5 Quick Tweaks that Will Guarantee to Save Your 3D Print Time
When slicing models to 3D print, we have to balance two opposing factors: the speed of a print versus the quality of the finished part. These factors are not always at odds; with advanced techniques it is possible to dramatically reduce print time while still maintaining excellent quality.
For this demo, I will be using a pattern which might be used for sand casting or other molding applications. These types of models are particularly well suited to FDM printing, as draft angles and minimal overhangs make for trouble-free prints.
I will start using the basic 3DP workbench profile and then explore two techniques in Simplify3D to optimize print time, starting with infill.
Print time on default profile (15% infill, .2mm layer height): 82 hours
We are all generally familiar with infill percentage, but may not be aware that infill may be kept very low, on the order of 10-15% for most common parts. It can be tempting to bump up the infill percentage for a stronger part, however the benefit is minimal in most cases.
The second setting to be aware of is infill pattern. The speed will vary only slightly, but honeycomb will save us a few minutes over Grid pattern.
The next step will maximize our time gains, if using small layer heights (.2mm with a .6 nozzle) we can direct our infill to print only every other layer (.4mm infill layer height). This will cut our infill time in half, and will result in dramatic time gains for large parts like our test model. In the Infill tab of Simplify, change “Print sparse infill” to every two layers.
Notice how our infill (orange) is twice as thick as our perimeters (blue & light blue) This saves significant time; we are essentially cutting our infill time in half without no loss of surface finish.
The final step toward optimizing infill is to ensure that the infill is running at the maximum allowable speed. If we are using .4mm infill, we can run it safely at 70mm/sec. Go to the “other” tab in Simplify, and set the infill speed to 100% (to match print speed of 70mm/sec)
Print time with infill optimized: 56 hours
Once we have optimized our infill, we can leverage the power of multiple processes to change our settings as we build our part.
Set up two or more processes, in the Advanced tab, set process 1 to stop at a certain layer height, then process 2 to start at the same height. After this initial setup, we can alter layer height and any other settings mid-way through a print.
Once we have multiple processes set up, we can easily change the layer height and resolution of each process, optimizing speed for each area of the model. In our example, we print the base of the model with low resolution, fast layers. When we reach our lettering we want a finer finish, so we drop the layer height down to .2. The profile of the part when printed will look like this:
Notice how the layer height changes from .4mm to .2mm to preserve detail
In our mold example, we can print the base of the mold using thick, low resolution layers without an issue, however when we get up to the text itself, we drop the layer height down to ensure our letters get a nice finish. Once the lettering is finished, we return to .4 layers for the remainder of the part. This optimization takes a little time to set up, but it will save a good amount of machine time on larger prints.
Time of print with process optimization: 53 hours
There are innumerable tweaks we can make to our process settings, but starting with these two will result in significant time savings without any significant loss of detail.