I had this problem as well, although it was not due to sanding. My problem is that the head piece was much too loose, causing it to fall off unless the whole piece or orientated upwards.
There is one more trick you could use, but be carefull as it can potentialy ruin your print.
Try holding the lips of the head piece under hot watter and gently squezze them together so the get a fraction of a milimeter tighter. This gave the final result for me.
The certification model is just Monica, she is the toughest print to make. Once certified you will receive the final models around October 20 or 21, but test prints for those models should not be necessary unless you would like to conduct them on your own.
thanks for your reply. Sure test prints may not be necessary, but I like it to practice (print and post processing) to be prepared when an official order is placed.
Besides that, collecting all and take a photo of the entire “family” would be fun too
I have printed six Monicas and gave them to my kids to play with for “market research” (ages 9 and 11). The tail keeps breaking off so I would like to propose making the tail removable. It could also have a long and wide base inserted in a hole. Also, the coli should be thicker diameter. So, is it possible to get the CAD file to make the modifcation? In addition, maybe the tail could be customized to different shapes or be the kids name in script font.