How often do you have to service your Studer or Otari deck ? Home not pro environment.

I have a Crown CX-822 reel to reel. I bought my unit from Chuck Ziska, Crown engineer that now refurbishes them. I haven't had to service it yet. BTW, I am not sure there is anything to service other than cleaning the heads. 
To answer your question, tapeheads.net is a great resource. There is a very well respected technition in Los Angeles that works on Studers. I don't want to post all his info on a public forum, but if you PM me I can give it to you. Or you can get an account there and quickly you will see who it is. Once again I never used him, since I have a Crown, but I read his posts and others seem to be very happy with his work. 
BTW, I really like the ATR MDS-36 tape. I just bought one sample and evaluated my recorded frequency response on 7 1/2 IPS (my go to speed) and I thought for my deck it was better than the Pyral. YMMV.
Typically, as far as I understand, and reading through the Crown maintenence manual, other than cleaning the heads there is not much to do , for the amount I actually play the unit. That's if your unit is in prime shape when you acquired it.

Should have said:
"Other than cleaning the heads and setting tape bias for the different tapes"

captain_winters, thank you. I don't have open reel deck yet, this is my future project and it will take time. I am just gathering information and opinions regarding what might be involved in using those pro machines. Otari is more likely for me than Studer because of the cost.
How do you like Maxell back coated tape ?

I only use new tapes. These are the 3 tapes I use. 
RMGI/PYRAL LPR-35 (1mil tape)
RMGI/PYRAL SM-911
ATR MDS-35 (1 mil tape)

I have one sample of the MDS-35,  but I really like it, frequencies record very well on that tape from my Crown CX-822.

For those curious, there are 1/2 track and 1/4 track. All 1/4" tape.   So 1/2 track means that 2 channel stereo is all on the tape, then entire 1/4". So approx 1/8" for left channel, approx 1/8" for right channel. This is what is used for master recordings. The majority of consumer units were 1/4 track. So each stereo channel, right is approx 1/16" and left is approx 1/16", so stereo takes up half the tape. That is why you can turn the tape over and record on the other side. Just like cassette. Since the magnetic flux density is not as high as 1/2 track, 1/2 track is always used for the highest fidelity master tapes. Sometime people also call 1/2 track, 2 track and 1/4 track 4 track. In fact the commercial tapes produced back in the day actually had a 4 on them for 4 track.

So before you buy consider the following:
1. 1/2 track or 1/4 track?
2. Tape speed options? I like 7.5 IPS and 15 IPS 1/2 track.
3. Get a deck that is actually servicable. Some Japanese decks noone will service, there are no parts available. Typically Studer, Revox, Crown are servicable, there are others as well.
4. I use my deck for recording my album's and playing them back for longer play while not critically listening. Since I get 1 hour 36 minutes from 1 mil tape.
5. I wanted the best sounding deck, I can A/B the album and tape during recording since my deck has read after record and I am hard pressed to tell which one is which. Hence 1/2 track 7.5 IPS.
6. Tape heads.net is a great resource. 

Inna
re the Studer,
Once it is setup it is pretty dependable (knock on wood); keep the heads clean. Use good tape.
I will say from all my time with my Studer the following questions need to be answered when looking for one. A Studer is really no different than buying an older Porsche.  
Serious questions need to be asked.

Do you know the person you are buying it from and its history ?
If it was not maintained by an authorized Studer tech I would not look at it further.
If buying from an unknown source you will need to pay to get it calibrated and set up properly.

**The tech needs to be within driving distance - forget about shipping it. It can get bumped and parts put out of alignment. I experienced this when mine was shipped to me initially. That is how I was introduced to Roger Ginsley - Studer Tech Rep for Canada. 40 minute drive from me. Talking with other tape guys in the past they all say the same thing - you are so lucky to have a Studer tech close by. Picture 5 in my virtual system shows a pic of Roger working on my deck.

***************************************

Let me tell you a story that happened many years ago.
I went to play a tails out tape. It powered up like normal.
I wound the tape up and hit rewind to bring it to the beginning.
Nothing - just a click.
Talked to my Studer tech Roger who assumed the power supply capacitors needed changing.
This was at a point in time, when I really needed that deck for audio fixes. It was my reference. It had to be repaired.  

So I drove it to him. He pulled the two main coke can size Made in West Germany silver capacitors.

Guess what ? they tested like new. In impeccable condition he said.
I then asked him.

Are you going to change them out anyway due to how old they are ?

I forget the brand name of the capacitors he had sitting on the table waiting. They would have been the best of what was available then.

He said no. They don't make them like that anymore. He refused to change them out.

That repair cost me from what I recall about $300. All labor. It took him a few hours to trace the problem to a faulty resistor. The manuals he was using to find the problem were 5 inches thick.
Have you seen the way the circuits are built and laid out in the Studer ?