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Why your 3D Prints Look Ugly (Quick Fix)

Struggling with stringy, sagging bridges? Master cooling, flow ratio, bridge speed, and fake bridges to get clean overhangs without supports.

Tutorials 2:29 27 views Jul 09, 2026
#3d printing bridges #bridge settings #3d print quality #bridge flow ratio #bridge speed #part cooling fan #fake bridges #slicer settings #3d print calibration #supportless 3d printing

About this video

Video by Vitek Innovation: Instagram Profile

Why Your 3D Prints Look Ugly: The Bridge Problem

If your 3D prints look stringy, saggy, or messy between two upright surfaces, the culprit is almost always your bridge settings. Bridging happens when your 3D printer extrudes filament across an empty gap between two already-printed points. Getting this right eliminates the need for wasteful support structures and dramatically improves overall 3D print quality.

The Custom Bridge Test Model

Before tweaking slicer settings blindly, print a simple bridge test model. A calibration model lets you compare settings side-by-side on your specific printer, since results vary between machines, nozzles, and filament brands. Start with the recommended values below, then fine-tune from there.

Key Bridge Settings to Adjust

  • Cooling (Part Cooling Fan): Set to 100% during bridging. Maximum airflow helps filament solidify instantly, keeping the line taut instead of drooping.
  • Printing Temperature: Drop your normal print temperature by 5–10°C during bridges. Cooler filament is stiffer and less prone to sag.
  • Bridge Flow Ratio: Controls how much plastic is extruded.
  • Long bridges (30mm+): Increase flow to around 1.5 — extra material gives the nozzle something to "catch" on across the gap.
  • Short bridges (under 30mm): Lower flow to 0.7–0.8 to avoid blobs and over-extrusion.
  • Bridge Speed: Slow it down. Around 10 mm/s gave the best results in testing, giving the filament more time to cool mid-air.
  • Fake Bridges: A newer slicer feature for gaps above 70mm. It treats the span as multiple short bridges, drastically improving success on long overhangs. Enable it if your slicer supports it.

Step-by-Step Workflow

  1. Download or design a simple bridge test model.
  2. Apply the baseline settings (cooling 100%, temp −5 to −10°C, flow 1.5 for long / 0.8 for short, speed 10 mm/s).
  3. Print and inspect the underside of each bridge for sagging, stringing, or gaps.
  4. Adjust flow and speed in small increments until bridges are clean and flat.

Frequently Asked Questions

What is a bridge in 3D printing?
A bridge is a horizontal span of filament extruded between two printed points with no support directly beneath it.

What is a good bridge flow ratio?
For long bridges, 1.5 works well; for short bridges, drop it to 0.7–0.8.

How fast should bridges print?
Slower is better. 10 mm/s is a reliable starting point for clean bridges.

Do I need supports for bridges?
With optimized bridge settings, you can often eliminate supports entirely, saving filament and print time.

Full Transcript

Intro & The Stringy Bridge Problem if your 3D prints look like this you probably have your bridge settings wrong and in this video I would love to help you out figure out your best bridge settings so that you can have the perfect print quality and even eliminate supports that would have to be under the bridges if you didn't have the bridge settings correctly and who would like to waste filament and time on supports if you can just perfect your bridge settings and then don't need the supports at all The Custom Bridge Test Model I designed this very simple bridge test model so that we can actually calibrate it on your own printer because the settings may depend of course I will show you my best settings because I think they are a great starting point for everybody the first important thing is to understand that bridging is basically the printer going between two things that are already printed and making a line over them and so what we want to happen is for the filament to cool down as fast as possible Setting 1: Cooling & Temperature for this reason the first setting that we need to concentrate on is the cooling for the best bridges I would recommend putting the cooling to 100% and to make the line as rigid as possible between these two objects it can actually help the temperature even by printing it at a lower temperature from the start I recommend lowering down the printing temperature somewhere between 5 to 10 degrees below the normal printing temperature the next most important part is the bridge flow ratio Setting 2: Bridge Flow Ratio (Short vs. Long) which is very often overlooked because what that says is how much filament will be extruded from the nozzle so if you set the bridgeful ratio higher there will be more filament and if lower there will be less but if you are making the longer bridges the higher the flow ratio the more filament there will be for the printer to catch on while it's travelling the long distance so for longer bridges I would recommend increasing it to 1.5 but for the shorter ones I would recommend decreasing it somewhere around 0.8 to 0.7 and for shorter bridges I mean something below 30 millimeters around there and since we are already extruding more filament Setting 3: Bridge Speed how fast will we extrude it is also important and for this I found that lowering down the speed of the bridges actually helps the cooling down so it even makes better bridges and the best result that I got were with 10 millimeters per second and if you are printing actually very long bridges Setting 4: "Fake Bridges" for Long Gaps there's a new feature that you can turn on which is called fake bridges which is only for very long distances something above 70 millimeters which not all slicers have but if you have it and you are printing a longer bridge definitely turn it on now try to apply these settings with the model Test, Adjust, and Perfect! with your filament and with your 3D printer and see what it does and after you see it you should be able to move from there and adjust it for your own need and just like this you should be able to get a lot better bridges and I hope this improves your prints