Printing defect on Monoprice IIIP

[ABaker]

i have a monoprice IIIP printer, it works great except for this one constant defect that all the prints have, they all have a rough texture in the form of ridges parallel to the layers. i really want to know what could be causing this. they are very uniform and constant, part is about 26x17mm
cropped defect 1.jpg
cropped defect 2.jpg

[curious aardvark]

Hmm, on an i3 it wouild be a misalignment in the z-axis screws or extruder carriage that causes it to swing in and out as it travels vertically.

That looks like what is happening here.

If you video the printer moving fully down and then fully up (without printing), you should be able to see the extruder carriage swinging as it moves, or the x-axis arm dipping and rising. Try speeding the video up to make it more obvious.

So as you only have the one z axis screw.
It could be a misalignment in the screw coupler, or the carriage that attaches the x-axis arm to the screw.

It could also be the x-axis arm dipping towards the ground, which would be down to the bracket assembly.

But the video of full z travel up and down and then played back at speed should give you a pretty good indication where the problem is.

But basically it's a mechanical misalignment on the z axis setup somewhere.

[3DPrinterMan1234]

yeah try tightening the z axis screw