Hi all, it's been a long time since I've replied to my original post. I worked extensively on developing an easy and effective "ArchiCAD to 3D Printer" process this past summer at the Canadian firm, MMMC Architects. I'll attach the results of one of the prints I worked on. I'll also summarize my findings quickly below. Feel free to ask me any questions, and I can either send videos, text replies, photos to help explain some of the concepts.
First of all, there are many alternatives to this approach that can be better and more efficient. However, they require someone on your design team to understand 3D modelling software such as Blender or Rhino. Nonetheless, what I talk about below is relevant no matter what program you're modeling in.
To go from ArchiCAD to a 3D printer, you need to create a separate version of your model that you know is specifically going to be for 3D printing. There are many great tricks in ArchiCAD to help you do this. Generally, it would be best if you had an idea of what scale you're going to be doing your print to know how much detail to include. It's also a good idea to print a calibration tool. I suggest this one (https://www.thingiverse.com/thing:2975429
). This will help you understand what's generally possible to 3D print on your printer (tolerances, overhangs, etc.) It also helps you understand where you might need to add support in the 3D slicing software. It's generally better to avoid supports, so keep this in mind when modelling. Also, don't be afraid to print difficult pieces separately and reorient them for better printing results. You can always glue parts together seamlessly at the end. By the way, the printer I used was a Raise3D E2 IDEX Printer (https://www.raise3d.com/products/e2/
Once you've created your model, I suggest using clipping planes to crop out small areas and do "test prints." In the example, I use them to equally split the model into 4-8 pieces that attach together. I print the roofs separately. I purposely model a small ledge on the inner face of supporting walls for them to sit on. This technique saves an enormous amount of time and filament. Overall, as I mentioned above, printing the entire model in pieces is the best way to go. Use high-strength clear glue that works on PLA (I recommend PLA for architectural models like this) to assemble everything at the end.
After exporting your files as STLs to your 3D slicing program (there are many out there, but I prefer ideaMaker), you should use the slicing program to visualize where there are mistakes in your model. Then go back to ArchiCAD, try your best to fix it, and then reslice. It's trial and error, but you get good at it quite fast. As long as there are no errors in your slice and there is not unrealistic detail for the scale of your printer's settings, it's safe to say you're going to have a great result. However, always print a small (10-minute test piece first).
Lastly, it's essential to calibrate specific printing "profiles" in your 3D printer for each nozzle/filament combination you plan to use. This process takes time but can easily be done by setting up your printer with the nozzle and filament(s) you're going to use and then printing the "calibration tool" I mentioned above. Examine the problems in each print and tweak your settings to fix them for next time. Very quickly, you'll have near-perfect printer profiles. Use this guide to help you visualize this process (https://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide
I hope that helps, and as I said, I'm happy to help anyone out who'd like to try going from ArchiCAD to a 3D printer.