Spindle functions

Spindle functions

Function

Spindle modes are:

• Open-loop control mode, constant spindle speed S or constant cutting rate G96
• Oscillation mode
• Positioning mode
• Synchronous mode (synchronous spindle)
• Thread cutting/tapping functions of spindle modes:
• Spindle speed with spindle override
• Five gear stages, specified in the
  • part program (commands M41 to M45)
  • automatically via programmed spindle speed M40 or
  • PLC function block FC18
• Oriented spindle stop (positioning mode) with SPOS¹⁾
• Spindle monitoring with the functions¹⁾:
  • Axis/spindle stationary (n < n_min)
  • Spindle in setpoint range
  • Spindle speed, max.
  • Programmable lower (G25) and upper (G26) spindle speed limitation
  • Speed of the gear stage minimal/maximum
  • Maximum encoder limit frequency
  • End point monitoring for SPOS
• Constant cutting speed with G96 (in m/min or inch/min) at the tool tip for uniform surface finish and thus better surface quality.
• Spindle control via PLC for oscillation (so that it is easier to engage a new gear stage) and positioning
• Changeover to axis mode:
  For machining with a position-controlled spindle (e.g. face machining of turned parts), the main spindle drive can be switched to the axis mode using a program command. A common encoder can be used for both axis and spindle modes. The zero mark of the spindle is also the reference mark of the C axis, so there is no longer any need to home the C axis (synchronize C axis on the fly).
• Thread cutting with constant pitch¹⁾:
  The following thread types can be produced with G33: cylindrical, taper and face thread, single-start or multiple-start, as left-hand or right-hand thread. In addition, multiple-block threads can be produced by concatenating threading blocks.
• Thread cutting with variable lead¹⁾:
  Threads can also be programmed with linearly progressive (G34) or linearly degressive (G35) lead.
• Programmable thread run-in and run-out path:
  When thread cutting, DITS/DITE (displacement thread start/end) can be used to program the path ramp for the acceleration or deceleration process as a distance. This makes it possible, for example, to adjust the acceleration on the thread shoulder when the tool run-in or run-out is too short and initiate smoothing at the next CNC start.
• Tapping with compensating chuck/rigid tapping:
  When tapping with compensating chuck (G63), the compensating chuck equalizes differences between spindle movement and drilling axis. A prerequisite for rigid tapping (G331/G332) is a position-controlled spindle with position measuring system. The traversing range of the drilling axis is therefore not restricted. By using the method where the spindle, as a rotary axis, and the drilling axis interpolate, threads can be cut to a precise final drilling depth, e.g. for blind hole threads.

Benefits

• Spindle monitoring facilitates the diagnosis of faults·
• Uniform surface finish and thus better surface quality as a result of constant cutting speed at the tool cutting edge
• Fast switchover between axis/spindle mode without referencing
• Machining of cylindrical, taper and face threads, single-start or multiple-start, as left-hand or right-hand thread. In addition, multiple-block threads can be produced by concatenating threading blocks and rigid tapping is possible.

¹⁾ Prerequisite: actual-position sensor (measuring system) with corresponding resolution (mounted directly on the spindle).