Anyone seen this problem?

[GBR1]

Hi all,

Has anyone seen this issue. The banding is very very regular, so much so it looks like its in the G Code and isn't a mechanical issue.

All thoughts welcome though.

Many thanks

GBR1

[dkightley]

Despite very little information to go on and the photos looking as if they're upside down....I'm going to make a couple of suggestions...

It looks as if you're getting good filament flow and then it tails off, and then comes back again..and so on. One possible cause could be a filament feed issue where the filament is snagging and freeing up. Check the filament feed path for possible snag/jam points.

An alternative might be temperature. You might be running right on the lower edge of the temperature range, and as the extruder temperature cycle between heater cut-in and cut-out varies the plastic temperature, the flow rate is varying accordingly. Up your temperature by 5 or 10 degrees.

[GBR1]

Thanks for the info..

So printing with PLA at 230 deg C. 20% infil (honeycomb) with a shell thickness of 3..

Filament flow "looks" fine as the print is solid, no underextrusion. Filament is free to run, I have had poor filament feed before and it didn't look like this!?

The lines (bulges) are very regular, as said so much so it's like it's suppose to be there! They last for entire layers and are symmetrical in the rise and fall.

Many thanks

GBR1

[RudydG]

I had exactly the same problem, in the end it was my heated bed (expanding / retracting)
It was so regular, that i always suspected the Z axe, worked many hours on that.
But after changing my heatbed control (i have marlin based machines) in the firmware, from bangbang control to calibrated PID control, it is alle gone now, the Z banding.
Maybe ???

[kiwisam]

I had exactly the same problem, in the end it was my heated bed (expanding / retracting)
It was so regular, that i always suspected the Z axe, worked many hours on that.
But after changing my heatbed control (i have marlin based machines) in the firmware, from bangbang control to calibrated PID control, it is alle gone now, the Z banding.
Maybe ???

This has always been a bit of a bug for me also. Apart from that I consider I am achieving near perfect prints on my TAZ 4/5.
I am curious to know how you go about calibrated PID control, or perhaps you may be able to direct me to the necessary info.

Thanks

Sam

[loftonharris]

It seems to me that printing PLA at 230 degrees is a bit high. The heated print bed shouldn't be an issue, so long as it's turned OFF. These suggestions are not specific to your problem, but are general in nature. The recommended range for most PLA filaments is 195-220 degrees C. I tend to go between 215 and 220. It seems lots of problems can be caused by excessive extruder temp settings. In my case, it makes my extruder drool like a Basset Hound.