Odd print effects

I’m making this odd toy part that’s is 12mm wide and 55mm tall, and my first print on my Taz5 came like the photo attached. I’ve never seen a pattern like this (granted I’ve never had many issues with prints on my machine – at least nothing that required me to post on this forum). But the right side of the print model is impeccably smooth, and the left side is… well ringy… It’s positioned vertically on the bed as I know it can’t print horizontally, and it’s orientation on the bed is perpendicular (as in the right side faces towards the user and the left side faces away while it is printing.)

My print speed for this tiny object is 10mm/s (where larger prints have been 40mm/s), minimal layer time is 20, and outer shell speed was 40 and inner shell speed was 30. I printed at 0.1mm layers.

All bands are very tight, and I print on a level table. Room temperature is consistent.

Based on that information I would really appreciate anyone’s advice on sourcing the problem and offer an solutions. If more information is required, please let me know (and if it requires code, please direct me how to source it so as I can post it to be read.)

Much thanks.

Several things can cause one side to be worse than the other:

Airflow/cooling on that one side could be worse. Since it’s a fairly narrow print, there may not be enough time for the layers to cool properly. If you’re using the stock Taz 5 head with cooling on the one side only, the less cooled side may not be significantly cooled.

Higher-temp plastic stuck in the nozzle. There could be a small chunk of ABS/Nylon/HIPS/whatever inside the nozzle that’s impeding flow. A cold pull can help, or just running some cleaning filament if you keep it handy.

Slight deformation of the nozzle. If the nozzle is slightly out of round (possible damage from being used as a probe against hard washers, for example), one side of prints would be uglier than the other. If the left side of the inset portion is also ugly, that would be a clue it’s this.

One Z-axis motor is missing steps during print. The bed leveling can hide this, by correcting for some slippage either way each time it levels, but if during the print it’s losing a step or two on the way up, and missing that same step on the way down, it still appears level at the bottom of the print, but prints will show squish on one side. If you’re seeing this much irregularity in 12mm though, it would probably be pretty pronounced at the edges and be visibly un-level. Either way, it’s easy to check by putting a small block (about 40mm tall) on the bed, directly beneath the gantry on the left side of the bed, and slowly lowering the z-axis until it almost touches the block. Slide the block out and see how it fits on the right side. If it doesn’t almost touch, disable the steppers in the motion menu, then manually twist the threaded rod on the right side until it almost touches the block. Re-check on the left side, and make the minor adjustments there if needed. Once you’re convinced the gantry is level to the print bed, raise it and lower it using the motion menu a half dozen times and re-check with your small block. If it’s no longer level, there’s a problem with the motor or driver.

This is great! Thanks. I will start that troubleshooting today. Much appreciated.