Help UM2: First layer of bridging is very weak

[oskars 0]

Hi!

I am trying to print a drag chain (I have attached the STL) and it has this 22mm bridge which I get a lot of trouble with.

 

As you can see on these pictures the first one or two layer when the bridging starts are really weak. They are so weak that they easily pops of with some minor pressure on them.

 

Printer: Ultimaker 2 (35W heat cartridge, custom fan shroud)

Material: BASF Ultrafuse PET
Temperature: 220 C

Print speed: 60mm/s

Experimental bridging enabled

Cura 4.12.1

 

I have tried different print speeds, different temperatures but I can not solve this. It seems like the experimental bridge settings are screwing this up for my printer, because I don't get the same effect when NOT using the bridge settings. I think I need the experimental bridge settings because the gap is much harder for my printer to print nicely if I don't use it.

 

I hope someone can understand my problem. I think the images explains it better then my text 😄

 

/ Oskar

 

DC_2mm_1_link.stl

Edited December 22, 2021 by oskars

[oskars 0]

I have done some more testing and I have concluded that turning off "Bridge has multiple layers" doesn't help.

 

The problem seems to be in this part:

 

 

It feels like it is the first "WALL-OUTER" in this layer that is printed poorly due to maybe decreased flow rate?! But it doesn't seem to be decreased. I use F1800 for all other "normal" outer walls also.

 

