bridge interior wall sagging due to slicer line thickness setting?

[leedav11 0]

I'm trying to figure out why the first layer of my print's interior bridge is falling off over such a small bridge distance (8mm), and upon closer inspection it looks like the inner wall lines are super thin and that's why the printed part have these two lines falling off the print.

 

can someone please help me how to tweek the CURA setting so i can avoid these drewpy lines?

 

 

Edited December 13, 2021 by leedav11

[leedav11 0]

adding some photos of the issue as printed. Note that these are test coupons to dial in the print, the final design these over hangs are enclosed where the underside can not be viewed - so i can't print these with support but again, i think the issue is with my slicer setting not the actual printer setting.

[Torgeir 243]

Hi @leedav11,

 

Welcome in here!

 

First, what version of Cura are you using?

 

The first picture "may" show how Cura show lines when Combing is used, -I'll think.

 

The two latter pictures, looking from underside show overhang that's made by a little high temperature..

As this part has an overhang close to the heat bed, it may be heated to much due to the extra radiation from the heat bed.

If you turn off the heat bed and using "blue tape" to print on, this might be much better.

Another way, reduce printing temp and increase the cooling fan flow may also help.

 

This is just general things, but if you attach your project file, -there is all the information needed for a closer look.

 

In here is lots of people that might have "your type of printer" having more insight around this "problem" using this printer.

 

Good Luck

 

Thanks

Torgeir

 

 

[leedav11 0]

Hi Thanks for replying, I' using the latest version of CURA - 4.12.1.

 

I think the issue with the bridge sagging is due to how the printer is printing the "bridge walls" green and red lines. I've done the temp and retraction calibration, i think the printer is printing the Overtrue PETG decently otherwise. print temp is 245degree

 

as you can see from the printed result, its the same 3 lines sagging in my printed part.

 

 

Also observed on the printed part the parts where the yellow line doesn't sag much at all - I think this is because these lines cross the bridge straight and starts on the inner most wall, so each bridge lines (yellow) is attached to 3 layers of wall and has a much better support and prevented the sagging.

 

 

Is it possible to override the setting in CURA to force walls layers (green and red) to print line bridge lines (yellow) on the very first layer of the bridge?

 

 

[leedav11 0]

i think i answered my on question regarding line thickness representation - i think its just means the printer is coasting

 

here is coasting at 100%

 

here is coasting at 0%

 

maybe because i print so fast i should not coast any at all so the layers won't sag.... I'll give this a shot..

 

But still is there a wall force all first layer bridge walls as simple bridge layers?

[Torgeir 243]

Right you are, it's coasting.

Did you ever try using:"Make overhang printable"?

Also "adaptive layers", may improve overhang problem much.

 

All in all, use Cura in analysis of the sliced project -before printing as it will save lots of time..

 

Torgeir