Hướng Dẫn cân bằng giường máy in FFF/FDM 3D

Có rất nhiều thông số cần xem xét khi xử lý máy in 3D và chúng ta thường gặp phải những trở ngại do các yếu tố không chắc chắn làm giảm chất lượng hoặc sự thành công của mỗi bản in.

Trong bài viết này, chúng mình sẽ mô tả kỹ thuật giải quyết vấn đề phổ biến nhất nhưng quan trọng nhất trong in 3D – san phẳng giường, đồng thời giải thích tầm quan trọng và thời điểm bạn nên san bằng giường của mình

Tại sao san phẳng giường lại quan trọng?

Fused deposition modeling (FDM) 3D printer is a method of additive manufacturing where layers of materials are fused together in a pattern to create an object. More importantly, the object is printed on a flatbed where it allows the material to extrude evenly across the entire build surface. Without an evenly flat or leveled surface, achieving a perfect print will be almost impossible.

When do I need to level my 3D printer bed?

Straight to the big question, when do I need to level my bed? Here are a couple of problems that are normally caused by an uneven bed:

1. Under extrusion – Filament seems stuck and no filament is leaving the nozzle in certain areas.
2. Under extrusion – Clicking sound at the extruder due to blockage at the nozzle.
3. Poor bed adhesion – Filament fail to stick on the bed surface
4. Poor bed adhesion – Filament shape and sizes vary across the bed surface
5. Physical damage – Nozzle is scratching your bed surface
6. Physical damage – Ugly first layer or first layer is pulled off by the nozzle

Knowing when to level your bed is as equally important as the technique itself. In some cases, poor bed leveling can cause the accumulation of filament in the nozzle which will lead to more troublesome issues, ie: clogged hotend. Hence, it is always recommended to stay alert during the first few layers of a print to ensure the bed is leveled correctly.

Best practices #1: Level your bed after every 5 to 10 prints. Level your bed if the printer is being moved.

How to level my 3D Printer bed?

Bed leveling may sound simple, look simple, but in reality, it is really tedious to get it right. Here are 6 preparation steps to take before you start leveling your printer:

1. Heat up and clean your nozzle from residue. Recommended using a nozzle copper wire brush.
2. Clean the bed surface from debris with isopropyl alcohol (IPA) on a paper towel.
3. Set your printer to the home position.
4. Create some distance between the nozzle and the bed by adjusting the four screw knobs under each corner of the bed.
5. Heat up your print bed to 60°C and nozzle to 150°C (Recommended Temp.)
6. Prepare an ordinary sheet of paper (Recommended 80-100 gsm)

Once your printer is ready for leveling, go ahead and start leveling with these 5 easy steps:

1. Slide the paper underneath your nozzle
2. Rotate the corner screw knob while sliding the paper between the nozzle and the bed.
3. Close in the distance between the nozzle and the bed until you feel the paper has a small amount of resistance against the nozzle.
4. Repeat step 1 to step 3 on all corners.
5. Run a simple bed leveling test print (Thingiverse: 4711071).

To ensure better results, repeat step 4 again to double confirm the bed is leveled.

Leveling your bed is basically achieving same distance between nozzle and bed at all sides of the print area.

With a few more practices, you will eventually get better at bed leveling within a short amount of time while maintaining leveling precision.

Can I level less often?

Yes you can! We understand that as you progress through your 3D printing journey, it gets tiring after repeatedly leveling your bed. Here are a couple of things you can try to reduce the need to level your bed:

1. Make sure everything is tight on the printer. We recommend to constantly check on the bolts beneath the bed and the gantry to ensure it is not loosen. A wobbly bed or hotend is also the result of an untight bolt.
2. Upgrading to stronger bed springs is one of the best inexpensive upgrades for a 3D printer. It allows sturdier bed while reducing after affects from shocks and bumps during movement of the printer.
3. Turning your printer into an autoleveling machine! The most popular bed leveling sensor adopted for 3D printer such as Ender 3 is the BLTouch.

Best Practices #2: Always monitor the first layer to make sure the bed is tuned in correctly.

Ultimately, the most convenient way is to get an auto-leveling 3D printer such as the Creality CR6-SE. Such machine comes with built-in leveling sensor and program which allows it to determine the distance between the bed and nozzle by moving to each corner of the bed.

Note worthy bed leveling tips

Reduce the gap between nozzle and bed if:

1. Filament is unable to stick on the bed.
2. Object adhesion is not strong and comes off easily during mid-print.

Increase the gap between nozzle and bed if:

1. No filament extruding out from the nozzle, causing extruder to click.
2. Filament accumulates on the nozzle resulting in blobs.
3. Thin and barely visible first layer.
4. Nozzle scratching on the bed surface.

All in all, it takes practice to master the technique. Hopefully you are now equipped with the proper skillset to get started and remember to always monitor the first layer to ensure the bed is leveled correctly!

Good luck and happy printing!