Accurate calibration/dimension test

cults3d

There is an updated version of this: https://www.thingiverse.com/thing:2484766 This test jig is designed to analyze the dimensional accuracy of a printer using engineering methods, but fear not: an Excel sheet is included that performs all the math. Simply print, measure and type in the numbers - a caliper will be needed. Note that calibration is normally not necessary for modern printers, and calibration cubes are very coarse; check out https://www.youtube.com/watch?v=Mbn1ckR86Z8 This method is more accurate than other calibration/testing methods because: - The edges have chamfers to eliminate the effects of the first and last layers. - Corners are rounded to minimize the effects caused by sudden direction changes. - Unlike a calibration cube, the Excel sheet analyzes the difference in the length of the columns instead of their total length. This reduces the influence of some effects that would distort the calibration, such as z-wobble or over-extrusion. - It uses the total length available for typical calipers (155mm), reducing the influence of random effects. - By analyzing five values per axis instead of one, the influence of random effects is reduced. A derived recommendation for design tolerances is included based on a typical engineering approach (3sigma). The Excel sheet is protected against unintended changes, but there is no password. Simply deactivate the protection to edit the formulas if needed. To get some statistical data: If you have performed this test, please post the standard deviation for X and Y in the comment section along with the printer and slicer used - thanks in advance. Update 1.5.2017: Small corrections were made to the STL file; a small version (145mm) was added for smaller heatbeds. Update 4.5.2017: The Z Axis was added, and now all distance differences are evaluated to get more data and a more accurate calculation. A histogram was also added.