Top 3D Printing FAQ: Solutions to the Most Common Print Failures and Quality Issues

Top 3D Printing FAQ: Solutions to the Most Common Print Failures and Quality Issues

Whether you are setting up your first printer or dialing in engineering filament on an industrial toolhead, unexpected print artifacts can be frustrating. Here are answers to the top questions asked by 3D printing technicians, complete with actionable diagnostic fixes.

Q1: Why are the corners of my print lifting and warping off the bed?

The Root Cause: Differential thermal shrinkage. As extruded plastic cools from 200+ deg C down to room temperature, it contracts. If bed adhesion or chamber ambient temperature is insufficient, contracting upper layers lever the corners upward.

• The Fix:
  • Increase bed temperature by 5 deg C (60 deg C for PLA, 80 deg C for PETG, 100 deg C for ABS/ASA).
  • Add a 5mm to 8mm Brim in your slicer to expand the perimeter footprint.
  • Eliminate drafts: Close enclosure doors and turn off high room air conditioning fans.

Q2: What causes Elephant Foot on the bottom layers?

The Root Cause: Over-squishing the first layer combined with excessive bed heat that keeps bottom layers soft while upper layer weight compresses them outward.

• The Fix:
  • Enable Initial Layer Horizontal Expansion (or Elephant Foot Compensation) in your slicer with a value of -0.15mm to -0.20mm.
  • Verify your Z-offset is not plowing into the bed.

Q3: Why did my print shift horizontally halfway through?

The Root Cause: Stepper motor step loss caused by nozzle collisions with curled infill, excessive travel acceleration, or loose drive pulleys.

• The Fix:
  • Switch away from Grid Infill: Grid infill crosses intersecting lines on the same layer, creating hard raised plastic bumps the nozzle slams into at high speed. Switch to Gyroid or Cross Hatch infill.
  • Enable Z-Hop on Travel (0.2mm to 0.4mm) so the nozzle lifts over printed perimeters.
  • Check that the grub screws on your motor drive pulleys are securely tightened on the motor D-shaft.

Q4: Why are my printed screw holes smaller than my CAD model?

The Root Cause: Circular toolpaths naturally pull inward under filament tension as molten plastic wraps curved arcs, shrinking internal hole diameters.

• The Fix:
  • In Bambu Studio / PrusaSlicer / Cura, adjust X-Y Hole Compensation to +0.1mm or +0.15mm.
  • Print outer perimeters first (Outer/Inner wall ordering) for superior circular accuracy on press-fit bearings and screw threads.