No real need if you do routine care on it!
I break mine down after 24 hours of use...clean it, wipe with oil, unset and reset the tensions, etc....Unless it is acting strange, making noises, or a computer program is not responding...you can do more harm taking it in than leaving it alone!

I took my Viking mega quilter into have it looked at, the tension was not cooperating. It hadn't been looked at for 5 years. My Bernina did go in to a 2 year check up. I called the Bernina dealer and they made an appointment to bring the machine in to be serviced. I went to do some shopping and he called me about 2 hrs later and the machine was ready. I'm in Texas and have to drive to New Mexico for service. Service was 69.00. Good Service and he will do any machine.

I take mine in anywhere between 1 to 2 years, and again if there is a problem. When I bought it new it went in 4 times in 5 years at no charge. Not so often now. I take of the top plate and clean all I can reach, and oil what I can/needed as directed.
The new babylock I am waiting to come in with go for it annual between 12 - 18 months depending on use.

I take my machines in when I go away somewhere as I cannot stand to be without either... :)

Good luck with baby. Sounds like a good plan to me. I'd find it hard to be without a machine too.

I'm with BellaBoo. I clean and oil my machines myself. Mamaw said that oil is the life of machines--and her treadle still works well! Use correct oil-for sewing machines.

I just got my Elna back from repair at my Berninia dealers cost me $34.95 for service and $7.50 for hook repair.

I have a 2005 Viking Rose, and have never had it cleaned either. (I know, shame on me).

I do take out the bobbin, and clean underneath with cotton swabs after each project. Amazing how much lent accumulates within just a short time.

I service them myself.

Depending on the machine, you can do your own tune up ..As long as it seems to be running smooth. I worked in sewing machine sales and the tune ups were basically cleaning and oiling and lubricating the gears if you have gears. ( and yes they charged upward of 100 dollars) There are many blogs on the net telling you what to do. The instructions may be in instruction book that came with your machine. Along with the brush that comes with most machines i always have on hand pipe cleaners (bent they can get into small areas) and new make up brushes along with cotton swabs. Be careful with the swabs tho that you do not inadvertantly leave cotten in the machine.