have been exhausted.
• Roughness, looseness, tightness or jamming movement in the table or saddle.
1. Check for machine considerations, especially gib locks and gib adjustments.
See Gib Adjustments section
2. Check the torque of the axis in three places (both ends and center of ball screw) along
the length of the ball screw. The torque should be within 2 or 3 in-lbs across the length
of the ball screw. If it is not, chances are the ball screw is misaligned. A misaligned ball
screw can lead to parts being out of round and servo problems at low feedrates. A bad
ball screw can also cause high torque, although this is highly unlikely. See Sections 4.2.1
and 4.2.2 for more information.