A very similar problem to elephants foot, sans the flared-out first layer.
Signs of walls caving in:
Part of the wall of a print has caved in and then returned to the correct structure after a few layers.
Explanation:
The weight of the subsequent layers crushes the lower layers that never had a chance to fully harden.
How to fix:
Lower the bed temperature. Make sure you’re within the heated bed temperature range advertised by the manufacturer. The highest point in the range should never exceed 10°C below the glass transition temperature (rigid.ink Tg are available in the downloadable datasheets in the settings tab on product pages).
Set your printing temperature lower. The cooler you can print, the quicker the printed filament will cool, preventing layer crushing and caving.
You can also try increasing the cooling fan speed if not already at 100%. Do check with the manufacturer this is suitable for the material you’re using.
Filament specific tips:
PLA is often printed with 100% cooling fans anyway so if you’re seeing caving in, it suggests your printing temperature is too high. We always suggest starting at the lower end of the suggested temperature range and work your way up. High quality, pure PLA will be best printed at or below 200°C.
ASA does not like fans or draughts. Part cooling fans should not reach more than 10-20% with ASA. A warm ambient temperature is best but that doesn’t mean print at the hottest temperature within the range. Try reducing your printing temperature if you experience caving in with ASA.
For other filaments that you’re already printing at 100% part cooling fans, try adding extra external fans next to the printer to provide further cooling, if reducing the print temperature is not effective enough.