I have machines that run with the lights on, but overnight often.
(most of the time if I had my way)
But i will say - I would not employ a practice of not checking parts during the day - simply b/c you won't tonight.
Once you walk away from that machine, the next part could be junk, and it could run till the magazine is empty. This can happen when you are standing 10' away just the same. Once you walk away - you take a risk of running junk, but if it is unatended, you are only risking material and tooling, and whatever electricity, coolant, and perishables as well... 3rd shift is always a gamble. Don't risk more than you are willing to lose....
It is best to change all needed inserts or whatnot soon before leaving so that you are walking away from a sharp machine that will have less likelyhood of having issues. If your tool will run all day - let it be at the end of it's life while you are there. (and checking parts every so often)
Some jobs I leave run all night. I have already left a known job run for [what should have taken] 32 hours when I left for a trade show for the weekend. I knew that it would be on the ragged edge of wear on a tool or two, but the last part was still OK.
Other jobs I may set the counter to stop in 2 hrs, 4 hrs, or whatnot... Just depends on the job. Example - a job with single pointed threads I will likely not leave run all night. But I might leave it run for 4 hrs. ???
You say your ina Swiss:
Are you running coolant or oil?
If you are in oil, the first thing that you want to doo before walking out the door, is to employ a "Firetrace" system. (I need to take my own advise on this one yet)
http://www.firetrace.com/english/applications/industrial/?page=cnc-machines
I would reccommend starting with setting your counter for a few hrs and werk your way from there.... Or only put in two or four bars in the magazine, or whatever means you want to use to limit production qty...
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I am Ox and I approve this h'yah post!
Ox