3D Printed Architectural Model Part 2: 3D Printing and Post Processing

In the last blog post I described how I optimized a SOLIDWORKS architectural model for 3D Printing. Here I’ll explain the techniques and requirements for 3D Printing and Post Processing the 3D CAD model. I decided to print the majority of the model using mostly FDM, Fused Deposition Modeling – basically the printer will print one layer on top of the previous layer.

Why FDM Technology?

FDM technology lets you choose from a wide range of production-grade thermoplastics, each with specific qualities to meet your manufacturing needs. FDM printers create very strong models and the printed components are made from the same durable material as traditional injection molded plastics. So this was ideal for 3D Printing the base and walls of the model as they needed to be strong and rigid.

Walls of the Architectural Model. You can see the support material which look like cones and overhanging material.

On the left is the first floor and the right is the two halves of the second floor

One of the 3D Printers I used for this model was a Fortus 450mc FDM 3D Printer. The Fortus 450mc can build complex parts faster than it’s predecessors, and offers the same fast build time as other larger machines in the Stratasys Production Series Performance range.

However in order to print the windows I had to use a different technology which I will describe below.

Printing the base of the model on a Fortus 450mc by Stratasys

Completed Base

3D Printing in Multiple Colours with PolyJet

For the windows I used the PolyJet Technology*. PolyJet 3D printers in the Stratasys Design Series can print multiple colours at once. Knowing this I printed the window frames encased within the windows. Not only does this look effective but it also makes the windows much easier to work with when printed. Even though the colours I printed in were black (veroBlack+) and Transparent (veroClear), the printed windows had a translucent appearance.

Post Processing Required

In order to make the windows transparent I had to post process the components. Each window had to be sanded down using a power sander using 150 — 1000 grit sanding paper. Once they were sanded I spray painted them with a lacquer so they appeared permanently wet, improving the transparency appearance. In total this process took 3 — 4 hours between using the power sander and applications of spray paint.

The windows printed sanded and lacquered.

Applying a Custom Colour

Next my co-worker David and I had a very specific colour we wanted to accent the model with, and unfortunately it was unavailable by printing. So we went to a local hobby shop and bought some plain tan colours and when mixed together achieved the “brand new copper” look. After about two hours and 4 layers of paint later the pieces turned out perfect! Now the entire model is ready to be assembled, make sure to check out the final assembly in my next blog post!

Brand new Copper coloured accents for the model

*Polyjet technology prints one layer of material then an ultraviolet light crosses over and cures it to 70%. The next layer is then printed on top followed by the UV light once more curing the top layer to 70% and the bottom layer to 85%. The printer will then place a third layer curing the top to 70%, middle to 85% and bottom to 100% ending the cycle. This will go on for the entirety of the print where at the end the printer will fully cure the model by doing a few UV light passes over top. This creates prints that are very smooth in comparison to other methods because it fuses the layers together rather than adding a layer on top of the previous.

Learn more about PolyJet Technology and you can review the range of PolyJet printers available from Stratasys