Circles are now Oval - Desperately need some help!

[tamcofarms]

I have been printing on my Rostock Max v2 almost 10 months putting on 750 hours and going through 4.2 miles of plastic and everything has been 'perfect' when it came to things in the round and other shapes. Squares were squares and circles were circles. This week all of a sudden circles are oval. I have gone through calibration 3 times tonight and you know how long that takes, fortunately there was nothing to calibrate the 2 and 3rd time was pretty dead on as much as you can be with using a piece of paper for calibration.
I am at a lost as to what is causing the issue. I can't see anything binding, nothing loose. Belts appear okay as well. It starts with layer 1 and is consistent through the hole piece. The oblong of the oval is always exactly front to back (from LCD towards theoretical 'Z' post).
I am using Repetier and Slicer and haven't had this issue before. Any suggestions would be greatly appreciated. I am working on a piece for somebody for Comic-Con and he is quite anxious to have it done even though he has 2 months to go.
Ted

[tamcofarms]

Also, just to be sure, I used Cura and got the exact same results as I did with Slicer.

[craftymethod]

is there any play (wobble) in your cheapskate rollers?

[guanu]

ok, so you said the machine is about 10 months old? that would put it in metal u-joint times correct? if you have metal u-joints, pop the arms off and check your u-joints one at a time and see if they spin freely, we have since switched to acetyl u-joints to prevent binding, you may have a u-joint that has a metal burr in it and has bound up, so that would be the first thing to check.

Guanu

[tamcofarms]

You are correct - metal joints and one on the 'Y' (right) post was totally bound up. It took some heat (not much) to actually get it off the rod, cleaned everything up, removed and cleaned and lubricated them all. Recalibrated and it took care of the oblong from going from front to back and now going from left to right, just not as bad.
I have just gone through the cheapskate rollers and even though they all appeared fine and no free play I did readjust them for the 'perfect' feel. Getting ready to run another test now.

[tamcofarms]

Still getting ovals. They are running from front to back (was wrong on the direction change). The test model is a smaller cylinder sitting on top of a bigger one. The smaller cylinder is running is size from 12.22mm to 12.44 and the larger cylinder is running 29.80mm - 30mm so the amount of 'skew' seems to be the same regardless of size of circle.

[teoman]

I started getting terrible prints aswell, circles were oval ish, we diagnosed the problem with the help of JFettig.

It turned out to be one of the motors loose. All of the motors were slightly loose upon inspection. So i tightened them all up. (Motor to melamine connection was loose).

Printer is 7 months old.

[tamcofarms]

Realized I hadn't given the final update to resolve this issue. Fixing the problem with the bound up joints and readjusting the cheapskates would have taken care of the problem. However when I readjusted the cheapskates I went the opposite direction with one of them this was skewing the print job. After making sure they were all adjusted the same direction opposite each other and doing a level adjustment my perfect circles were back.