Ghosting: why ripples appear behind edges

Why the ripples appear

When direction changes suddenly, the frame and belts start to vibrate, see resonance. The nozzle then oscillates after the corner and repeats the shape of the corner in a smaller form. In image processing this is known as ringing.

That is why the ripples appear mainly behind sharp edges, letters and small holes, and fade with distance from the corner.

Faster printing makes the ripples stand out, slower printing reduces them. That is why high-quality printing of smooth surfaces takes longer, and it only pays off where appearance matters.

What helps

• Lower acceleration and speed, see print speed.
• Damping the vibration in the control, see input shaping.
• A solid stand, well-tensioned belts and a firm surface under the printer.
• A lighter print head, which vibrates less when direction changes.

CoreXY printers, like the ones we use, are built for fast changes of direction, see CoreXY, but they do not rule out ripples entirely.

What to do in the model

• Round sharp corners, as a fillet reduces the jolts at direction changes.
• Make text and fine engraved marks raised and larger instead, see relief.
• Avoid large flat walls with a small pattern, where ripples are most visible.

For your order

Ghosting is a cosmetic flaw and does not change strength. The surface in ordinary printing is layered, and fine ripples are part of it. If you have a part where looks matter, say in a note what is important to you. We photograph the batch before dispatch.