Fill is ramping / pushing / stacking

Pushing or ramping on fill.

AO-101 with ABS. You can see the perimeters are nice an clean.
Just replaced bushings and tightened all bolts. Noticed this ramping getting a bit worse. Tightened the belts. Belts took in hardly 1/2 tooth. Noticed no difference on the fill after tightening.
Also checked filament with a mic. 2.85. So I changed in slic3r from 2.89 to 2.85. no difference.

Any suggestions?

Also, that is several layers up. The first layer looked like that but not as bad.
That is a .95 fill.
I adjusted to a .85 fill and it is better but it is not showing gaps, looks like a solid fill.
I am assuming my top layers will bring back the ramping issue. (printing now)

; generated by Slic3r 0.9.9 on 2013-11-23 at 19:04:44

; layer_height = 0.35
; perimeters = 2
; top_solid_layers = 2
; bottom_solid_layers = 2
; fill_density = 0.85
; perimeter_speed = 70
; infill_speed = 90
; travel_speed = 150
; nozzle_diameter = 0.5
; filament_diameter = 2.89
; extrusion_multiplier = 1
; perimeters extrusion width = 0.58mm
; infill extrusion width = 0.58mm
; solid infill extrusion width = 0.58mm
; top infill extrusion width = 0.58mm
; first layer extrusion width = 0.70mm

what is your bed heat temperature at? I use 112 degrees with my AO-100. 110 degrees is the recommended setting, but I find the extra 2 degrees really helps for me. The AO-100 used the older RAMPS 1.4 style controller though, so that may not translate directly to the RAMBO style controller the AO-101 had in terms of usefulness. That could be lifting rocking offset. It doesn’t look like a belt shift to me necessarily, but that’s a very large very thin part so it could be lifting easier than normal. You also may want to check the set screws on the pulleys themselves if you didn’t already.

The fact that it is occurring several layers up from the base could also mean that your ACME nuts aren’t free to move in their slot in the X end clamps as freely as they need to be able to. Also check the Z axis couplers on both sides for damage. if those rods are being forced to one side or the other every layer raise, you can get an effect similar to that if the ACME screws aren’t able to deflect to absorb the unwanted motion.

Aside from that, which of the upgrades have you made, if any? The Ao-101 should already have the Y axis belt tensioner, 16 tooth pulley and the lower x clamps in place. The carriage upgrade should also improve stability, that one was released after the last of the AO-101’s were sold so you probably don’t have that one yet. the AO-TAZ mod helps with accuracy quite a bit, but it is complicated to print and install.

Thanks for your suggestions. I actually have an AO-100 with all the upgrades.
I think I solved it with adjusting my starting bed height a bit. I have been using the level bed with paper method. In this round… for some reason I am going with the equivalent a thick paper setting. I ended up whipping out the old bed_calibration_print to fine tune.

I also found that I need to level the hot end a little higher than a single thickness of paper on my AO-100.

I’ve been meaning to buy a dial or digital indicator…