3D Printer Filament Not Feeding: Why and How to Fix It?

This piece contains all you need to know about why the filament of a 3D printer isn't feeding and what can be done to rectify it.
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Last updatedLast updated: July 13, 2022
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If you are on this page, it means you’ve gotten started in 3D printing, and we don’t have to bore you about all the ways that 3D printing has developed and can be useful. Trusted Source The past, present and future of 3-D printing - The Washington Post Although the technology is being used mostly for prototypes, its use is likely to grow as the usability and economics make more sense. www.washingtonpost.com However, it also means that you’re having some printing problems in the form of 3D printer filaments not feeding.

Luckily, this is a solvable problem. Though there might be many reasons (and corresponding solutions) for a printer not feeding filaments, we will be covering all bases to help you get back to printing again.

In the spirit of offering endless value, we would also be providing tips on how to avoid this problem and some other similar ones.

Reasons Why Filament Doesn’t Feed

We have established that there is more than one reason for this problem, but all can be solved as well as prevented. Some of the issues are:

  • PTFE liner is worn out
  • Extrusion path clogging
  • Bad retraction settings
  • Weak extruder motor
  • Incorrect spring tension/idler pressure
  • Worn out extruder/feeder gears
  • Clogged nozzle

Each of these problems is touched on below:

PTFE Liner Worn out

3D Printer Filament Not Feeding: Why and How to Fix It?

There’s usually a PTFE tube lining the inside of the extruder.

Though this tube isn’t needed in all types of 3D printers, some Bowden-style printers (the Ender 3 model included) require this tubing to enhance the extrusion of their filaments.

Unfortunately, if this tubing is within the melting zone, it would soften and block the filament from being extruded. This is why it isn’t very uncommon to see ender 3 filaments not feeding. The problem is not permanent, though, and can be easily solved by replacing the PTFE tubing used in the lining with a new one. A smart choice recommended by experts and customers alike is the Authentic Capricorn PTFE Bowden Tubing.

Extrusion path clogging

For printing to go smoothly and as planned, the extrusion must be seamless and easy to control/pace. This is unlikely to be so if the extrusion path is blocked or clogged. Issues with the extrusion rate could completely damage the print even if it isn’t serious enough to stop the printing midway.

If you feel the faults with the feeding of the filament stems from here, you should check out the nozzle and the filament spool to be sure. The clogging may result from a too high or too low extrusion temperature. If there are no problems specifically wrong with the spool or nozzle, try changing the temperature after unclogging.

Bad retraction settings

The retraction settings of a 3D printer allow users to control the distance and rate of retraction of the filament into the extruder’s nozzle. This is particularly important when the extrusion location is changing as printing goes on. A bad setting to this critical printing element could come in one of two ways.

  • A slow setting would cause the filament to leak while the location is changing, leading to some sort of extrusion of material where there should be none.
  • A faster than appropriate setting would lead to the filament moving too fast within the spool, thus, grinding the filament and affecting its future movements.

Weak extruder motor

As the name implies, the extruder motor is in charge of pushing the filament into place for the extrusion of softened (melted) filament to take place. If the extruder motor is weak, it will affect the feed rate and the extrusion rate. Most times, this might start to manifest initially as a clicking sound made by the extruder motor. If you have to change the motor, a quality option like the STEPPERONLINE Nema 17 Stepper Motor is a great choice.

Incorrect spring tension/idler pressure

3D Printer Filament Not Feeding: Why and How to Fix It?

The spring tension within the 3D printer is often overlooked, but it is important to the aesthetic quality of your print.

Everyone knows how the tightness of the spring could affect the feeding of the filament, but very few people spend enough time perfecting the setting. You are going to need to get the hang of making this setting as perfect as possible if the goal is to 3D print homes Trusted Source The world's first 3D-printed neighborhood is being built in Mexico for families living on $3 a day - CNN A giant 3D printer built two houses in an impoverished, rural part of Mexico last week, breaking ground on what will be the first 3D-printed neighborhood in the world. amp.cnn.com , as has been reported by CNN.