;LAYER:49
;TYPE:WALL-OUTER
;MESH:DC_2mm_1_link.stl
G1 F1800 X96.4 Y124.688 E1475.27356
G1 X96.4 Y109.218 E1476.51116
G1 X98.6 Y109.218 E1476.68716
G1 X98.6 Y109.093 E1476.69716
G1 X98.6 Y107.218
G1 X100 Y107.218
;TYPE:WALL-OUTER
;BRIDGE
G1 F900 X123 Y107.218 E1477.61716
;TYPE:WALL-OUTER
G1 X124 Y107.218 E1477.77716
G1 F1125 X124.4 Y107.218 E1477.82836
G1 F1800 X124.4 Y109.218 E1477.98836
G1 X126.6 Y109.218 E1478.16436
G1 X126.6 Y124.688 E1479.40196
G1 X125.15 Y124.688 E1479.51796
G1 X125.15 Y122.293 E1479.70956
G1 X125.15 Y120.418
G1 X125.15 Y120.018
;TYPE:WALL-OUTER
;BRIDGE
G1 F900 X97.85 Y120.018 E1480.80156
;TYPE:WALL-OUTER
G1 F1800 X97.85 Y124.688 E1481.17516
G0 F7200 X97.65 Y124.688
G0 X97.38 Y124.218
G0 X97.38 Y119.548
G0 X97.45 Y119.618
;TYPE:WALL-INNER
G1 F3600 X97.45 Y124.288 E1481.54876
G1 X96.8 Y124.288 E1481.60076
G1 X96.8 Y109.618 E1482.77436
G1 X99 Y109.618 E1482.95036
G1 X99 Y107.618
G1 X100 Y107.618
;TYPE:WALL-INNER
;BRIDGE
G1 F900 X123 Y107.618 E1483.87036
;TYPE:WALL-INNER
G1 F1800 X124 Y107.618 E1484.03036
G1 F3600 X124 Y109.618 E1484.19036
G1 X126.2 Y109.618 E1484.36636
G1 X126.2 Y124.288 E1485.53996
G1 X125.55 Y124.288 E1485.59196
G1 X125.55 Y121.805 E1485.7906
G1 X125.55 Y119.618
G1 X125.15 Y119.618
;TYPE:WALL-INNER
;BRIDGE
G1 F900 X97.85 Y119.618 E1486.8826
;TYPE:WALL-INNER
G1 F1800 X97.45 Y119.618 E1486.9466
G0 F7200 X97.38 Y119.548
G0 X125.238 Y118.656
G0 X125.238 Y113.99
G0 X123.6 Y110.018
G1 F3600 X125.8 Y110.018 E1487.1226
G1 X125.8 Y117.031 E1487.68364
G1 X125.8 Y119.218
G1 X125.15 Y119.218
;TYPE:WALL-INNER
;BRIDGE
G1 F900 X97.85 Y119.218 E1488.77564
;TYPE:WALL-INNER
G1 F1800 X97.2 Y119.218 E1488.87964
G1 F3600 X97.2 Y110.018 E1489.61564
G1 X99.4 Y110.018 E1489.79164
G1 X99.4 Y108.018
G1 X100 Y108.018
;TYPE:WALL-INNER
;BRIDGE
G1 F900 X123 Y108.018 E1490.71164
;TYPE:WALL-INNER
G1 F1800 X123.6 Y108.018 E1490.80764
G1 F3600 X123.6 Y110.018 E1490.96764
G0 F7200 X123.21 Y110.408
;TYPE:SKIN
G1 F1800 X125.41 Y110.408 E1491.14364
G1 X125.41 Y117.078 E1491.67724
G1 X125.41 Y118.828
G1 X125.15 Y118.828
;TYPE:SKIN
;BRIDGE
G1 F900 X97.85 Y118.828 E1492.98764
;TYPE:SKIN
G1 X97.59 Y118.828 E1493.02924
G1 F1800 X97.59 Y110.408 E1493.70284
G1 X99.79 Y110.408 E1493.87884
G1 X99.79 Y110.158 E1493.89884
G1 X99.79 Y108.408
G1 X100 Y108.408
;TYPE:SKIN
;BRIDGE
G1 F900 X123 Y108.408 E1495.00284
;TYPE:SKIN
G1 X123.21 Y108.408 E1495.03644
G1 F1800 X123.21 Y110.408 E1495.19644
G0 F7200 X125.238 Y113.99
G0 X125.409 Y118.8
;TYPE:SKIN
;BRIDGE
G1 F900 X97.589 Y118.8 E1496.5318
G0 F7200 X97.589 Y118.4
G1 F900 X125.409 Y118.4 E1497.86716
G0 F7200 X125.409 Y118
G1 F900 X97.589 Y118 E1499.20252
G0 F7200 X97.589 Y117.6
G1 F900 X125.409 Y117.6 E1500.53788
G0 F7200 X125.409 Y117.2
G1 F900 X97.589 Y117.2 E1501.87324
G0 F7200 X97.589 Y116.8
G1 F900 X125.409 Y116.8 E1503.2086
G0 F7200 X125.409 Y116.4
G1 F900 X97.589 Y116.4 E1504.54396
G0 F7200 X97.589 Y116
G1 F900 X125.409 Y116 E1505.87932
G0 F7200 X125.409 Y115.6
G1 F900 X97.589 Y115.6 E1507.21468
G0 F7200 X97.589 Y115.2
G1 F900 X125.409 Y115.2 E1508.55004
G0 F7200 X125.409 Y114.8
G1 F900 X97.589 Y114.8 E1509.8854
G0 F7200 X97.589 Y114.4
G1 F900 X125.409 Y114.4 E1511.22076
G0 F7200 X125.409 Y114
G1 F900 X97.589 Y114 E1512.55612
G0 F7200 X97.589 Y113.6
G1 F900 X125.409 Y113.6 E1513.89148
G0 F7200 X125.409 Y113.2
G1 F900 X97.589 Y113.2 E1515.22684
G0 F7200 X97.589 Y112.8
G1 F900 X125.409 Y112.8 E1516.5622
G0 F7200 X125.409 Y112.4
G1 F900 X97.589 Y112.4 E1517.89756
G0 F7200 X97.589 Y112
G1 F900 X125.409 Y112 E1519.23292
G0 F7200 X125.409 Y111.6
G1 F900 X97.589 Y111.6 E1520.56828
G0 F7200 X97.589 Y111.2
G1 F900 X125.409 Y111.2 E1521.90364
G0 F7200 X125.409 Y110.8
G1 F900 X97.589 Y110.8 E1523.239
G1 X97.489 Y110.8
G0 F7200 X99.789 Y110.4
G1 F900 X123.209 Y110.4 E1524.36316
G0 F7200 X123.209 Y110
G1 F900 X99.789 Y110 E1525.48732
G0 F7200 X99.789 Y109.6
G1 F900 X123.209 Y109.6 E1526.61148
G0 F7200 X123.209 Y109.2
G1 F900 X99.789 Y109.2 E1527.73564
G0 F7200 X99.789 Y108.8
G1 F900 X123.209 Y108.8 E1528.8598
G1 X123.309 Y108.8
G0 F7200 X125.238 Y113.99
G0 X125.826 Y119.397
G0 X125.785 Y119.438
;TYPE:SKIN
G1 F1800 X125.873 Y119.632 E1528.87091
G1 X125.873 Y123.875 E1529.09219
G1 X125.971 Y124.06 E1529.1031
G0 F7200 X126.003 Y124.029
G0 X125.578 Y119.59
G0 X97.422 Y119.59
G0 X97.254 Y123.928
G0 X97.172 Y124.01
G1 F1800 X97.124 Y123.775 E1529.11608
G1 X97.124 Y119.532 E1529.34558
G0 F7200 X97.2 Y119.336
;MESH:NONMESH
G0 F600 X97.2 Y119.336 Z10.3
G0 F7200 X97.85 Y120.018
;TIME_ELAPSED:770.224606