Hello David,
When you write, "[w]e tried saving to a PDF, but we're unsuccessful using that approach as well", do you mean that the creation of the PDF failed or that printing of the resulting PDF fails?
Could you try the following procedure?
For each Graphics3D output cell:
a) select the cell bracket
b) invoke the menu command Cell -> Convert To -> Bitmap
Attempt to print the notebook.
When printing a page (or generating a PDF through the Print dialog), Graphics3D output is rasterized at the printer resolution (usually 600 ppi). This may exhaust the memory on the lab printer. The procedure above rasterizes the Graphics3D at 72 ppi. It will produce much smaller image sizes at the expense of print quality.
Please let me know how this turns out.
Thanks,
Chris