Worn out extruder/feeder gears

There are also the drive gears to worry about. Like all mechanical parts of machines, they lose effectiveness over time, and worn-out gears are a common reason for the poor feeding of filaments. A change of drive gears and hot end are valid solutions to this problem.

Clogged nozzle

3D Printer Filament Not Feeding: Why and How to Fix It?

The clogs are usually caused by some melted filament sticking to the nozzle during extrusion.

Another reason (and one of the most common) for the poor feeding of filament in 3D printers is a clogged nozzle. This isn’t something that can be prevented from happening but regularly cleaning the nozzle would keep the detrimental effects of this at bay. There are other reasons why filament could be sticking to the nozzle as well, and they should be considered if other solutions are being mooted.

Solutions to unclog a nozzle

It should be noted that a clogged nozzle could be partially or fully clogged. The particular one plaguing the effectiveness of your printer would be dependent on the extensiveness of stuck filament in the nozzle.

The extent of clogging would consequently influence the method that is applied in unclogging the nozzle. The methods for unblocking the nozzle are explained below.

For unblocking a partially clogged nozzle

  • 3D Printer Filament Not Feeding: Why and How to Fix It?

    A brass brush helps you clean easily and does not damage the surface.

    Use a wire brush. The commonly used option is a brass wire brush

  • Use a cleaning filament. These types of filaments are used in cleaning the nozzle. To use them, print with the filament following the settings recommended by the manufacturer and, while they print, they carry along whatever leftover filaments are in the nozzle. They are also used when filaments are to be changed as they would prevent filaments of different physical characteristics from coming together and messing up the integrity of a print.
  • Manual pushing. This is carried out by heating the nozzle to printing temperature then manually forcing out the leftover filaments within. It is expected that they would be softer and easier to dislodge the warmer they get.

For unblocking a fully clogged nozzle

  • 3D Printer Filament Not Feeding: Why and How to Fix It?

    A guitar string or acupuncture needle is used to dislodge the source of the blockage.

    Use a guitar string or needle. The needle and string have a smaller diameter than the nozzle and are less likely to damage it. Similar to the manual pushing method for unblocking partially clogged nozzles, the nozzle is to be heated first before the needle or string is used. Subsequent extrusions should see the blocking particles released along with the extruded filaments.

  • The atomic/cold pull. This method involves heating the nozzle while using nylon or ABS material (the fragility of PLA makes it unsuitable). The nozzle should be heated (to 250℃) for about 5 minutes until the filament starts to dribble down the nozzle. Then it should be left to cool to room temperature before heating back up to 120℃. After the second heating cycle, the filament material is pulled out firmly with the blocking particles within it. The process could be repeated many times until the cold filament that is pulled out has no particles in it and has its tip in the shape of the nozzle.
  • Use of acetone. This involves using acetone as a solvent for the obstructing plastic particles. Trusted Source Effects of Acetone on Plastic | Education - Seattle PI Effects of Acetone on Plastic. Acetone, also called dimethylketone or propanone, chemical formula (CH₃)₂C=O, is a commonly used, relatively inexpensive solvent. education.seattlepi.com Here, the nozzle is removed and placed completely in acetone for 24 hours, with occasional shaking or the use of a needle on the inside. After 24 hours, the nozzle should be removed and thoroughly dried to eliminate any chemical traces.
  • Use of a blowtorch or heat gun. A blowtorch shouldn’t be used directly as it can melt the nozzle, but a heat gun can be used directly. To facilitate this approach, remove the nozzle from the printer and hold it in a fixed position with pliers before applying the heat gun. After a few minutes, allow the nozzle to cool and check for any obstruction. The process could be repeated until it’s no longer necessary.

