- One 3D printing expert we consulted recommends some general fixes
- Utilize a tiny bit more retraction
- Make sure the filament is dry
- Slightly lower the temperature
- Some filament really just has to flow stringy to get the rest perfect.
- Invest in a heat gun which will help shrivel the strings so you can rub them off with your hand or by using a hobby knife.
3D stringing happens when your 3D printer leaves a trail of stringy or gooey filament between printed layers, resulting in an undesirable finish on the surface of your print. This is due to a phenomenon known as oozing.
The filament used by 3D printers is made up of long, thin strands of plastic. When the hot end nozzle moves to a new point in space for each layer during a print, it lays down a single bead of this material on the print bed.
This keeps the path of the extruder nice and stable, allowing very precise control of the print head. But this also means that when it’s time to begin a new layer, there is filament already laid down on the surface which can be dragged along with the nozzle as it moves into position for printing.
This causes strands and blobs of plastic to form as filament oozes out and cools between printed layers.
3D print stringing causes excess material to come out of the nozzle in long strings. This is because it doesn’t have much resistance when it oozes out, so there’s very little force keeping the filament in place.
It also doesn’t have time to cool properly before being squished by the extruder head again, resulting in a stringy mess.
3D Print Stringing most often happens on the lower layers because it is already starting to cool by the time the head moves up to print the next layer. Thus there is less ooze-resistance and stringing.
3D Print Stringing can also happen when printing small features or thin walls. You may notice that your printer will sometimes print rows of dots if it’s trying to create a line. If the head moves too fast or there are not enough points in contact with the bed, you may get this same effect.
This is typically more common on printers with smaller nozzles (0.3mm and under).
5 Ways to Reduce & Prevent 3D Print Stringing
There are several ways you can minimize or prevent 3D print stringing, but these are the five best ways :
1. Adjust your fan speed settings
One of the easiest ways to reduce stringing is adjusting your fan speed, which is sometimes referred to as cooling power. Generally speaking, the higher the fan speed for printing PLA (and ABS), you less likely it is to have stringing.
Lower fan speeds can be used when you want to minimize overall print time, but there is a downside to trying to save it: You may get messy and ugly prints, or more likely, incomplete prints. To adjust your fan speed settings:
- Press the ‘Home’ key on your keyboard (it’s usually the key with a little house on it).
- Press the ‘+’ or ‘-‘ keys until you see Fan0 displayed on your screen.
- Use the arrow keys to change the percentage of fan speed that will be used during your print. 0% is off, and 100% is full power, so 50% is half power.
- Press the ‘M’ key to save your settings.
2. Try a Cold Pull or Retraction Move
If retraction does not prevent enough excess material from oozing out, it is time to try a cold pull or retraction move instead. This type of retraction happens before the nozzle moves to a new location, instead of after like the regular Retract move.
To do this, reduce your retraction distance or length by about 1mm (try 0.9mm first). If you’re using Cura for 3D printing, go into Expert Mode (by clicking on the button that looks like a screwdriver and wrench) and click on ‘Edit Process Settings.’
This will bring up the process settings window where you can change your Retraction Distance or Retraction Length depending on whether you are extruding or not.
3. Get a Nozzle with a Smaller Opening
If you’re using an FFF 3D printer, another option to try is to get a nozzle with a smaller opening. The smaller the opening, the less likely stringing is an issue because it has less area for excess material to escape through.
For example, if your extruder is 0.4mm in diameter, you could either try printing with a 0.2mm nozzle or use a drill bit to widen the existing opening.
4. Keep your Fans On
If you want to be sure that you will not have any problems with stringing, then try this: Start a print, and as it is running, turn the cooling fan speed up as high as possible. You can do this by simply pressing the ‘+’ key on your keyboard until the fan is as loud as possible.
But keep in mind that this will probably slow down your print and may even cause other problems such as poor surface quality.
5. Increase Your Print Speed
Well, if you still have a problem with Stringing after trying the other options, then increase your print speed by 5% or 10%. This is not always an ideal solution since it may lead to other issues such as poor surface quality and blobs. But in some cases, increasing your print speed just a tiny bit will make the difference between stringing and no Stringing.
Stringing is not always a bad thing. If you are printing something that needs support material, then the stringing can be very helpful because it provides build-in support material, which saves you time to clean up.
But if it’s not something that needs support material, then you want to do everything in your power to prevent Stringing.
Besides those five tips, you could do a combination of them by adjusting your fan speed settings first and then if Stringing still occurs even after increasing print speed, try a Cold Pull or Retraction Move.
Hopefully, these five easy ways to prevent 3D print Stringing will help you achieve the results you’re looking for.