Banding on tall parts

[BPisLife]

As promised I am going to keep this updated. I completely tore down the printer and put it all back together. In the process I replaced the flat style T-nuts that anycubic use with traditional ones as the flat ones can slide over time. I say this because I noticed a 1mm gap in one extrusion to the corner bracket that wasn't there before. I realized this as I found the top of the circle that had a flat spot that aligned itself with the Y tower. Maybe all the work to swap the PCB with the Duet WiFi I moved it. In any event I squared everything up and replaced the corner brackets with metal ones from RobotDigg.

Here is a picture of the progression. The bottom was with old belts and pulleys, middle is with new belts pulleys, and the top is the latest. You can see it is a lot smoother, but I still can't figure out the banding.
Top picture is the base and the bottom picture is of the top. The bands vary with print time. The first two rods had infill with the latest being printed in vase mode.

[dc42]

Are you using PID or bang-bang control of the bed heater?

[BPisLife]

@dc42 PID. I am convinced it is the bed. What do you use on the delta to hold the build plate. This printer came with plastic holders but I wonder if they have warped over time as I have been printing with nylon so needed that bed hot.

[BPisLife]

Finally, I get to close out this post!

The thin banding in previous pictures went away with the frame rebuild. The thick banding went away when I tightened the bed's feet up against it so there was no chance of movement.

The result, a perfect print with no banding.

[T3P3Tony]

@bpislife starting to look very good!