So, you are excited about using your new 3D printer, but you realize you cannot jump straight in. You’ll need insight into why calibration is done and the basics of the process. This guide will shed light on calibration details in a way that breaks down the science for easier understanding.
Why You Should Calibrate a 3D Printer
Mechanical equipment with moving parts need some level of calibration to work efficiently. 3D printers are incredibly accurate products but only if the right amount of calibration is done in the initial setup and every time they are moved. Calibration is a process of fine tuning and adjustments used to correlate the measurements of an instrument against a standard to check the equipment’s accuracy. Calibration ensures that each print is delivered the same so that your creations are identical.
3D Printer Extruder Calibration
The extruder is the component that spits out the hot filament. There are two problems to avoid with the extruder. It can either utilize too little or too much filament. Low filament levels will affect adhesion, and some parts will have spaces between layers. Prints will have their layers warping or delaminating. In the case of too much filament, prints will be delivered in droopy details.To start, you will need your printer, permanent marker, a computer installed with slicer software, calipers, and a flexible-filament.
- Load the filament – The nozzle of your printer should first be preheated to the required temperature for the particular filament you will be using. Load the filament like you normally do and remove any previously-utilized material.
- Connect your PC – Link your 3D printer to your computer via USB or WiFi. Open a slicer software that lets you deploy single-line g-code commands to your printer. Such software includes OctoPrint, Simplify 3D, and Repetier Host. You will need to navigate to the tethered printing section of the software. Activate Relative Mode on your extruder by sending the M83 command to the printer.
- Mark the filament and begin extruding – Tocalibrate the printer’s extruder, we will eject 100 mm of filament via the hot end. Use the marker and calipers to identify the filament 120 mm mark before the extruder’s entrance. The next step involves sending the G1 E100 F100 command to the printer. The equipment will run 100 mm filament via the extruder. This process should run within a minute to prevent any problems with pressure or filament tension which can compromise the results.
- Measure again – To check the amount of filament extruded, measure from your extruder to the initial mark on the filament. Your extruder will be properly calibrated if the measurement is 20 mm. If it less than 20 mm, the printer is over-extruding and it is under-extruding if it is more than 20 mm.
- Measure the right steps per millimeter value – Send the M503 command to your printer. A series of values will be shown on your monitor, and you should look for the one that begins with echo-M92. The E-value will be at the end of the line. This value is the current steps/mm. Use the amount of the extruded filament and the marked value to determine the correct steps/mm value.
- Set a steps/mm value – Send the M92 E###.# command where the hashes replace the actual steps/mm value you recorded in the last step. Use the command 500 to save this value to the printer’s memory. You can switch the printer off and back on and send the 503 command. Ensure that the E value reflects your calculations. You can redo steps 1 to 4 to ascertain if you will obtain 20 mm between the mark and the extruder. Your extruder will be calibrated if that is the case.
How to Calibrate the X, Y, and Z Axes
After calibrating your printer’s extruder, it is essential that you also calibrate the axes. The process is similar although there is a need to print something in the case of axes. You can opt to print a small cube, for example, by either designing one yourself with software or downloading a free model.
Measure every direction after the cube has been printed. The computation is the same as that done on the extruder. You will need to calculate the level of filament extruded. If the cube should be 20 mm on every side, for example, and we measure 20.30 in the Y direction, this measurement will be used in the calculation. If the M92 value for X, on the other hand, was supposed to be 100.00, we would update the readings by sending the printer the command M92Y98.52 since 20×100/20.30= 98.52.
As done with the extruder, it is more accurate to record multiple measurements and calculate the average. You do not need to print many objects, however, as you can measure the cube at various positions.
How to Calibrate a 3D Printer Bed
The first step is ensuring that the hot-end nozzle is at a set distance from your print surface and that the surface is flat and level.
The procedure commonly involves the slackening or tightening of about four points on the build bed. This surface is typically comprised of PCB materials and fixed by spring bolts. An additional process is to also level other primary parts of the printer like the vertical Z movement and ensure they are at equal distance on each side.
The Z-axis end-stop is the major sensor that positions the hot-end rightly far from the build bed. The sensor can either be magnetic such that it is tuned to a particular distance by twisting a small rotary knob called a potentiometer or it can just be a mechanical switch turned up and down. A small LED light commonly lights up when the axis is deployed to the home position. If it fails, your equipment has an incorrect orientation which you will need to change to false in the settings.
Evaluate the performance of the end-stop switches by sending commands to every axis to move into the home position in turns. Set the distance of the Z-axis in such a way that the hot-end nozzle sits far from the bed. The best procedure to follow is to move the print head to the bed’s center. The 3D printer will assist you via the user interface or the LED screen. The sensor evaluates the leveling and suggests adjustments if need be. You can go ahead in printing if everything is level as the first layer will finish smoothly and evenly.
The distance you need to set depends on how appropriately you leveled the build bed and on the nozzle size. A flat sheet of glass is often a good selection for the build surface. At the start of the process, ensure that you can slide one sheet of office paper below the nozzle while it sits in the Z home position. Check this gap at the center and in the four corners for uniformity.
What is a 3D Calibration Cube?
Calibration cubes are geometric shapes designed to help achieve accurate prints. The shapes are quite simple, and they offer maximum precision. They are ideal for lower-end equipment that have not been industry-tuned and for assembly-needed kits. You can adjust a printer’s settings with the cubes to produce precise parts. The actions you can perform with these cubes include:
- Adjust your material settings – If you are well versed with the configurations of the motion system of your printer, you can utilize the steps/mm calculator of Prusa Research to determine the actual steps/mm settings you require. The source of error will therefore only lie with the print material. If you get undersized prints frequently, the problem is material shrinkage, and you can change the “shrinkage percent” setting on your slicing software. The deviation you witness divided by the dimension you want is a good value to begin with.
- Tune the steps/mm setting -These settings guide the printer on how much to rotate every motor to finalize a millimeter of travel. If you are not well-informed on your printer’s motion system, the cubes will assist you to lock down on these values.
- Fix printer ringing – The sharp corners of the cubes can easily show ringing artifacts which can cause poor surface finishes.
- Test for Precision – Calibration cubes come in handy when you want to determine the accuracy of your printer. You can use them to implement tighter clearances for the printer’s parts.
Calibration cubes are produced in several varieties. The classic one is 20 mm, and its faces are commonly labeled X, each Y, and Z. It is appreciated for its simplicity which makes it easy to use. Each dimension should accurately measure 20 mm for precision. An upgraded version of the classic cube features four layers at 10 mm, 15 mm, 20 mm, and 25 mm. A notch is placed at the front to display orientation. This cube is particularly important for identifying material shrinkage. The calibration cat is made of cuter where the head and tail are of different sizes to determine material shrinkage.
Buying or building a 3D printer is the first step to quality printing. If the machine is not properly calibrated, you will get inconsistent results or prints that are not any good. Calibration ensures that each print is identical regardless of the instruments used to produce it. This process involves the calibration of the extruder, axes, and build bed. If you are not too informed on the motion systems of 3D printers, you can make use of calibration cubes to simplify the procedure.