When was the last time you cleaned and oiled your machine? Or changed a needle?
You don’t remember?
Me neiths.
That’s why I started keeping a mini notebook next to my machines so I could record when and what maintenance I’ve done. 
I change the needles on my sewing machines fairly often, but on my sergers and coverstitch machines? Unless I break a needle, almost never. And when you can take out your handy dandy notebook and see that you haven’t changed the needles in 5 months, it can make troubleshooting go a lot faster.
When it comes to cleaning and oiling, most of my machines suggest once a month… for infrequent use. HA! For “daily use”, the manuals suggest cleaning once or twice A WEEK. *cough* Oops.
Now that I keep notes, though, it’s a lot harder to say to myself, “I just cleaned them, they’re fine….” I can actually look (in horror) to see that they haven’t been oiled in… well, in a long time.
Since I’m a machine freak and have a fleet of machines, a wee notebook is appropriate, but if you’ve only got one or two, you could just use a Post-it note stuck to the back of the machine to keep note.
I just cleaned and oiled my 1930′s Singer.. and I’m fairly sure that was the first time since maybe the 1940′s! Yikes
My baby is very new, only a month old. But I think I’ll give it a clean and oil next week. He was working very hard
Would you say you can oil your machine too often? For example if I’m sewing a bunch of things at once. I get through process 1 and 2 and then oil again before I start 3?(i’m my own assembly line
) just a wonderin’.
I suppose anything is possible, but definitely most people (myself included) are under-oiling their machines. Even with my manual stating that a sewing machine seeing “daily use” should be cleaned/oiled once a week, what they mean by daily use is probably still a conservative amount of daily use- an hour or two. Maybe three. In your case, where you literally might be sewing for eight hours at a time or more, oiling on a daily basis is probably a good idea. I would guess that in a factory setting, the machines are probably oiled several times a day.
I was just thinking that it would be a lot more convenient if they gave an hourly estimate instead. My guess would be that a machine should be oiled and cleaned after 8-10 hours of use, max. That’s a LOT of lint build up.
In any case, with the amount of sewing you do, I’ll bet you have a good sense for when your machine needs to be oiled, so trust your own judgment!