5 Ways How to Fix Scars or Scratches on the Top Surface of 3D Prints


As I’ve been 3D printing, in some of my prints, I’m noticing scars or some type of scratches on the top surface. It makes the prints look quite ugly, so I’ve been looking for the best ways to fix scars on the top surface of 3D prints.

You should fix any over-extrusion issues that you might be having to fix scars and scratches on the top surface of your 3D prints. Implement Z-hop into your slicer to strategically lower the print bed while 3D printing. You can also enable ‘Ironing’ which goes over the top surface and extrudes plastic to smooth it over. 

Keep reading this article to find out the details behind why this happens in the first place, then how to fix these scars once and for all.

Why Do You Get Scars or Scratches at the Top of 3D Prints?

3D printing comes with many benefits, such as you get to print every layer and surface separately, which you can then combine together.

This individual printing of layers gives you the chance to know when the surface of your print has started to get rough is having scars.

This could be the result of many reasons which I will be discussing with you. Along with the reasons, I will be explaining the solutions to fix them.

  • Overextrusion and extruding too much plastic
  • Nozzle hitting the surface
  • Bad slicer settings such as top layer speed
  • Problems with slicer software

How to Fix Scars or Scratches at the Top of 3D Prints

The scarring problem, as briefed earlier, can make your print model look ugly, actually. I will be listing and explaining all the possible solutions which can help you get rid of it.

You need to follow these solutions as it is, and if luck is by your side, you won’t have to face the scarring problem again.

Over-extrusion is a common cause of scars or scratches at the top of your 3D prints, so some solutions below are in relation to fixing over-extrusion, which should translate to fixing the initial problem.

It consists of lowering the temperature, adjusting your flow rate or extrusion multiplier, and adjusting the nozzle size.

This over extrusion problem makes more plastic to settle on the surface than it should have, and this causes it to be slightly thicker than intended.

Excess plastic on the surface of the print model makes the nozzle drag over it, which results in scarring or scratching.

1. Lower the Temperature

To decrease the presence of over-extrusion, you want to reduce the liquidity or reduce the viscosity of the melted filament.

  • Decreasing the printing temperature so it has more structure rather than freely flowing

2. Adjust the Flow Rate

A high flow rate is another factor which can cause over-extrusion, making filament come out too quickly out of the nozzle. You want to have a good amount of control over the melted filament so it can be extruded precisely.

Without a good flow rate, you can be left with those scars or scratches on the top of your 3D prints.

Adjust your flow rate to decrease the presence of over-extrusion if it is occurring.

3. Implement Z-Hop Slicer Setting

This is somewhat similar to the above problems, but it could also happen after you have printed a few layers.

The nozzle will not only scratch the surface, but it will also make a scratching sound, which will be a sign that the nozzle is hitting the print surface while moving from one location to another.

What you can do about this problem is as follows:

  • You can check the Z-hop in this regard.
  • Fix it by checking the height or the distance of the nozzle from the printing surface.
  • Adjust the height of the nozzle where you want it to avoid further scratching.
  • In some printing software, you can set the height directly through the settings.

Scars on Top of 3D Print - Z Hop on Retraction - 3D Printerly

4. Slow Down Top Layer Speed

Sometimes that loss in precision and accuracy comes down to your printing speed, specifically on the top solid layer and other settings.

  • Decrease the top/bottom printing speed in your slicer
  • Enable ‘Ironing’, which goes over the top layer once over, while a small amount of extruding filament
  • Adding more top layers can sometimes help to give a solid foundation.

5. Change to a Default Slicer Profile

Sometimes there are some settings that have been changed which you forgot about throwing off your 3D print quality.

  • Simply go back to the default slicer settings or a proven custom profile that works

Overall, these solutions will be able to help you solve the problem of having scars or scratches on the surface. Mostly, these are caused by either through the nozzle or through over extrusion.

Follow the solutions that I explained above, and you won’t have a problem while solving the scarring and scratching issue.

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