Calibrate your 3D printer: What you need to check

Whether it’s before you first print or after hundreds of prints, as a high-precision machine with so many moving parts, your 3D printer always needs calibration to make sure your printing outcome is perfect. Here we will provide you a list of 3D printer tests that you can check with.

Tools required for calibration

Before starting, here is a list of tools you will need when calibrating. You can prepare it in advance.

• HEX Drivers
• Spanner (open end wrench)
• 120mm or longer ruler
• Digital Caliper
• Post-it Note or sheet of standard 20lb laser paper
• Super Lube or Equivalent Silicone Grease

A free browser-based tool (link: https://3d-printing-tools.drvax.com/ )

We will list all the things you need to check below. For some of these items, you can adjust them with drivers or spanners. However, you need to adjust the other items with the help of Marlin firmware sending Gcode to your printer. This browser-based tool (link: https://3d-printing-tools.drvax.com/ ) can help you calibration your 3D printer by sending Gcode to your connected printer.

To start this, let’s connect your 3D printer to the website and have fast browsed the website.

The entries on the left of the website lead you to the different features of the website. You can review the checklist of tools and maintenance steps at “CHECKLIST”.

“TERMINAL” is where you connect your printer and send commands to your printer. You can find the list of common Gcode commands on the right of this page.

The other two entries are used in specific calibration steps and will be mentioned below.

In order to connect your printer, you need to turn on your printer and connect it to your computer using a USB cable. Then, click the “CONNECT” button on the “TERMINAL” page, find your printer in the list, choose it can connect it.

What You Need to Check Before Your First Print

Maybe your device came as fully assembled or calibrated, with all the moving parts that likely misalign, you need to check it again to minimize the vibrations from the 3D printer.

• Print a Calibration Cube to Verify Print Quality

A calibration cat is a great model to test if your 3D printer is perfectly adjusted. You can check overhangs, layer alignment, and other features by printing a calibration cat. Don’t forget to check the dimensions of the calibration cat to check the accuracy of your 3D printer using a Caliper. If the calibration is within a tenth of a millimeter, the accuracy of your printer is spot on.

• Tighten all the bolts just right

The first thing you need to check is the bolts. There is a various connection and bolts on your X-axis, Y-axis, extrusion and any other parts of your 3D printer that you need to tighten them using HEX drivers. Or your printer will wobble a lot when printing. Just make sure don’t overtighten which may cause the plastic part to break. To get just-tight, you need to tighten bolts figure tight and then turn 1/4 round more.

• Adjusting eccentric nuts

You can find a few wheels ride on the extrusions, underneath the print bed, on the side of the X-axis, and other places that are adjusted by adjusting eccentric nuts using spanners. You have to make sure all these nuts are snug and there is no extra movement.

• Make sure the Belts are firm

Belts are the main movers of the major parts of the 3D printer so that the printing elements are able to run smoothly. With loose belts on your 3D printer, you will find rippling along the edges of your object. Tighten the belts referring to the instruction manual of your device and make sure not over tight. You should be able to push belts down slightly but they should feel firm.

• Level the Print Bed

The importance of leveling the print bed goes without saying. You can find hundreds of videos on the Internet that teach you how to manually level the print bed. Just follow the guide and level your print bed using a post-it note or a standard 20lb laser paper. We recommend you manually level the print bed periodically even your printer has the ABL system. Because the detector on your 3D printer may have errors occur.

• Calibrate the Extruder

Calibrating the extruder is actually meaning calibrate the stepper motor. 3D printers use step motors to move the axes and the extruder by rotating small steps. And we need to know how many turns are required in order to feed a millimeter of filament into the extrusion.

We will use the online tool to send a G-code that command the 3D printer to feed 100-millimeter filament and measure how much the extrusion actually fed. Then, use the percentage of what extruded and what we expected to adjust the steps in our firmware.

1.After connection, you can retrieve all the saved parameters of your 3D printer by sending the Gcode M503. We can find “steps per unit” at lines 64 and 65. The parameter is shown at the end of line 65, as the E93 in the example picture, refers to the number of steps that the extruder motor takes per millimeter of extruded filament.2.Measure 120 millimeters of filament from the top of the extruder and mark the point on the filament. By measuring filaments more than 100 millimeters, the mark won’t disappear in the extrusion when extruding too much.

3.Set the temperature to 200℃ by sending the command “M104 S200”.

Enter the command “G1 E100 F100” to push 100mm of filament through the extruder at 100mm per minute.

4.Measure the length of the filament from the top of the extruder to the mark point after the extrusion is finished. Call this value A, and 120 – A = Actual extrusion.

5.If 120 – A = 100mm, the extruder is calibrated correctly. If not, we need to update the parameter of “E93”. Go to the menu entry called “EXTRUDER STEPS” and enter the value according to the instruction, new calculated E value will display below.

6.At last, enter the “G92” command to reset the E value. If you want to save the new value, use the “M500” command.

• Run a PID Calibration

When it comes to temperature control, it can’t be as simple as turning on the heating element, waiting for the bed or the nozzle to reach the given temperature, and then turning off the heating element. The residual heat in the heating element will cause an overshoot. Instead, 3D printers use the PID algorithm to increase temperature accuracy.

1.Use the “M503” command and find the saved PID value at lines 46 and 47.

2.Enter “M303 E0 S220” to start the PID extruder autotune. The current temperature will be reporting back.  

3.You will get the new PID value after the PID autotune is finished.

4.Update the new value using M301 command. Likewise, if you want to save the parameter permanently, enter the M500 command.

• Print another calibration Cat to Verify Print Quality

After all the calibration is done, you need to print another calibration cat to make sure your 3D printer is properly aligned.

Every 5 print

• Clean the Print Bed Thoroughly

The cleaning of the print bed surface can affect a lot on the bed adhesion. Clean the print bed thoroughly to improve the performance of the first layers.

Every 20 print

• Check Bolts and guide wheels are snug
• Check Belts are firm

As your 3D printer operating and the parts moving, all these connection may get loose. Check all the bolts and nuts again, make sure the main structure of your 3D printer is firm.

Every 50 print

• All "Every 20 Print" checks, plus ...
• Relevel the Print Bed Verify and Calibrate the Extruder
• Print a Calibration Cube
• Run a PID Calibration
• Lubricate Z-Axis Screw

Make sure the Z-axis rob is slightly lubricated. Just rub some Super Lube or Silicone Grease up and down on the Z-axis robs using your finger, and you can do it more often as the increase of print times.

A fine-tuned 3D printer can improve the printing result significantly. Periodically recalibrate your 3D printer can maintain the stability of your device. Frequently test your 3D printer following the list above and check the quality of your prints, make sure your 3D printer is always ready for performing well.