Printing abnormalities (object sources?)

[cyber.shifter]

So, I did some printing over the weekend and had some mixed results. I've attached a few pictures of what's going on.

Object from RoStock library that comes with the machine. Layers printed well, but the weird anomaly is there.

Another picture of the... ? (I have no idea what it is, forgive my ignorance).

A TARDIS I tried to print (from Thingiverse) The layer on top is the where it started messing up.

Another view of the TARDIS that distinctly shows the anomaly.

A smaller version of the TARDIS. Print messed up at the same point (but different build height).

So the TARDIS came from Thingiverse, but the other part was stock in the machine. Has anyone else had trouble with printing things from Thingiverse? The stuff I got from SeeMeCNC seems to print flawless, but I've had troubles with stuff from Thingiverse. Any clues?

[IMBoring25]

Thingiverse doesn't check their uploaded STLs for being manifold and some slicers do goofy things with non-manifold STLs. One of the repair programs like netfabb might help.

[Jimustanguitar]

You're talking about the diagonal stripe that's present in both parts?

The model files came from different places, so it's not that. This looks like a mechanical issue to me. Oil your u-joints and check for spots that stick as you move the arms around.

[KAS]

My guess it the cheap skates or something in the rotating chain ( belts, pulleys, etc) as the line moves uniformly in a diagonal fashion as the layers get taller.

[cyber.shifter]

So I recently adjusted the towers because one was out by half a degree. Then I re-calibrated. That's when I started seeing this. Oh! I just remembered, during the calibration process, I accidentally got my finger jammed in the tower while the skate was moving, but I shut the machine off right away, could that have done something? Also, I'm guessing a light oil like sewing machine oil will work?

[Creator]

Take a look at the belts on all the towers so that you don't have any wear or irregularities on them?
Maybe the servo chewed up some teeth when you got stuck?

[cyber.shifter]

I checked the belt and it looks good. I also adjusted the cheapskates as they seemed a bit tight. The only other thing I can think of is the divot that came in one of the cheapskate wheels. I mentioned this in another thread, but I didn't see it affecting things before so I'm not sure that would be causing this diagonal line. I'm going to try oiling each of the u-joint bushings tonight. I'm guessing I just need to put a drop of light oil on the shaft and not the tabs that snap into the arm?