Backlash Compensation

Semi-assembled (v3) LumenPnP machines should have only a limited amount of backlash in each axis and the default machine configuration in OpenPnP will typically account for it. This step is optional, and only necessary if you are still having issues with backlash. Read the OpenPnP docs page about automatic backlash compensation here.

Set Up Acceleration Control

1. Click on the Machine Setup tab in the top right pane.

2. Click on the "Expand" checkbox if necessary.

3. Select GcodeDriver GcodeDriver from the list.

4. Switch to the gcode tab.

5. Select MOVE_TO_COMMAND in the setting drop-down.

6. Paste the following into the large text box:

   {Acceleration:M204 S%.2f} G1 {X:X%.4f} {Y:Y%.4f} {Z:Z%.4f} {A:A%.4f} {B:B%.4f} {FeedRate:F%.2f} ; move to target

7. Click Apply to save your changes.

8. Switch to the Driver Settings tab.

9. Change the Motion Control Type to ConstantAcceleration. Note that you may want to change this back to ToolpathFeedRate when you're done running the backlash calibration.

10. Click Apply to save your changes.

Running The Calibration

1. Click on the Machine Setup tab in the top right pane.

2. Click on the "Expand" if necessary.

3. Click on Axes > ReferenceControllerAxisX.

4. Select the Backlash Compensation tab.

5. Next, click the Calibrate now button. The machine will go through a long routine (between 5-15 minutes) where it measures the machine's backlash, and determines the best settings to account for it.

6. When it's done, you'll see the output data from the calibration. We suggest selecting OneSidedPositioning for the Compensation Method, but experiment with the different options to see which gives you the best results.

7. Restart from step 10 with the Y axis selected.

Next Steps

Next is Automatic Toolchanger Calibration.