In the field of 3D printing, FDM (Fused Deposition Molding) printers are widely used in education, manufacturing and personal enthusiasts because of their simple operation and low cost. However, in order to ensure the printing quality and the probability of printing success, it is an indispensable and important step to calibrate the printing platform (also called printing bed or hot bed) correctly.

1. Why do I need to calibrate the printing platform?

The level of the printing platform directly affects the effect of the first layer printing. If the nozzle is too close to the platform, the material may not be extruded smoothly or even scratch the platform; If the distance is too far, it will lead to poor adhesion of the printed layer, edge warping, separation and other phenomena. Therefore, good platform calibration can significantly improve the printing success rate and finished product quality.

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Second, the preparation work before calibration

1. Turn off the heating bed and nozzle for heating to ensure safety.

2. Move the print head to the zero position (usually the left front corner).

3. Prepare a piece of A4 paper or a special 0.1mm feeler gauge.

4. Ensure that the printing platform is clean and dust-free, and use alcohol to wipe the surface.

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Three, manual calibration steps (take the common platform with spring leveling screws as an example)

1. Start the printer and preheat the nozzle and hot bed: set the appropriate temperature according to the materials used (such as PLA and ABS).
　　2. Move the print head to the four corners of the platform and adjust the screws under each corner one by one:

-A4 paper should be inserted between the nozzle and the platform, which should have a slight sense of friction, but it can be pulled out smoothly.
　　-If the paper is jammed or too loose, you need to adjustment screw clockwise or counterclockwise until the gap is appropriate.

3. Check the center point of the platform: there are no adjusting screws in the center of some printer platforms, but it is necessary to ensure that the area is in a consistent gap with the four corners.

4. Repeatedly check all points to ensure that the platform is level in the whole range and the distance from the nozzle is consistent.

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Four, the use of automatic leveling function (such as BLTouch, capacitive sensor, etc.)

For FDM printers that support automatic leveling, the following operations are required after manual preliminary leveling:

1. Run the automatic leveling program (usually triggered in the printer menu or by G code such as G29).

2. The printer will automatically detect the height of the platform and generate a leveling grid.

3. Fine-tune according to system feedback, and repeat test printing (such as printing a test box or the first layer of test pattern) to confirm the leveling effect.

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V. Common Problems and Solutions

-The first layer of printing does not stick to the platform: it may be that the platform is overheated, the nozzle is too high or the platform is dirty, so the platform should be cleaned and leveled again.

-The nozzle is pressed against the platform: it means that the platform is too high, and the leveling screw in the corresponding area needs to be lowered.

-Corner tilt: the platform may be uneven locally, so it needs to be leveled again or auxiliary structures (such as edge fences) should be used.

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VI. Conclusion

Platform calibration of FDM printer is a basic but critical operation skill. Whether novice or veteran, leveling the platform regularly can effectively improve the printing quality and reduce the failure rate. With the development of technology, automatic leveling system is gradually popularized, but manual leveling is still the basis for understanding the printing principle and coping with emergencies. Mastering the correct calibration method will lay a solid foundation for your 3D printing.