How to fix filament feeding

3D Printer Filament Not Feeding: Why and How to Fix It?

It is crucial to test it after fixing it.

We have explained how to go about solving the problem of a clogged nozzle and have even given some solutions to the other potential problems but before resorting to those, here are quick and specific ways to go about fixing the filament feeding in your printer:

  1. Monitor and adjust the hot end temperature.
  2. Check the amperage of the extruder motor to determine if the problem has anything to do with the power supply and input
  3. Check to ensure that the filament between the pulley and gear isn’t too tight, as this could affect the flow
  4. Removing the extruder, disassembling it, and cleaning it. This isn’t simple or quick, but sometimes all you need is some deep maintenance work to get your printer working well again. Some oiling can come in handy as well.
  5. Try changing the filament material that is used but be careful because doing it the right way is very important

How to fix Ender 3 filament feeding

You might find yourself in a unique situation where many of the solutions we have offered would not work out for you. One problem that could have occurred if your printer is an Ender 3 would be that of a loose extruder cog. Simply lining the cog up with the feeder disc and retightening it would solve the problem.

Reasons why filament doesn’t pull from the extruder

Not flowing plastic

3D Printer Filament Not Feeding: Why and How to Fix It?

It might be because of the liquid plastic that got hardened in the cold side of the hot end and the nozzle got jammed.

As we have stated earlier, leftover filaments may harden in the nozzle during extrusion and printing and gradually build up a significant obstruction. This type of obstruction could slow down the plastic flow and facilitate the buildup of an even bigger clog. This can be solved by regular cleaning and maintenance of the extruder and nozzle.

Not primed extruder

Before printing, the extruder has to be primed. This might even be more critical if a different plastic material was used in the previous cycle. Printing plastics have different characteristics (for instance, PETG differs from ABS) and priming (and) ensures that the factors from a previous cycle do not affect the current one.

Heat Creep

3D Printer Filament Not Feeding: Why and How to Fix It?

It will make your filament viscous, and you would run into this heat creep issue.

This is a problem that originates from the hot end, filament, and poor heat settings. As the name implies, the heat creeps us and raises the temperature of the hot end prematurely, causing the filament to melt early as well.

The problem could develop during or after printing and manifest in a finished print as a fuzzy top. The issue of heat creep comes up in hot ends without a PTFE liner. Hence, the PTFE liner mentioned earlier (which can influence poor filament feeding when of low quality) is not simply a design prop. Thankfully though, the heat creep is solved by:

  • Lowering the temperature of the hot end
  • Increasing the printing speed
  • Increasing the fan speed for rapid cooling effects
  • Simply changing the entire hot end

Final thoughts

3D printing is interesting enough without the developments it always seems to be undergoing. However, it would be difficult to enjoy if you keep on stumbling from problem to problem, and we are here to help you solve the problems and maintain your momentum.

That aside, though, you shouldn’t feel too badly about stumbling onto this issue as it is one that only experience can guide against. The problem of a 3D printer filament not feeding is that popular, and we hope to have helped solve yours.

Regardless of whether you solve this problem on your own, don’t give in to these growing pains and keep printing! If we haven’t, it might be time for you to call an expert. Besides repair, another benefit of inviting an expert is that you get to learn more and ask the questions that might have been bugging you.

References

1.
The past, present and future of 3-D printing - The Washington Post
Although the technology is being used mostly for prototypes, its use is likely to grow as the usability and economics make more sense.
2.
The world's first 3D-printed neighborhood is being built in Mexico for families living on $3 a day - CNN
A giant 3D printer built two houses in an impoverished, rural part of Mexico last week, breaking ground on what will be the first 3D-printed neighborhood in the world.
3.
Effects of Acetone on Plastic | Education - Seattle PI
Effects of Acetone on Plastic. Acetone, also called dimethylketone or propanone, chemical formula (CH₃)₂C=O, is a commonly used, relatively inexpensive solvent.
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