Typical print quality issues...

Hello fellow Reprappers!

I have been printing for a week or so now, its similar to a mendlemax but different enough to not be one

I'm running off a Sanguinololu 3.1, marlin via prontaface, a Trinity Labs micro extruder and a Jhead hot end with .35 nozzle. All things considered its OK. I am however seeing a wobble along the faces of the prints - I have leadscrews installed.

From some views the prints look good and i'm happy, but turn it upside down or in a different light and you can see a definitive wobble / groove along the face of the print.

Any suggestions? I can only think its mechanical at this point...

Thanks,

Edward

I dismantled the z axis, and notices something with the rods and nuts. Whilst there is little to no backlash, there is wobble or movement if I move the nut left to right on the shaft.

Video of rod and nut.

looks to me like the threaded rod is slightly warped. as to how to fix this i am unsure.

The threaded rod isn't supposed to be providing the lateral stability, it's supposed to be provided by the smooth rods.
Short of very expensive precision nuts, you'll see some movement between the nut and the threaded rod.

What matters is how that slop is taken up, ideally any flex or slight bend in the threaded rod isn't translated to X/Y motion.
Are the threaded rodes constrained at both ends? - this can cause issues
What size smooth rods do you have on the Z axis? - bigger the better so they control the Z path
What sort of bearings in the XEnds? Igus bushings don't tend to be very good
How do the XEnds hold the bearings? - any slop will allow the screws to move the axis

I recently completed a Prusa build. I noticed that the x-carriage had a slight front to back wobble. It is clearly caused by slightly warped Z axis rods. In this case, I want some play between the nut and rod so the motion isn't translated to the carriage (as Polygonhell mentioned). I haven't printed for more than 2 days so far becuse my hot end PEEK isolator melted (waiting for parts) but the parts that I've printed so far do not seem to show any signs of wobble. When I'm up and running I'll look into it more. I may decide to cut new Z-rods (a pretty easy fix).