non 2mm VFA

[megamandal]

I went through the vfa numbers of times, my IS graph was very bad, after almost 2 years running the 2.4, I start to get non 2mm ripples. I can hear the rails are making more noise, I replaced the balls on all rails, but they were great, it did give some improvement, also replaced belts with genuine gates 2gt 6rf, that didn't do much, initially I had VFA on all directions, after working on the rails, the ripples then only happens on A if I print wall clockwise, or only on B f I print wall anti clockwise, with very little, hardly noticeable remains on X and Y, I then replaced all 3 rails with genuine Hiwin MGN12H, replaced motors with LDO-42STH48-2504AC speedy motors. before I replaced the rails, for some reason, the B belt keep getting stretched more, as when I reinstalling the old rails after replacing the balls and retention the rails, the B belt needed a lot more turn, I am waiting for new belts to test again, if it does the same, when it was built at the start, there was none of these issues, after replacing with hiwin, the layer lines stacking up very much perfect, compare to before, completely perfect cube with x and y walls spotless, but cube printed 45deg has ripples, but much further apart than before, about 5mm from corner starts and 5mm before reaching next corner, on both A and B path.

only thing I haven't replaced are the plastic motor mounts and f695, all rails and mounts are abolutely solid, when running IS, there was very much no vibration noise other than just before 50hz, but the adxl was getting error on axes mapping with Z, when running IS on Y, its picking up noise from Z.

the result also not really any difference than the best I managed with the old parts, X with MZV 58.2 just over 10k acceleration recommanded, Y with MZV 37.4 4090 acceleration, which I think is very low, when I printed the cubes with 4000 acceleration, the ripples are much faded, problably could have them gone with lower acceleration again, cube printed with 10k acceleration, the ripples are deeper and can feel it very easily if you run your finger along the wall.

anyone have any ideas? the guide has got a section for non 2mm vfa on AB but not XY.

thanks