Odd Layer Shifting

DaHai8 · January 31, 2017

I have this odd layer shifting issue I'm noticing when printing in PETG, though I'm not sure its material related (see photos)

The issue is exaggerated in the photos with direct overhead lighting, but you can see that very regularly the layers shift back about .1mm (maybe less) for about 3mm and then shift forward that same amount. Back and forth again and again up the print. The shifting is occuring in the Y direction.

My Y-Axis belt seems tight enough, and I have a belt tensioner on it. But I could try retensioning it, I guess.

But I find it really odd that it is so regular in its occurrence, that if it was a loose belt, I would think it would be pretty random - or always messed up back and forth.

Anyone seen anything like this?

Any ideas what to check?

Thanks!