Bridging is a term in 3D printing that refers to a horizontal extrusion of material between two raised points, but they aren’t always as horizontal as we want them to be.
I’ve gone through experiences where my bridging was quite poor, so I had to search for a fix. After doing some research, I decided to put together this article to help other people solve this issue.
The best way to fix poor bridging is to improve your cooling system with a better fan or cooling duct. Next, you can decrease your printing speed and printing temperature to allow your extruded filament to cool faster while in the air. Over-extrusion is an enemy when it comes to bridging, so you can decrease flow rates to compensate.
This is the basic answer to fix poor bridging, but keep on reading for some detailed explanations on how to fix this issue once and for all.
Why Am I Getting Poor Bridging in My 3D Prints?
Poor bridging is a very common problem that usually occurs when a user tries to print a part of the object where there is no support below that part.
This is referred to as bridging because it mostly occurs while printing a short object where the user doesn’t add any support to save time as well as the printing material.
This phenomenon can sometimes cause a problem of poor bridging when some threads of the filament tend to overhang from the actual part horizontally.
It can often occur but the best part is that the problem can be eliminated easily just with the help of some techniques.
Finding the cause of the problem will make the process easy for you and will allow you to fix that only part which is causing the problem instead of testing each part of the 3D printer.
- The Cooling is Not Enough for the Filament to Solidify
- Printing at High Flow Rate
- Printing Speed is too much High
- Using a Very High Temperature
- Printing Long Bridges without any Support
How to Fix Poor Bridging in 3D Prints?
While printing an object the main aim of the user is to get a print the same as it is designed. A minor problem in printing can produce disappointing results which can waste time and effort, especially if it is a functional print.
Finding the reason and fixing the problem is necessary because it may not ruin your complete project but it will definitely affect the look and the clarity of your prints.
If you notice any dropping or sagging of the filament, pause the printing process, and try to fix this problem at the beginning because the time you will take will affect your print.
Let’s talk about some of the most effective and highly recommended solutions and techniques that will help you to not only fix the poor bridging problem but will also prevent other problems.
1. Increase Cooling or Fan Speed
The easiest and simplest solution to avoid poor bridging is to increase the fan speed to provide enough cooling to your prints to get solid.
The filament will tend to drop or the melted threads will overhang if it does not become solid immediately and cooling is necessary to get the job done.
- Make sure that the cooling fan is doing its work properly.
- After the first few layers, set the cooling fan speed to its maximum range and notice the positive effects on your bridging
- Get a better cooling fan or cooling fan duct to direct cool air to your 3D prints
- Keep an eye on the print because it is possible that too much cooling can cause other problems such as clogging.
- If something like this happens, decrease the fan speed step by step and stop where you notice that everything is working efficiently.
2. Decrease Flow Rate
If too much filament is extruding from the nozzle, the probability of the poor bridging problem will increase to many folds.
When the filament will extrude in a huge amount this will require comparatively more time to become solid and stick to the previous layers properly.
High flow rates can not only become a reason for poor bridging but will also make your print look quite low quality and dimensionally inaccurate.
- Decrease the filament flow rate step by step, this will help the layers to cool down quickly.
- You can even use a flow rate tower to calibrate the optimal values
- Make sure that the flow rate is properly set because too slow flow can cause under extrusion, which is another problem itself.
3. Decrease Print Speed
Printing at high speed is the cause behind most of the problems that occur in 3D printers and poor bridging is one of them.
If you are printing at a high speed the nozzle will move quickly and the filament will not have enough time to get stuck to the previous layer and become solid.
- If you think that high speed is the actual reason try decreasing the print speed step by step and see if any improvements occur.
- You can also print yourself a speed tower to calibrate speed and its performance with bridging.
- It is also recommended to not slow down the print speed too much because it will cause the filament to suspend in the air resulting in the bending or hangings of the strands limply.
4. Decrease Print Temperature
Just like the print speed and filament flow rate, the temperature is also a major factor in completing a 3D printing project of good quality.
Just remember that in these types of scenarios printing at a bit low temperature usually works and solves the problem completely.
The best suitable temperature for bridging depends on the type of filament material you are using.
- According to the experts the perfect temperature for the most common types of filaments such as PLA fall somewhere between 180-220°C.
- Make sure that the print temperature doesn’t go too low because it can result in other failures such as under extrusion or poor melting of the filament.
- Try lowering down the temperature of the print bed if the bridging layers are being printed near to the bed.
- It will prevent layers from the consistent heat coming from the bed because it will not allow the filament to solidify.
5. Add Supports in your Print:
Adding support to your print structure is the most efficient solution to the problem. If you are printing long bridges then using supports is essential.
Adding support will decrease the distance between to open points and this will reduce the chances of poor bridging.
You should try this solution if you cannot get your expected results by implementing the above-mentioned suggestions.
- Add supporting pillars or layers to provide an extra foundation that will help your print to avoid poor bridging.
- Adding support will also provide a clear look with a resultant object of high quality.
- If you don’t want supports in your structure, you can also eliminate them or cut them off after the print is completed.
- Add supports in a manner that these can be eliminated from the print easily because if they adhere to the print strongly, getting rid of them will become too difficult.
- You can add custom supports using certain software