How to Remove 3D Printed Support Structure

Tips and techniques for removing support material from your 3D printed objects

Removing 3D printed support
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Leaning over can make you fall down. Pretty obvious law of physics, but when you start working with a 3D printer, you don’t always think about it. Until you try printing something with an overhang or protruding part, say an outstretched arm or the brim of a large hat, or maybe a bridge-like distance between two points. Then you rediscover the laws of physics and gravity.

3D printing will require what is known as support. Any object that has an overhang or anything other than a very basic form (think cylinder, block, something very flat, etc.) needs a support element to keep it from falling over, sagging, or melting into the previous layer.

In Tweaking and Slicing for Better 3D Prints, Sherri Johnson, of CatzPaw Innovations, a company that designs and 3D prints scale model accessories for use in Model Railroad layouts, explained how to add supports manually in the CAD program when the model is designed, or by using what she called the repair phase with specialized software, or at the printing phase using the slicing software.

In this post, I want to explore how you get rid of all that support. As you can see in the photo above, there are two objects (both with the Voronoi Diagram or Pattern) and the two red arrows show the most obvious support structures. In these cases, the material largely just broke away when I used my fingers.

I then used a needlenose plier for some of it and a putty-type knife with a sharpened edge for part of it. Lots of people suggest Xacto knives, but even more discourage it because one slip results in a sliced finger and blood on your 3D printed object. Bummer.

The absolute easiest way to remove support is to buy a dual extruder-equipped 3D printer because you can load a standard PLA or ABS material for the primary extruder and a lower-density support material for the other. That support material is usually dissolvable in a chemical water bath. The Stratasys Mojo that I used on the 3DRV roadtrip offered this type of approach. Sweet, but alas it was only a loaner device for the project and, as I found, for myself and others, not always within budget range for the typical consumer hobbyist.

If you are designing your own object or purchasing a finished product through a 3D printing service bureau, such as Shapeways, then you can pick the level of finish you desire, thus having someone else do the finish work for you.

But, most of us are going to manually need to process this support material in some way. In addition to the common sense ways above, here are some more tips and ideas that I gleaned from reading different forums. One of my favorite threads is on 3D Hubs: Best Way To Remove Rafts, Supports, and other Extraneous Filament.

Most of the tips involve the pre-printing stage where you do as Sherri Johnson recommended – add smarter support by way of software: Simplify3D, a paid program, comes up over and over again from the professionals. Freeware, such as, Meshmixer or Netfabb are two mentioned here.

  • When using a knife or scraper of some sort, either heat the model or the blade to make it easier to slice. A tiny butane torch can help (be very careful, for your model’s sake).
  • Sandpaper can work wonders. Taylor Landry, Director of Print Solutions for MatterHackers said that wet sanding with high grit sandpaper – 220 up to 1200 will both remove structure and polish your model. He added “that the best polish we've seen is achieved by tumbling parts in a tumbler using brass wood screws as the media. (Stainless steel can be used on the SS filaments).” So if you are using hybrid exotic filaments, try the tumbler. (LINK LINK to protopasta)
  • With PLA you can get stress marks where the support material comes away from the model and one user suggested nail polish varnish to patch the scratches and marks.
  • If you are up for operating your 3D printing shop like a dentist, get a small drill-like tool called a Dremel. These handheld grinders, with a variety of bits and attachments, can make support material easy. Of course, if you do not have hands like a surgeon or dentist, be super cautious grinding on your easy-to-destroy plastic creation.

    I have a rock tumbler type device that I am going to try as a way to remove internal support structure and will report back.