Model and printed-part dimensions: what are you comparing?

The dimension shown in a slicer describes the digital geometry in its current orientation. It does not guarantee a printed part’s final dimension or a correct assembly fit. Identify exactly what you are comparing before correcting size.

Bounding box or functional dimension?

A bounding box gives the model’s extent along X, Y and Z. A functional dimension describes a useful feature: a bore diameter, hole spacing or tab width. Overall width does not replace a hole’s internal dimension.

PrusaSlicer can move, rotate and scale a model. Uniform scaling preserves proportions; changing an axis independently changes them. Keep the orientation and initial state when comparing two displayed dimensions.

A local defect does not always call for global scaling

PrusaSlicer describes elephant foot as widening of the first layer compressed against the bed. Its compensation targets that layer. Scaling affects the whole geometry: these are different operations.

Material shrinkage can also affect dimensions; Prusa notes this for ABS in particular. No generic percentage is adopted here. The first-layer guide helps examine the start before making a global correction.

Prepare a reproducible comparison

1. Select dimensions that actually determine the function.
2. Record the digital dimensions and model orientation.
3. Preserve the material, profile and project version.
4. If you print a trial, specify its state and measurement method.
5. Repeat relevant measurements rather than concluding from one point.
6. Decide whether the deviation appears global, local or still undetermined.

This procedure organises your validation. LayerBench3D has not used a sample or measurement instrument for this article.

Hypothetical example: correcting one dimension can move another

Suppose, only to illustrate the reasoning, a designed length of 100 mm and a recorded length of 99.4 mm. The deviation would be −0.6 mm, or −0.6% of the designed dimension. The inverse factor 100 / 99.4 ≈ 1.006036 would represent 100.6036% of the original scale.

This does not prove a global correction is appropriate: it would enlarge holes and other dimensions too. If the defect is localised at the base, the transformation could worsen an already correct area. Identify the cause and validate the affected dimensions before retaining compensation.

For the purely geometric calculation, use the resizing guide and its tool. For a fit, distinguish the numerical transformation, manufacturing assumptions and measurements actually performed.