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ForumCSMIO/IP controllers and Software - discussion forum: CSMIO/IP with simCNC softwareHelp with setup Backlash compensa …

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Help with setup Backlash compensation

#1 · 18 February 2026, 13:18

Quote from Vladislav on 18 February 2026, 13:18
Hello everyone.
I have an old Almac 5-axis machine. The standard NUM760 CNC system lost its configuration, so I decided to upgrade to a CSMIO IP-A. The machine has Indramat analog drives, Heidenhain LS403 linear encoders, and Heidenhain ROD 1451 rotary encoders, which are paired with Heidenhain EXE signal converters that output TTL. There are no issues with the electronics; I assembled everything, connected it, and it works, but I have a problem I can't solve yet. The problem is that there's play between the lead screw and the nut of the linear axes (XYZ), approximately 0.01-0.02 mm, and I need to somehow adjust the play compensation. The machine currently works like this: I move the axis in one direction when the backlash is removed, the coordinates on the CNC (monitor) move synchronously with the dial gauge (with a division value of 0.001). The axis then stops, and the coordinates on the CNC screen and dial gauge also stop. I then move the axis in the opposite direction, and the coordinates on the monitor change, but not on the dial gauge. After moving approximately 0.014-0.015 mm on the monitor, the axis jerks 0.007-0.008 mm according to the gauge, meaning the backlash is removed, but not completely. The question is how to force the machine to move the axis immediately by the entire backlash amount, or to force it to rely solely on the encoders, as larger racks do (the CNC immediately makes an adjustment at the slightest deviation in the encoder position). Let me say right away that I understand that relying solely on the CNC system to solve a mechanical problem in a machine is wrong, but unfortunately, there's no way to fix it right now, and I'd like to get the machine working more or less acceptably. I understand there will be some vibrations in the mechanics when moving, but I'm willing to live with that. If there's a necessary option in the settings, I'd be grateful for a hint where and how to click it, or perhaps something needs to be changed in the configuration. I'm not new to CNCs; I have experience working with and programming Fanuc, Siemens, and Mitsubishi control systems. I also have experience assembling, configuring, and writing macros for Mach3 machines and various Chinese controllers like DDCS.

Hello everyone.
I have an old Almac 5-axis machine. The standard NUM760 CNC system lost its configuration, so I decided to upgrade to a CSMIO IP-A. The machine has Indramat analog drives, Heidenhain LS403 linear encoders, and Heidenhain ROD 1451 rotary encoders, which are paired with Heidenhain EXE signal converters that output TTL. There are no issues with the electronics; I assembled everything, connected it, and it works, but I have a problem I can't solve yet. The problem is that there's play between the lead screw and the nut of the linear axes (XYZ), approximately 0.01-0.02 mm, and I need to somehow adjust the play compensation. The machine currently works like this: I move the axis in one direction when the backlash is removed, the coordinates on the CNC (monitor) move synchronously with the dial gauge (with a division value of 0.001). The axis then stops, and the coordinates on the CNC screen and dial gauge also stop. I then move the axis in the opposite direction, and the coordinates on the monitor change, but not on the dial gauge. After moving approximately 0.014-0.015 mm on the monitor, the axis jerks 0.007-0.008 mm according to the gauge, meaning the backlash is removed, but not completely. The question is how to force the machine to move the axis immediately by the entire backlash amount, or to force it to rely solely on the encoders, as larger racks do (the CNC immediately makes an adjustment at the slightest deviation in the encoder position). Let me say right away that I understand that relying solely on the CNC system to solve a mechanical problem in a machine is wrong, but unfortunately, there's no way to fix it right now, and I'd like to get the machine working more or less acceptably. I understand there will be some vibrations in the mechanics when moving, but I'm willing to live with that. If there's a necessary option in the settings, I'd be grateful for a hint where and how to click it, or perhaps something needs to be changed in the configuration. I'm not new to CNCs; I have experience working with and programming Fanuc, Siemens, and Mitsubishi control systems. I also have experience assembling, configuring, and writing macros for Mach3 machines and various Chinese controllers like DDCS.