Thanks for starting this thread. Chen (@parachvte), it is not about the leveling as for the 3D module, because the problem can be on the material as well. If the material is flat (I’m carving on 16mm MDF), the leveling is not about removing hills and valleys out of the material. For me, it is about getting the bed/base level (spirit level) over the X as well as Y-axes.
I’ve noticed that due to the single mounting on the Y modules, my bed is lower on the back as on the front. With the downward force of the CNC, the bed is pushed downwards. The linear modules might be strong with the downward force on the connection point of the platform onto the Y axes. However, when the downforce is at the end of the bed, there is a rotational linear moment on the connection points.
In order to prevent these moments on the Y-axes, I’m planning to add additional support for the bed. I know there is someone that used an extension to the Y-axes to allow for 2 connection points per module but I’m looking into merely putting a rail below the platform with support vertically below the module (directly below the X-axes). Thus, the rail attached to the platform and the rail block (or linear bearing mounting) fixed to the base plate. I see there are holes in my A350 base plate at the correct positions. This will support the bed when the Y-axes are at the minimum and maximum points. Thus, the supports will counter the linear moment. The only problem with this will be that the bed can be pinched between the support rail and the CNC module (cutting bit). The second issue comes into the exact height for the support rail. Making small changes will need to be a manual change, similar to a manual bed leveling of other printers with a skrew setting.
I will copy both @Mika and @parachvte on my progress on this. Chen, I know you are on the software development side, I will copy @Edwin on this.