3D Printing a Generative Design Model

In a previous blog post, I talked about design a wall hook for my backpack using Generative Design in Fusion 360.  The goal was to then get the design 3D printed.  Now that I have a 3D printer I am able to print this design.  I purchased a Creality CR-10 S5 and this was one model that I used to learn all I needed to know about how to get good 3D prints.

Creality has its own slicer, but I have read that a lot of Creality owners use Cura, which is Ultimaker's slicer and free.  I wasn't sure which one would be best, so I bounced back and forth between the two for a while.  I have since settled on Cura because it gives more options than Creality's slicer.

Cura will take in an STL file that I can export out of Fusion 360.  There are two ways to get the STL file out of Fusion 360.  I can either use Export or 3D Print to accomplish this.  If I use 3D Print, I can send it directly to a 3D Print Utility, I tried this once, but I don't get to save the STL to my chosen location or even name the STL.  So I just save it to a file then load it into Cura myself.  I have also learned that it is best to switch your document units to mm before using the 3D print command.

Export Dialog

3D Print Dialog

Once the STL file is exported, it is just a matter of opening Cura and inserting the STL into a project.  I have used a few slicing programs over the years and they are all pretty simple to learn how to use.  You just need to position the model on the build plate where you want it.  In my case, I had to rotate it so it laid flat on the build plate, which will minimize the number of supports it would need to build.

The first time I printed this model, I realized that it is way too small.  I do have a little bit of an issue with picturing my CAD designs at full scale.  So the second time I ran this, I used the slicer to scale the model 2x, which in retrospect seems a little too big.  I know this wasn't the proper technique.  I just wanted to quickly try it at a larger scale.  The main reason this is an issue is that the holes are twice as large.  I am okay with the scale of the rest of the model, I might have to use washers when I go to actually put this part into use.

When I was going through the Generative Design study, I chose ABS as the material for this part.  That was solely based on ABS being in the material library and PLA was not.  When I bought my printer I bought a spool of ABS and a couple spools of PLA.  The versions of this above were printed in PLA.  The larger one feels sturdy enough to use.  I used PLA to print this for two reasons.  First of all, it was already in the printer.  Secondly, now that I have a printer I have read that ABS is harder to print.  I was curious about which material is considered better, so I did a little research.  I discovered that PLA is actually stronger but more brittle.  ABS is more heat resistant, which requires higher bed nozzle temperatures.  It is very prone to warping.  

After read about the pros and cons of each, I feel that PLA is better for this design.  However, I do have a spool of ABS and I think it will be worth trying to print this in ABS just to see how it comes out.   

Here is a video tutorial that shows the process.