Different Settings for Different Regions of a Model

weeble2Today we are going to teach you how to use different slicing settings for different regions of your model. This is a unique feature of the Simplify3D Software and it gives you the power to configure the perfect settings for every location on your part. It also opens up many interesting possibilities such as varying density, changing mechanical properties, or even different surface finishes. A great example of how we used this technology is the “Gnome Weeble” model by cerberus333.

When we printed this model, we were able to configure the bottom spherical section with 90% infill density and 5 perimeter outlines. This created a very strong and heavy base. We then printed the top gnome section using a 10% infill density with only 2 perimeter outlines. By doing this, the base of the model was heavily weighted which allowed the weeble to rock back and forth on a table without falling over. Weebles wobble, but they don’t fall down!

3DKnotTo explore this process further, we are going to look at another common digital model – the 3D Knot. You can download this model from user MakeALot here. The model has a flat square base supporting the curved knot model on top. This is a great example of a part that could benefit from two different settings – one for the base and one for the knot. The curved knot on top has very gradual curvature without any significant overhangs. We could save a lot of time and plastic if we printed the curved section hollow with 2 or 3 perimeter outlines. On the other hand, the square base should not be hollow because the entire top surface of the platform would be unsupported from below. We will need to print the base with at least 20% infill, but there would be added benefit by printing it with a large coarse layer height since the square sides do not need a fine resolution to achieve a good surface finish. We’re going to show you exactly how to do this in the Simplify3D Software, so download the 3D Knot STL file and let’s get started!


Configuring Different Settings for Different Parts of the Model

FindCutImport the model into the Simplify3D Software. Feel free to scale and position it as needed (if you need help, please read our Importing and Manipulating Models tutorial). We will be configuring two different FFF settings, one for the base and one for the knot, but first we need to determine where the transition between these regions takes place. One of the easiest ways to do this is to use the cross section viewer built into the software. This will allow us to slice the model in half to look inside it and then move that slice plane to find the exact location we are looking for. You can find the cross section tools by going to View > Cross Section. We will want to move our slicing plane up and down along the Z-axis, so make sure the Z-axis radio button is selected. After you have done this, click to turn on the Enable Cross Section option. To find the exact position of the base-to-knot transition, move the Z-axis slider left and right to move the virtual slice plane up and down. We want to position where the square base ends and the knot begins. In our case this location was at 5.53mm. Make a note of this number. We will need it later.

Replacement pic-StopPrintingAtHeight.pngNow that we know where the transition between our two regions will take place, we can start configuring our FFF settings. Add a new FFF process and call it “Bottom Base” so that we know it will refer to the lower section of our model. Configure the FFF settings exactly as you want them for the base of the model. You might want to click the Show Advanced button in the bottom left of this window if you have not done that already. We chose to use a single layer skirt to prime our extruder, 20% infill to make sure the top of the platform is well supported, and 0.3mm layer heights since the vertical sidewalls can be printed very quickly at this setting. Once you have everything configured how you want it, click on the Advanced tab and look for the Layer Modifications section. You should see two options in this section labeled “Start printing at height” and “Stop printing at height.” These are the options we will use to constrain a single FFF process to a specific region of the model. In the case of our “Bottom Base” process, we want to STOP printing at a height of 5.53mm. Enable the “Stop printing at height” option and enter 5.53mm for the location. Once you are done, click Save so that we can start configuring the second process.

We will be repeating this exact same process for the top section of our model. Add a second FFF process and call it “Upper Knot.” This process is going to start printing several millimeters above the build table surface. It will start where our first process ended, so disable rafts and skirts for your second process (they would only be used on your first process which is flat on the build table). For the remaining settings, we used a finer 0.15mm layer height to achieve a smooth surface finish and set the infill percentage to zero so that this region would be printed hollow. We selected 2 perimeter outlines, and 3 solid top and bottom layers to ensure sufficient wall thickness and a nice exterior appearance. ReplacementPic-StartPrintingAtHeight.pngNext, return to the Advanced tab and look for the Layer Modifications section. This time we will be using the “Start printing at height” option. We want this process to start printing at 5.53mm so that it picks up where the first process left off. Enter these values and then click Save.

select processesNow, you are ready to click the Prepare to Print! button to generate the printing instructions for our multiple FFF processes. When you click this button you will notice a new dialog that appears asking what processes you want to use. In this case, we want to “select all”, which will include the “Lower Base” and “Upper Knot” processes.

We also want to use a continuous layer-by-layer printing mode to merge the two processes together. After you click OK, the software will intelligently merge both of your FFF processes together to create the perfectly tuned settings for our model. It’s that easy!

MergedGcodeAfter the preparation is complete, you can look at the build preview to ensure that your settings are correct. You can use the same cross section tool we described earlier in this tutorial if you want to look inside the line-by-line preview. You should notice that the base of the model is semi-solid while the top is completely hollow. The layer height is also much finer for the top section resulting in a very smooth surface finish. By optimizing our settings for the different regions of this model we were able to save about 20 minutes of printing time along with half a meter of filament! For larger prints this could easily save multiple hours of printing time and pounds of plastic, which makes a BIG difference!

In our simple example, we only changed a few select settings like infill percentage or layer height, but the software gives you the power to change literally every single slicing setting in the program, making the possibilities endless!