Speeding up a 3D Print with Chamfers

A section view of a hollow part that will need
a lot of supports to print  successfully
Model created in Fusion 360

When I first started 3D printing, I had quite a few assumptions  in my head.  One of the first assumptions I had to dispel was that if the model was finished in CAD, it was ready to print.  There was no such thing as optimizing for 3D printing.

I was quickly learned that like many projects, preparation can be a huge part of making sure a you can get a print in a timely matter, and optimizing for 3D printing was a very real consideration indeed.

One of the things I've found I modify a lot are the hollow internals of the part.  That's right.  Sometimes the portion of the print nobody ever sees gets the most attention!

If you're like me, you might think "Who cares what the inside looks like?  Nobody sees it."

The rub comes when considering 3D printed models need to build a lattice work of supports to hold up overhands that would otherwise collapse if left unsupported.  That lattice work takes time and material to create. 

The supports (generated in Cura), can be seen in cyan below.

The required supports for this build.  That's a lot!

And what that translates into, is a lot of extra time and wasted material as tons of supports get generated.

So what can you do to reduce the internal supports for  model?

Build your own!

At least in my experience, I found that the threshold where the slicer adds supports is 45 degrees.  If an overhang is 45 degrees or more, it will "self support".  So by adding 45 degree chamfers into the hidden overhangs of a model, the amount of time, and material needed to print a model can drop way down.

In this example, 45 degree chamfers removes the need for supports
(Image from Cura)

In the prints I've made, I've shaved about 30% off the time to print a model.  In one case, I saved 10 hours from a multi-day print.

Of course your results will vary, but the real lesson I'd like to share is that sometimes, you may find that it's better to make modifications to your model in your preferred CAD system before throwing it at your slicer and letting that go to town.

So think about altering the internals of your models a little to remove unnecessary material.  Something as simple as adding big chamfers to overhangs can make an enormous difference in your print times and material costs!