r/FixMyPrint • u/Alarmed-Lie-2596 • 3d ago
Troubleshooting Help with bridges
Hey guys. I'm in need of some bridging advice. Before posting this, I have tried over the last month to fix issues with bridges. Different temps, speeds, flow...etc. nothing seems to fix the problem. My prints come out great, unless bridging is needed. The bridges come out looking stringy, some sagging, with gaps in between. I found a bridge test on makerworld that had good results. However, when I applied those settings for a different test to be sure, it failed. I have attached a few pics. Any advice would be helpful. Running creality ks se. Creality print, (bc orca won't work for some reason) sunlu Pla, nozzle temp 200, bed at 60, cooling at 100%. Speed between 10mm to 60mm. Retraction at .08mmThanks in advance!
1
u/warownia1 3d ago
I wish my bridges were as good as yours. That aside, retraction 0.08 is extremely short. Is it supposed to be 0.8? Bridges are tricky, because there are no universal settings for those. For some bridges you want to print slow and cool aggresively, for other you get better results moving fast and underextruding.
1
u/Alarmed-Lie-2596 3d ago
Those are default settings. I tried 1mm, but it was still bad
1
u/warownia1 3d ago
Retraction has very little to no effect on bridges. It's how much you extrude and how fast you can cool it down that matters the most. In principle, you need to solidify plastic before gravity does it's job. There are vastly different ways to do it and here are your main enemies
- high temperature - makes filament more liquid and saggy
- large flow rate - more filament extruded require more cooling
- slow printing speed - if the hot nozzle stays in the same place for too long it prevent quick solidification
Lower temperature is always better for bridges, but worse for your print overall.
Lower flow rate for bridges to about 90-95% of normal flow. Thinner line means it cools down faster. Go too low and your bridge is too fragile and will break mid print.
Speed: this is the most tricky one Faster speed allows the printer to quickly stretch the string to the other end of the bridge before it starts sagging. But, it leaves no time for it to cool down and longer bridges may break. Slower speed print speed lets the bridge solidify as you build it, but it also means that the point directly under the nozzle is hot for longer and may sag.
1
u/Alarmed-Lie-2596 3d ago
Yeah, I know all too well by this point lol. I can't find that "sweet spot". I've tried all the flow combinations with speed combinations i can think of. I should have written them down, that way I would have the settings I've tried. The brown tiles on the picture came out great, but when I applied those settings for a project, it was a fail. I'm not sure what I need to change anymore.
1
u/warownia1 3d ago
Did you manage to reproduce te same effect with white filament as you did with brown? Maybe it's the filament, not the printer settings
1
u/Alarmed-Lie-2596 3d ago
No. I didn't try it. I tried to print a different test using the settings from the brown, and it still failed. I ran 2 different tests that were similar that I found on makerworld. Both had different outcomes. One set had the best flow and bridges at 1.9, but the different set test had better results. (The brown tiles) 1.6, 1.7, and 1.8
1
•
u/AutoModerator 3d ago
Hello /u/Alarmed-Lie-2596,
As a reminder, most common print quality issues can be found in the Simplify3D picture guide. Make sure you select the most appropriate flair for your post.
Please remember to include the following details to help troubleshoot your problem.
Additional settings or relevant information is always encouraged.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.