Y Axis waves

I can't seem to get to the bottom of my printing issues. I'm confident I've adjusted all the mechanical parts and have made sure everything is tight and sliding well. The steppers are running at the lowest possible current and have slowed the printing speed way down.

I have a Prusa i3
Geared extruder with an E3DV6
Using lead-screws
The model was printed in Polymax PLA at 200 deg, 0.1 layer height with a 0.4mm nozzle.

There are a lot of things that can cause that type of problem.
Slop in the X, Y, and/or Z axis motion- play in the bearings that allows the nozzle to move a little.
poor (bang-bang) control of heated bed temperature
bent Z axis screws
overextrusion

Start here: [reprapmagazine.com] see page 29...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
bent Z axis screws

and/or have them fixed at the top and/or have a rigid coupler with the motor...

Edited 1 time(s). Last edit at 03/07/2016 10:23AM by Frans@France.

I have some flex tubing with printed bolt clamps to hold it to the screw / motor. It seems to work well. A loose belt will do this, but first try a print with the heated bed off. If that is still messy than tighten your belts (not too much). Can we get a picture of the printer? Specifically the Z axis?

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Master Tinkerer

Thanks for the suggestions.

The belts are tight and I don't see any slack in the X/Y movement. I'll try printing with the bed off and see what happens.
I have attached some photos of the z axis.

It does over extrude, I've had to wind down the extrusion multiplier to stop my prints bulging. It now extrudes 85mm when I set it to extrude100mm of filament.

Edited 1 time(s). Last edit at 03/07/2016 03:46PM by bananas.

Unfortunately turning the bed heater off made no difference.

The Z axis should't be coupled at the top.. This means that there will be pressure on the X gantry. If it was left open, the motor and gantry would be free floating, as the movement would be left to the top.
Still, Z wobble simply couldn't cause ribbing of this magnitude. Have you tried another batch of PLA? As a second thought.. Are the x gantries leadscrew couplers loosen the leadscrew? Do they have any side to side slop? I don't know much about leadscrews, but it seems like threaded rod are self-centering as the profile is triangular.

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Master Tinkerer