Print quality varies with direction

This very well may have been previously addressed, but I couldn't find anything on it. (Maybe I'm wording it weird.) Anyway, I've been printing for a few months now using the following:

1.75mm filament
budaschnozzle 1.1
Makerbot ABS
heated bed with kapton tape and hairspray as addl adhesive
Decent quality hobbed bolt & grooved idler bearing
print height anywhere from .05 to .3

Quality has been hit or miss in some situations however. It seems that I can get nice clean vertical faces of parts, but only when the print head is traveling in certain directions. For example, if I print an object with two faces oriented at 45 degrees from the x direction I get one face with nice quality and the other with rough surface. It appears that if the nozzle is moving in the positive x and positive y direction simultaneously, the quality suffers for some reason. On the other hand, if the nozzle travels the same 45 degree path in the opposite direction (negative x and negative y simultaneously) the quality of the surface is beautiful. Of course, this isn't limited to 45 degree paths specifically, but the problem appears when the direction is in that neighborhood. I'm having a little trouble getting the problem to show up in pictures - probably because I've been printing in black, I'll try to add some if I can get it to work.

Is it possible this could be an indication that the nozzle is not perfectly normal to the print surface? Any other ideas?

I have noticed that when it is a normal Cartesian movement (all X or all Y) the print is usually fine with mine. BUT When using 2 axis at the same time I would have issues.

Here is some of the things I found that helped with my issue but not having a picture to look at I am just shooting in the dark.

1. Loose belt. My belts were not loose enough to be noticeable to me when I was running a part but the combination of axis made wobbly results (layers stacking on one another not fully aligned).
2. Too much carriage friction on the smooth rods caused some issues. Lubricate and look for parallelism as much as you can between the smooth rods.
3. Idler pulley size. Make sure you have at least 3 belt teeth fully engaged on the pulley when running. I ran across a good write-up here about this subject here but for the life of me can't find it for you at the moment.

4. This is a longer shot. Z-Axis wobble or bend in the threaded rod. I am current working on a fix for my X-Ends to eliminate any by allowing the nuts and the holder for them to 'Float". That way the nuts on the threaded rod and the nut holder will only be used for lifting and lowering. Alignment will be left to the job of the smooth rods as intended.

Hope some of this helps.

Mike

Similar problems happen to me. Xcarriage moves smoothly going left and wiggles a bit while going right, Y bed moves smoothly going away and wiggles a bit while moving forward.

What helped me was retightening the belts, adding extra bearings on the X carriage, relubricating the whole thing, using thinner and lighter glass on the bed, retightening nuts around the base was a big help and using an X assembly with less weight and more centered weight. Still having problems, but all this helped.

Posting a picture of your prints will help us. Also what printer are you using.

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-Tom