ripple in flat surface

Hi all. Would anyone have an idea on why I am getting a ripple effect across at flat surface. The model file itself looks fine in my 3D program.... an nice flat surface. Please see attached image. There's also a line across the surface which may not be so obvious but have no idea why that would be there as well. Thanks.

Z-Suite 1.10.0, Z-ABS, 019mm, Quality High, Medium Infill, Fan20, Support 20 (although none generated). I used 20% fan as I was worried the part might warp. Could this be the issue?

STL and ZCODE pls ;) 

Hi Marcin. I'll try and track it down.....Ive not been the most organised with this one. 

How many top layers did you use? I saw these effects, when I used not enough. Especially with less infill this could be a problem.

I see the same on big flat surfaces om my M200. Very little effect if i add more top layer. Must be something else....

I am not sure if it was the fan speed, but I did put it on auto for the next one and no ripple. Top layers at default. I can not find the project file or zcode so unable to say for sure what my setting were.

I believe that could be caused by faulty FANs, cant do much without STL :(

Hi

You can have this one, same problem.

Brand new M200 toplayer problem. If printing in 0.29 it look real bad.