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Can You Use Weed Eater Line in a 3D Printer?

If you are anything like me, you’ve picked up a package of weed eater line and noticed that it is a dead ringer for a spool of filament. Its thin, plastic consistency feels like tough nylon filament, which begs the question: Can you print with it? 

You can use weed eater line in a 3D printer. The weed trimmer line usually consists of nylon, a standard 3D printing material. However, you may have some challenges with the line’s diameter, bed adhesion, warping, and moisture if you attempt to print with it. 

Using a weed eater line in a 3D printer is possible with the proper preparation and print settings – I’m living proof. However, you’ll need to know the peculiarities of printing with weed trimmer lines and how to best achieve good quality prints with it. So, let’s get into it and talk more about how you can make budget prints from your weedeater’s nylon line. 

Factors To Consider When 3D Printing With Weed Eater Line

Although you can print with a weed eater line, it isn’t as foolproof as printing with filament.

There are some peculiarities about the process, so keep reading to learn from my mistakes and discover how you can print with a weed eater line yourself. 

Weed Eater Line Diameters Can Vary

The first challenge of 3D printing with a weed eater line is the size or diameter of the plastic. Weed trimmer lines come in various sizes, but you will have to ensure that you get an appropriate size for your 3D printer’s extruder – which is easier said than done.

Weed eater lines’ sizes work on the standard sizes of weed whackers. However, these standard sizes are not consistent with most 3D printer extruder sizes, so you’ll probably have to get a slightly larger or smaller product than your typical filament. Also, most weed eater lines follow imperial measurements, which aren’t always easy (or accurate) to convert into millimeters. 

So, based on my experiments, here’s what you need to know about sizing your weed eater line for your 3D printer:

  • If you have a printer that requires 1.75 mm (0.07 in) filaments, you will want to choose a weed eater line close to 0.068 inches wide. The nearest size you will likely be able to find is 0.065 inches (1.65 mm) in diameter. 
  • If you have a printer that requires 2.85 or 3 mm (0.11 or 0.12 in) filaments, your weed eater line should be 0.11 inches (2.85 mm). You can find 0.11 inch (2.79 mm) weed eater string, but you can also make the more common ones with a diameter of 0.105 in (2.7 mm) work. 

Some Weed Eater Line Is Square, Ribbed, or Twisted

Some weed eater lines come in funky shapes with sharp edges or twisted ribbing to make whacking weeds easier. However, this texture doesn’t lend itself well to 3D printing, so it’s best to avoid these lines. I can’t say whether they will damage your printer or not, but I can promise that they will create extrusion inconsistencies and nozzle clogs. 

So, you will need to look for a smooth, round trimmer line that looks just like a genuine 3D printing filament for the highest chances of success.  

Weed Eater Line Is Likely Unsealed and Moist

Another problem you will run into is that the weed eater line is often damper than nylon filament

Nylon is a highly hygroscopic material, meaning that it will absorb moisture and humidity. When you attempt to print with a humid filament, the water turns into steam in your hot end, building pressure that results in extrusion issues, bubbling, stringing, and blobs. 

Nylon 3D printing filament manufacturers take moisture into consideration and keep their products sealed in airtight bags in a humidity-controlled environment. 

However, since most people use weed eater lines for lawn maintenance, this nylon string doesn’t undergo the same quality control measures that filaments do. Weed eater line is usually pretty damp out of the box, and the packaging is rarely airtight. So, you will need to dry it before printing. 

Still, there’s something strange about this “filament” and how it reacts to drying. Nylon is prone to delamination (bad layer adhesion), and leaving a bit of moisture in the filament can help prevent delamination. You should still dry the weed eater line before printing with it because it is likely very moist, but don’t let it go bone dry.  

I found the most success when I dried my weed eater line in my oven at 160 °F (71.1 °C) for five and a half hours, then stored the string in silica gel inside an airtight container between uses to maintain that dryness. 

Nylon Releases Toxic Gas

As a mandatory note for your safety, never print nylon indoors, especially non-filament-grade nylon such as weed eater line. 

In a recent study, researchers found that Nylon 3D printing filaments, both colored and uncolored, emitted 47 different toxic gasses and particles into the air during the printing process. Among these are notable poisons like formaldehyde and styrene. So, ventilation is critical when printing with anything nylon. 

Nylon Can Be Tricky to 3D Print With

Nylon warps and nylon weed eater lines do too. Due to this warping, it also suffers from delamination issues and bad bed adhesion, which you will need to remedy just like if you were working with a standard nylon filament. 

You will need to take special care to print this at a slightly higher temperature with shorter layers to ensure that your print does not warp or delaminate. In addition, using a bed adhesive like a glue stick or painter’s tape is mandatory when working with a weed eater line. Otherwise, your print will likely crack, warp, or topple over mid-print. 

For some more tips and advice, you may want to watch this brief video from someone else who tried the weed-whacker-filament experiment with quite a bit of success: 

Best Weed Eater Line for 3D Printing

For 1.75 mm Filament Printers: SuperTrim Round Trimmer Line

Works For: Ender 3, Prusa MK3S+ and Original, Anycubic Vyper, Dremel 3D20

This trimmer line is perfectly round, and my calipers set the diameter measurement right where it should be at 0.065 inches (1.65 mm).

It feels sturdier than many other weed eater lines of the same size, which ultimately helped my layers come out more smoothly with no stringing. It’s 100% nylon and only comes in blue. However, I find that the shade of blue looks precisely like most blue nylon filaments, so this one makes a great dupe. 

Overall, I saw the most success with this “filament,” and I highly recommend it if you want to try to print with a weedeater line. 

For 2.85 to 3 mm Filament Printers: Queenbox Round Weed Eater String

Works For: Most Ultimakers

This Queenbox Round Weed Eater string is advertised as a 0.11 inch (2.79 mm) line, but it actually comes in at around 0.1049 inches (2.66 mm). Despite this size inconsistency, it prints very well and has a smooth, solid texture for easy extrusion. 

It’s also 100% nylon, so you don’t have to worry about any oddities with the printing process or potentially harmful residues and additives. It only comes in a neon orange, which might be a pro or con depending on your aesthetics, but I quite like that it’s still the color of a weed eater line. 

Final Thoughts

You can 3D print with a weed eater line, and it makes a slightly challenging but fun project. You’ll need to find the right weed eater line with a size and shape that works with your 3D printer, and take care to dry it before printing. In addition, be sure to take all of the precautions that you would typically take when printing with nylon. 

With a bit of trial and error, you’ll be able to use a weed eater line as a substitute for nylon filament in no time.