Why Do You Need To Calibrate Your 3D Printer?
When you are working with a 3D printer, it’s like caring for a baby. You need to look after it and keep it well maintained. An essential part of this is regularly checking the extruder calibration. We no longer use meters or centimetre, because the most common unit now is millimetres and microns. Things can’t get more precise than this!
What Is And How To Use Calipers?
Callipers are devices that are used to precisely measure length, it’s like a ruler, but it is more advanced. I want to suggest that you should buy a digital calliper. These can be a bit expensive, but you will find that digital callipers are much easier to use. You will need to get calipers with at least 0.01mm precision or 0.0005. You can typically buy these from a DIY store.
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Before Making Changes, Make a BACKUP!
It’s always good to make a backup before any configuration changes. It doesn’t matter if you’re doing work on a computer, mobile phone or a 3D printer. Anything wrong can happen at any time, and this will result in you losing all the progress that you have worked on. So make sure that you do regular backups.
Okay, so to perform a backup of configurations for a 3D printer you will need Repetier Host this will be the software you will need to get before you can do anything else. You will need to connect your 3D printer using the USB cable provided, place this into a USB slot in your computer, and then press Control + P to open the configuration panel.
You can change the port, but I tend to leave it on auto, the baud rates are usually (115200 – 250000) then press “OK“. On the main screen, you will see connect (click this) then go into Config > Firmware EEPROM Configuration.
Now that you are on the EEPROM setting menu, click on export EEPROM data, I suggest you may want to take a print screen of the parameters in case you need to access a single value. After you have backed up your firmware, you can now start the extruder calibration.
Calibrating The Extrusion Step/mm
You need to start by measuring your existing extruder calibration. This requires you to preheat the nozzle to liberate the extruder. Set the temperature to at least 170ºC. This is typically the failsafe temperature. After you have preheated the nozzle, you will then need to disassemble the extruder. This will be a lot easier if you have a Bowden system, but if you don’t, it’s okay. If your 3D printer has a direct drive extruder system, you will need to remove the hot end block with dissipator this will help the filament to more freely.
Preparing The Calibration
Another good idea is to check the extruder’s tensioner. I lose it won’t pull the plastic correctly!
Start to remove the Bowden tube from the snap-fit locker. You can do this by pressing the plastic parts down, and then pull the PTFE Bowden tube up and out. Once you have finished removing the PFTE tube, you will then need to cut any excess filament away. Try to get it as close as possible to the end of the PTFE Bowden tube.
Measuring The Current Extruder Calibration
Once you have done the previews step, you will need to go back into Repetier host and “click on” extrude to 100mm. Only press this once! You will now have sent the extrusion commands, wait until the filament has stopped flowing out of the PFTE tube. Now, place the callipers with the left “ear” touching the PFTE tube and the right “ear” place it where the plastic ends. Using the digital callipers, it will display the value right away make sure you right this done. Make sure that the callipers have been ZEROED out before measuring. This is your initial extruder calibration.
You will need to go back in the EEPROM firmware setting, to do this a quicker way you can press ALT + E and then find where the E-Steps value is and write this down too, Do not close the firmware down as you will still need this up on the screen.
Calculating your Extruder Calibration
You will need to calculate the steps. This can be a simple equation. For example
The formula is: New _steps = old_steps (expected length / real length)
One this case: New_steps = 157.16 ( 100 / 99,45 >>> New _steps = 158,0291
Write the new value down on the firmware screen and press “ok.”
Finishing The Extruder Calibration
After saving the final value on your 3D printer, you should measure the results again. This is because there may be a small error. Follow the previews instructions until you get exactly 100.00mm. After fine-tuning the extruder step/mm, you will then need to reassemble the PTFE Bowden tube or the hotend, for direct feed extruders.
Now you will have an extruder that is calibrated! You should not have any problems with over extrusion or under extrusion again. Remember to set the “extrusion multiplier” or “flow” to 100% on the slicer of your choice. Otherwise, it will override your extruder calibration!
Calibrating the X, Y and Z Step/mm
To begin, you will need a calibration test model, there are hundreds on Thingverse, but the one that most people will use is called Benchy. This model is designed to measure from specific points to ensure accurate printing, including dimensional accuracy, warping, deviations and tolerances.
After the print has finished, open the firmware configuration you will find the X, Y and Z steps/mm, put then into a calculator and measure the print with the callipers. The correct value should appear on the calculator, replace this into the firmware, remember to save everything and make a back up of the new value.
To be sure that everything is in working order, print this part again, the measurements should be within 0.05 of the expected value.
Remember that if your X and Y values are very different, your circles won’t be round.
This guide is not intended to fix bed levelling issues or bad quality filaments those are requirements for this calibration to work.
Are your prints still not looking great? Check out our guide for tuning your extrusion width!