How to Avoid String in Your 3D Prints: 3 Crucial Settings
Credit: @Montgomery Haverton
Great Thanks to you and your share
Like anything else in life, 3D printing is a learning process that will never end. Every time I think that I have mastered a certain aspect of this, the machine proves me wrong. That being said, I do believe now that with a lot of patience and a lot of input from others, I have finally figured out how to keep my prints from looking like they are covered in spider webs. Those annoying and extremely thin strings that were present on my prints added a lot of time on my finishing touches and more times than not, left tiny dots all over my prints that needed to be removed with a knife or Dremel.
The first and most important step to eliminating these is experimenting. Because every filament and every print does not have a “one size fits all” setting, you are going to have to tweak your settings, and tweak again, and tweak again, and even when you find the right setting, you will have to continue the tweaking. I’m going to give you a few tips on the most influential settings that can fix those annoying lines to get you started though.
Nozzle temperature is probably the most important setting to get right. If you are too low, your filament is not going to come out of the nozzle at the correct speed, and you will cause a backup in the extruder. You will know that your temperature is too low if you can see or hear the feeding wheel start skipping and clicking. If your temperature is too high, the spider web lines will be present because you will have minor overflow when the nozzle retracts. That minor overflow stays constant and it travels with the extruder to the next point. You need to get the temperature to a consistent point where the filament flows nicely when the nozzle is on the print but stops flowing when the nozzle RETRACTS from the print. Imagine that you are pouring syrup on a pancake. If the syrup is cold, it stays together when you are done pouring, and it retracts back into the bottle. If you heat up the syrup, it changes the consistency, so when you are done pouring, there is always that string that hangs onto the pancake and leaves a line from the pancake, along the table, and back to the bottle. You aren’t going to get this temperature correct right away, but if you keep a log of the filaments and temperatures that you used followed by the results that they yield, you will see a pattern.
Print Speed and Infill Speed
Print speed and infill speed each coincide with one another in a major way, and they are dependent on the temperature, nozzle size, and type of bed that you are printing on. If you have your print speed set too high, the filament will not have the chance to retract back into the nozzle before it moves to another spot in the print. Even if there is a fraction of a millimeter hanging out of the nozzle when it retracts, it has the potential to cause lines to form within your print…especially if your temperature is too high.
Retraction Distance Setting
Lastly is the retraction distance setting. This needs to be set in a manner that allows for enough separation between the nozzle and the print during any moment of transition for one piece to another. If the retraction distance is too high, the nozzle will raise entirely too high and it will interrupt the flow of the print. If it is too low, you are not giving the nozzle enough time to break the connection with the portion of the print that it just finished and this results in….. you guessed it, LINES that cross with the nozzle.
So, these are the three settings that I have focused on the most since I have begun printing. I have played with them a lot and seen differences with every change. If you are stuck, reach out to the ANET support groups and get some advice from people who have been doing this for a while. Everyone will be eager to help you because they went through these problematic situations as well. As I said earlier, keeping a log of your adjustments is the greatest tool that you can have, so do yourself a favor and get that going. In closing, these are just the opinions of myself and the people who have helped me in achieving some pretty good prints. Just remember, if you aren’t having fun with this hobby, you definitely aren’t doing it right.