Dalian Haisen Machinery Co.,Ltd

CNC Lathe Limit Setting To Distinguish

Jan 25, 2019

      In order to ensure the safety of the operation of CNC lathes, both ends of each straight axis are limited.The limit of CNC lathe can be divided into soft limit, hard limit and mechanical hard limit.

      1. Hard limit

    In the positive and negative limit positions of the servo shaft, limit switches or proximity switches are installed, which is the so-called hard limit.The hard limit is the last protection of the servo shaft movement beyond the limit, the more hard limit after a very short distance to reach the mechanical hard limit.Due to the high power of the servo system, once it hits the mechanical hard limit, it may cause damage to the parts, which is not allowed.Therefore, the hard limit switch action results in an emergency shutdown.When the feed axis moves beyond the stroke of the machine tool, the limit of the machine tool will play a role, the machine tool alarm, resulting in manual or hand wheel operation when the corresponding coordinate axis can not continue to move;When automatic machining, all axes will stop machining.At this time, we think the CNC lathe is a limit fault.

      2. Soft limit

    The soft limit of the servo shaft is the range of motion of the shaft set by the machine tool parameters (1320 and 1321 belong to the shaft parameters) with the machine tool reference point as the reference point.If you go beyond that, you're going over the soft limit.Soft limit has no limit switch and is only a set of position coordinates.

      3. Setting of soft limit parameters 1320 and 1321

      (1)Reset CNC lathe;

     (2) Manually move the coordinate axis to reach the soft limit set as expected, and record the coordinate value of the machine tool;

      (3 )Write the coordinate value into the parameter, note that the unit is micron.

      FANUC: parameters P1320 and P1321 (in micron units);

      SIMENS: 36100 and 36110;

      GSK: 45-48 parameter (see Chinese hint).

      Soft limit parameters can only be modified after the parameters are unlocked!

      4.CNC lathe limit lifting

      In order to remove the limit fault, it is necessary to distinguish which kind of fault belongs to, namely, soft limit or hard limit.The distinguishing method is alarm message or observation feed shaft position.

    (1)Soft limit lifting: in general, as long as the overshoot axial overshoot in the opposite direction to move out of the overshoot area, press the reset button to eliminate the alarm and the machine tool returns to normal.

    (2)Lifting of hard limit: it is generally required to move in the opposite direction while holding down the "overpass release" (" overpass release ") on the machine tool.If the machine tool does not release the button, you need to try to reverse the steering wheel screw.

      Note: press the emergency stop button at this time, otherwise the electrical lock.


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