If the 3D printing module pushes into the print sheet during the Calibration or Printing, please refer to the following tips to have a check. 

• The Y-axes
• The aluminum grid platform
• The probe sensor

The Y-axes

If the Y-axes are not assembled properly, the 3D printing module will probably push into the print sheet in the first calibration point or the fifth calibration point. 

There are two grooves on the base plate and the Y-axes should fit into the grooves. You can refer to the following image.

The aluminum grid platform

There are some screws on the aluminum grid platform and those screws should face the downside. It will cause the problem if the screws are face upside. 

The picture below is an image of the correct installation.

The probe sensor

Please refer to the steps in the following link to have a check on the probe sensor. https://support.snapmaker.com/hc/en-us/articles/360046839854-How-to-adjust-the-probe-proximity-sensor-in-the-3D-printing-module- 

Please feel free to contact us at support@snapmaker.com if the tips above can not help you solve the problem.