An instructive failure on the Form1

Although this print did not work out, I feel it's important to share it anyways considering it busted one of the resin tanks. Hopefully this post can help avoid similar problems with future prints on the form1.  

The model I intened to print was a 12x12cm 1:800 scale model of a project we designed with our office. It contained the neighbouring buildings of our project on top of a baseplate with a thickness of 3mm, which covered the entire build area.  

Two things went wrong with this print:

1. despite the large surface area supporting the model, it fell off the build platform into the resin tank mid-print due to it's weight  
2. due to a print-time of 15h I had left the printer running through the night, meaning I wasn't there to stop the print when the base fell off the platform into the resin tank.  The laser continued to pass over the same areas which were by then covered by the fallen model.  

Here's a picture of the model. As you can see, only the base was printed before the model fell into the tank.  

Certain parts of the bottom of the resin tank (which is covered in a layer of silicone) are now mirky rather than transparent, in part due to the removal of the model and in part due to the laser passing over the same spots covered by the fallen model. These mirky parts are likely to hinder the laser in future prints, so this tank will have to be replaced.  

TL;DR    If you're not certain that your print is going to succeed and stick to the build platform all the way through, stay with the printer to stop the print in case it goes wrong, and certainly don't leave it running during the night! You might end up returning in the morning only to find a useless plack of resin in the bottom of a now busted resin tank.