I've got an issue with printing a large part on glass bed. The material i'm printing has a very high coefficient of thermal expansion (higher than ABS), and is pretty difficult to persuade to stick to the bed as well.
I've solved the bed adhesion issue at this point with some consumer products, but the issue I'm having now is preventing my printer from shutting down after the print. When it shuts down the part shrinks as it cools and shatters the bed. My current solution to this is to be at the print when it is done, and squirt it with some isopropyl alcohol to dissolve the glue that holds the part to the bed, and the part pops right off.
The print time on this part though is about 20 hours and I can't be there all the time to catch it as it completes the print. I would like to include some G-Code at the end of the script to keep it heated and to not turn off when complete. My current way of doing this is to use an M140 command to set the temperature I would like it to stay at, and then use a G4 command to wait until I come and end the script manually. Having tried this yesterday though, I came back to a shattered glass bed and am looking for another way to do this, as it seems the auto shut down ignores the wait time before turning the printer off.
I'm sure there is a dozen ways and commands I could use to keep the printer from idoling and turning off, but I wanted to see if anyone had any recommendations for this.
I am using a creatbot f430 so customer support is cumbersome to go through, and I haven't been able to access the firmware (I haven't tried super hard) to prevent this from happening. I'd like to be able to do this all from the slicer though if possible