Darker lines and blobs vase mode

[frink 0]

 Hello, can someone explain me why vase mode printed lamp creating some darker and lighter paths (marked blue), only can see when its turned on (adding photos) 

 

Another problem making some blobs (marked red)

 

Im using Ender 3 v2 + cura 4.13.1

 

[GregValiant 1,330]

I get that same effect on every vase that I've passed light through.  The light/dark striations are probably the filament.  Slight variations in diameter, how homogeneous the colorant is mixed, that sort of thing.  Slight changes in the temperature of the hot end as it prints might be involved.  In vase mode the print speed can change as the print gets wider and then narrows again as the layer times change.  If you look at your gcode maybe the "F" numbers will tell you something.

The blobs seem to appear pretty regularly and show up in the same area of each round feature.  They could be a resolution / print speed problem or they could be mechanical and occurring at a point where the nozzle is changing directions and hesitating for a moment.  It doesn't take much of a stutter to leave a mark.

How were you printing (SD card, USB, Octoprint, etc.)?

 

This is from my Ender 3 Pro.  You can see striations in the blue.  The top (it's shoved up into that light) is silky white and doesn't show that problem.  It had ringing instead.  There aren't any blobs on this print.

 

[frink 0]

Im using SD card and have M413 S0 command for gcode

[GregValiant 1,330]

The M413 S0 turns off your power loss recovery.  I don't think that makes a difference.

In the cura Mesh Fixes - what was your Maximum Resolution.  The Enders default is 0.4.  If it gets set below about .3 then there can be stuttering around curves as the printer-planner can't keep up with the amount of gcode it has to process.

[frink 0]

Maximum resolution was 0.25 i changed to 0.4 and now look good (adding photo) 

just now i have some little white holes, but i guess this is filament problem? (marked blue)

 

And still have these lines, but i see pattern is different because i used 200C and this new print was 210C so maybe this mostly filament problem or i can do something about that? 

 

[GregValiant 1,330]

"just now i have some little white holes, but i guess this is filament problem? (marked blue)"

That could be filament or maybe something clogged the nozzle for just a moment.

If you haven't cleaned your nozzle or trimmed your bowden tube for a while then maybe now is a good time.  After printing for hours the bottom of the bowden tube can breakdown (even Capricorn tubing will breakdown) and small pieces of carbonized tubing will break free.  Trimming the bowden back 5 or 6mm may make a difference.  An inspection can't hurt.

If you have not run a PID auto-tune on the Hot End maybe that is something you will want to do.  I'm sure there are youtube videos that explain it.

 

A sort of interesting phenomenon is that the bed heater on Enders is controlled by a thermostat whereas the Hot End is controlled by PWM.  All the current for both of them goes through the mainboard.  The hot end is a pretty consistent load.  The bed is not.

When the bed cools then the thermostat turns it on and when it reaches the set temp, it turns off.  It's "bang-bang" and the current through the mainboard jumps up and down.  That can effect the hot end and so the print temperature can vary.

I added one of these Power Expansion Boards to my printer to move the bed current off the mainboard.  At lower bed temperatures I don't know that it makes much of a difference.  When printing PETG with the bed at 80° it does make a difference.  It requires some re-wiring, but was really pretty simple.  It uses the bed power line from the mainboard as a signal and passes the current directly from the power supply to the bed heater.  That takes the mainboard out of the loop except as the control source.

I'm also hoping to avoid this happening again.