FFF Printer Tuning for Accuracy

By accounting for a variety of factors that affect the accuracy of our printing process, we can dial in our 3D printers to get a fairly sufficient level of accuracy for functional, mechanical prototypes. Here's a breakdown of the factors to tune.

Extrusion Width

Even though nozzles come in fixed sizes, the resulting extruded line is almost always slightly thicker after it has been deposited onto the forming part. This happens for a variety of reasons. But the main reason is that each subsequent layer is squished onto the prior layer with some overlap to ensure that the two layers fuse. Accounting for this thickness is key to getting accurate feature sizes, especially for small holes.

Measuring Extrusion Width

We can measure extrusion width from a flat surface of a single-layer thick wall. To create such a test object, simply print a cube with an open top in vase mode. From here, measure the wall with a pair of calipers.

measuring extrusion width from an object printed in vase mode

Accounting for Extrusion Width

Most slicers actually have a setting for extrusion width. Simply input your measured value.