We run several Avengers most with live tooling and they make a lot of good parts but they are starting to show their age. I am constantly working to keep them all up and running. I am always on the lookout for sources of good information and parts. I have purchased one older lathe just for parts and completely stripped it down to the casting (that was very educational and kind of fun.)
I have been to the 850 SX threads and I am dealing with some of the same problems ie. worn out buttons and $$$ cards.

I would be interested in hearing from anybody who has Avengers or knows about good sources for parts. We might even be interested in picking up another one.

Working on 250T I now how you feel.

Nice to hear from somebody Chad.
Working on a 250T??? What are you up to; are you making repairs or just keeping it running?
I would be interested in hearing about your experiences with your Avenger.
I might be of some help if you need any.
I have been working with them for 10 years and have 5 of them, most with live tooling and 3 with subspindles.
I am always looking for information and sources for parts that can keep my operating costs down and keep our machines cranking out parts.
God bless

Trying to keep it running, we have 19 different Cincinnati Lathes and Mills. I am having a repeatability issue with the x-axis. It seems to come and go like a servo problem. I have checked backlash, lost motion between nut and screw, bearing end play on screw and swapped x and z axis encoders as well as swapped the servo board with one in our crib. The only thing i have not swapped is the drive and that is because i dont have any of the 611 drives. Everything else is Kolmorgen or 611U in the Cincinatti machines. I am currently looking for some information on tuning the servo to see if i can adjust it out. Although it is hard to tune something that does not occur all the time. I have spare boards, drives, and crts for most our cincinatti but not this one oddball.

The problem you have sounds like a tough one; and it's always harder to fix a problem when it won't stay broke long enough to find.
You listed most of the things that I would have checked.
Are you getting any Alarm codes or is it just not holding size?
I just had to replace one of our X axis ballscrews this spring, it was worn and had undesirable backlash the problem presented as intermittent chatter.
I would be surprised for it to be a servo problem without popping up some alarms, are you sure it isn't a mechanical issue, maybe even spindle bearings?

What is the drive # you need for your X axis?
What year or serial number is your Avenger?
Check out NuTek on Ebay they have parted out several Avengers and might have the spare drive you are looking for at a pretty good price.