Why is calibration important?
Calibrating the extruder is crucial for FDM 3D printing for a number of reasons. Its purpose is to ensure that the 3D printer feeds the exact amount of filament through the hot end during printing.
If too little filament is used, either gaps will form between the layers, or the layers themselves will be unstable or missing. The adhesion will also not be reliable, which will lead to delamination and warping.
On the other hand, if there is too much material, the finished models will have issues with excessive extrusion, which will also disrupt their structure. This could even cause clogging of the filaments in the hot end.
The following steps for calibrating the extruder will help you avoid such problems!
But before that, here are the materials and tools you will need:
- 3D printer
- Computer with installed cutting software
- Inelastic FDM filament
- Shoemaker
- Permanent marker
How can you calibrate the extruder in 6 easy steps?
1. Place the thread in the printer.
The first thing you need to do is preheat the printer nozzle to the required temperature, depending on what filament you are using.
In case you have already loaded the filament, preheat to the temperature suitable for it. If you haven't yet, but the printer is already heated, load the thread as usual, making sure to remove any previously used materials.
2. Connect to the computer.
Connect your printer to the computer via USB or Wi-Fi. Then install software to send single-line G-code commands to the printer. You can use Simplify3D, Pronterface, OctoPrint and others.
When you are done with this step, find the slicer setting for connected printing.
If you are using Simplify3D, this setting is in the control panel. For most RAMPS and Atmega printers, you can also use the Serial Monitor panel in Arduino IDE.
Finally, activate Relative Mode on the extruder by sending the command M83 to the printer.
3. Mark the filament and start extruding.
To calibrate the extruder, you need to send a 100mm filament through the hot end. However, before that, use the caliper and marker to mark the filament 120mm before the entrance of the extruder.
Then send the command G1 E100 F100 to the printer. This is done for one minute to avoid issues with filament tension or pressure in the hot end.
4. Measure again.
"After it finishes, the 3D printer should have extruded exactly 100 mm of filament. To ensure this, measure the distance from the extruder to the mark you made on the filament."
"If the measurement is 20mm, then the extruder is properly calibrated. But if the measurement is more than 20mm, it is likely a case of insufficient extrusion."
On the other hand, if you measure less than 20mm, your printer is over-extruding.
5. Calculate the correct ratio between steps and millimeters.
"To properly set up the extruder, you first need to determine the current discrepancy to see where the error is."
Start by sending the command M503 to the printer. It will return a string of values that will be displayed on the monitor. From them, find the line that starts with “echo: M92” and the E-value, which is usually at the end of that line. This value represents the current ratio of steps to millimeters.
Regarding the value of the physical ratio, first, you need to know how much filament has actually been extruded. This can be easily calculated by measuring the distance from the extruder to the thread marking, and then subtracting that value from 120.
| 120 – [length from the extruder to the marking] = [actual extruded length] |
"Then you need to determine how many steps the extruder has taken to extrude that amount of filament. This value can be determined by multiplying the steps/mm value by the length that needed to be extruded - in this case, 100mm."
| [steps/mm value] x 100 = [steps taken] |
By calculating this, you obtain the actual physical value of steps/mm by dividing by the extruded length.
| [steps taken] / [actual extruded length] = [exact steps/millimeters ratio] |
'Once you calculate the exact ratio, the only thing you need to do is enter this value in the 3D printer settings.'
6. Set a new value.
To set a new value for steps/mm, first send the command M92 E###.#, replacing the hashtag symbols (#) with the exact value of steps/mm that you obtained from the last step. Save this in the printer's memory by sending the command M500.
At this moment, it is good to turn your printer off and on again. After that, send the command M503 again and make sure that the E-value corresponds to the newly set value.
If such correspondence is missing, repeat the first part of this step.
To check if your extruder is already properly calibrated, you can repeat steps 1 to 4. This time you should get a value of exactly 20mm between the extruder and the mark. If not, recalculate the value and save it again.
"After completing these 6 steps, your printer should have a perfectly calibrated extruder!"
