The base of the part is flared (elephant foot)
Elephant foot is the opposite effect of a first layer that will not stick: here the nozzle squashes too much and the weight of the hot material flares out the base. It is a surface finish issue, but it ruins any part that needs to fit together with another.
What the failure looks like
The first few layers stick out by a few tenths of a millimetre compared to the rest of the part, leaving a lip. The part does not sit flat and mating parts become impossible to fit.
Causes, most likely first
- 01
Z-offset too low
The nozzle is squished against the bed.
- 02
Bed too hot
The plastic in the first few layers never fully solidifies and gives way.
- 03
Heavy part or small base
The weight from above compresses the soft base.
Step-by-step fix
1. Raise the Z-offset by 0,02-0,04 mm
Just enough so the first layer remains uniform without a side ridge.
2. Enable elephant foot compensation
In Cura it is called 'Initial Layer Horizontal Expansion', in PrusaSlicer and Orca 'Elephant foot compensation'. Start at 0,15-0,2 mm.
3. Lower the bed by 5 °C after the first layer
PLA at 60 °C on layer 1 and 50-55 °C from layer 2 onwards.
4. Add a 0,5 mm chamfer in the design
It is the ultimate solution for functional parts: the chamfer absorbs the flaring.
So it doesn't happen again
- Always design bases with a 0,4-0,6 mm chamfer at 45°.
- Do not use ABS bed temperatures with PLA just because it 'sticks better'.
Related questions
How much flaring is normal?
With everything well tuned, less than 0,1 mm. If you measure a 0,3-0,5 mm lip, you have too much Z-offset or excessive temperature.
Keep reading
What if it isn't worth your time?
Sometimes the part is more urgent than the learning curve. We're a workshop in Viladecavalls: send us the file and we'll print it with the right material and settings.
Still not working?
Tell Marco which printer and material you use and he'll tell you what to change.
Impresión 3D