As a DIY 3D printer, the TEVO Tarantula might night additional tweaks before its printing quality is acceptable. When the axes are not calibrated correctly, the measurements of prints will be off. By testing and calibrating the axes and extruder, prints can become one step closer to being perfect.
Uncalibrated axes will lead to longer or shorted measurements on measurable 3D prints. By printing an object with known dimensions, e.g. the XYZ 20mm Calibration Cube by iDig3Dprinting, the exact measurements can be compared with what it is supposed to be. The movement of the axes itself can also be measured and compared with the distance it was set to travel.
If any of the X, Y, Z-axis, or the extruder movement are off (calibratable up to a 100th of a millimeter), it will be beneficial recalibrate the incorrect measurements. By using the current steps (Steps/mm) set by the firmware for each individual axis, the following calculation can be used to determine its new steps:
100mm is a good measurement to use to move the axes. Note that the default current steps might be different for each axis. Before the X, Y and Z-axes are calibrated, the respective axis should be homed back to zero.
As an example: Assuming the X-axis only moved by 98mm (and it was supposed to move by 100mm) and the current steps are 80mm, the new steps will be 80mm x 100mm / 90mm = 88.88 (or 88.88/mm). The measured distance might be longer or shorter than 100mm.
After changing the steps, the settings should be stored (Control -> Store settings) and the new measurements should be taken again.