I’ve bumped into a very interesting technique that could save an enormous amount of support material and 3D printing time.

Support structures are an inevitable aspect of 3D printing: some geometries are simply not capable of being printed without support for overhangs exceeding the threshold of your device. Typically this ranges from 45 to 60 degrees of inclination. 

While some models may require minimal support structures, others require enormous amounts of support for huge overhanging sections. These supports require not only time to print and a large amount of eventually wasted material, they also require manual labor to remove them from the print once completed. And they mess up the surface finish, too. 

I really hate support structures and try my hardest to not use them unless absolutely necessary. You likely feel the same. 

One of the reasons support structures take up so much material is that they’re most often generated in a very simple matter: if an overhang exists, drop a support structure vertically to the bottom (or other intervening layer). This simplistic approach can generate a ton of support material that is surely wasteful, particularly on larger objects. 

Optimizing 3D Print Support Structures

It turns out there is a very unusual approach for dramatically reducing support structures in some geometries. This technique is available in Simplify3D, a third party commercial slicing software option. 

I’m not sure it is available in other slicing tools, which tend to use “support enforcement” or “support blocking” concepts that can sometimes reduce support. The Simplify3D technique, however, can offer more benefits at times. 

Here’s how it works: While Simplify3D can generate support structures in the same vertical manner, it is possible to rotate the 3D model after they are created!

Let’s walk through an example to see how this could work. I’ve created a pathological 3D model in Autodesk Fusion 360 to illustrate how the technique works, which you can see at top. This three-way arch could clearly be printed upside down without support, but for purposes of learning, let’s attempt to print it right-side up with minimal support structures. 

If we were to simply ask Simplify3D to generate support structures automatically, this is what we get:

You’ll note there is a tremendous amount of support material used. This 3D print is reported to take 172 minutes to complete, and consume 38g of material. 

Now let’s use the optimized process. You simply rotate the 3D model to expose the area that requires support and manually build supports from that that spot down to a convenient and nearby wall. While Simplify3D thinks it’s building supports vertically, we’re going to rotate them later. 

Depending on the geometry of the 3D model you may have to rotate the model several different ways to place supports in all areas requiring them. In this case I needed only three rotations to finish it. 

This particular 3D model is “open” and it’s easy to view what you’re doing. It’s a bit harder to do if the 3D model is “closed”, like a hollow sculpture of a head. But it can be done. 

This is the final result of my manually added supports when the model is rotated to its final position. 

When slicing this version using the manually generated supports, there is quite a difference in print time and materials: only 105 minutes and 20g of material. That’s a savings of a whopping 39% in print duration and 47% in support material! 

I intend on using this approach going forward to substantially reduce support material and print time on suitable 3D models. Will you try this, too?