Elephant foot

The base flares out, so parts no longer fit together and the footprint is oversized. It is the weight of the part pressing hot, soft plastic outwards while the bed keeps it above its softening point. Two real fixes and one compensation.

Looks like: The bottom one or two layers bulge outwards, so the base is wider than the rest.

Fixes, in the order worth trying

1 · Try this first

Raise the Z-offset slightly

The usual cause is a first layer squashed harder than it needs to be. There is a narrow band between "not sticking" and "elephant foot" — you want the least squish that still gives a solid, gap-free first layer.

Raise the Z-offset by 0.01–0.02 mm and re-print. If gaps appear between first-layer lines you have gone too far; back off by half a step.

2 · Try this first

Lower the bed temperature after the first layers

A bed that stays hot keeps the bottom of the part soft for the entire print, and the weight above keeps pressing it out. Dropping 5–10 °C after the first few layers lets the base set without hurting adhesion.

Build Plate Temperature (initial vs. rest): Cura → Material → Initial 60 °C, then 50–55 °C for PLA
Bed temperature → other layers: OrcaSlicer → Filament → Filament → 5–10 °C below the first-layer value

3 · Common cause

Apply first-layer horizontal compensation

Shrinks the bottom layers in the slicer to cancel the bulge. This is a compensation, not a cure — but for a part that must fit a hole, it is the fastest route to dimensional accuracy.

Initial Layer Horizontal Expansion: Cura → Shell → −0.1 to −0.2 mm
Elephant foot compensation: OrcaSlicer / PrusaSlicer → Process → Quality → Precision → 0.1–0.2 mm

4 · Less common

Chamfer the bottom edge in CAD

A 0.4–0.6 mm chamfer on the bottom edge gives the bulge somewhere to go, so the part still measures correctly at the mating surface. Standard practice for printed parts that must fit something.

Change one thing at a time. If you adjust temperature, retraction and speed together and the problem goes away, you have learned nothing and you will be back here next month. Re-print the same test object after each single change.

Frequently asked questions

Is elephant foot the same as over-extrusion?

No. Over-extrusion makes every layer too fat; elephant foot affects only the bottom one or two. If your walls are also bulging further up the part, you are looking at over-extrusion or a flow-rate problem instead.

Why do my parts not fit together even though the model is right?

Elephant foot is one of the top causes. The first layers being 0.2 mm wider than designed is enough to stop a peg entering a hole. Measure with calipers at the base and 5 mm up — if those numbers differ, this is your problem.

Does elephant foot compensation affect the rest of the print?

No — it only shrinks the first layers, by default just the bottom one or two depending on slicer. It has no effect on dimensions higher up, which is exactly why it works as a targeted fix.