Extruder clogged at mid-print? Learn how to save it!
Unfortunately this issue happens more than we could expect, especially with a low quality extruder / filament and also on some special filaments as wood and metallic. So we will approach from two fronts, how to prevent it to happen, and how to save a print if it happens.
How to prevent clogging in 3d printers!
The first tip is, and believe, it is a must-have! its a filament dust filter. its pretty simple and you will only need a bit of filament to print, a small sponge and a bit of oil (optional but recommended)
After you print this filter, cut a small block of sponge (a new kitchen sponge is great for it), and put it inside the filter. you can also use the filter to help the filament trough the pfte tube (used on Bowden setups), a few drops of oil will help a lot with the friction for months.
The second tip is even easier, do not keep the plastic away from its bag! but why? three main reasons!
- Dust will accumulate on it
- Humidity and air pollution will decrease the filament quality over time, it will break easier and this is a huge problem if you use bowden setup with corners
- Three: Sun light is known to crack plastic over time, thus decreasing its quality
Third tip: Research the manufacturer on the internet before buying, there are both good and terrible options, price doesn’t means anything! trust me!, once i’ve bought a 60$ filament, and guess what? it was terrible! a 10$ one from china was incredibly best.
Fourth tip: Not always clogging means bad filament, sometimes there is something wrong with the nozzle and the stepper, follow this checklist:
1 > Thermistor!
Check the nozzle temperature!, the thermistor might break or get loose over time, maybe it showing 200C but actually its 160C. check if it is okay. a laser thermometer is great for it. Warning! Loose thermistor are known to cause the printer to get on fire! This is extremely dangerous!
2 > Nozzle Cleaning
2.0 > Heat the extruder to 160C and remove the filament inside,
2.1 > Heat up the extruder up to 300C (don’t worry), and wait for 30 seconds after the temperature gets to 300.
2.2 > load filament in the extruder and try to extrude about 1 meter! (it will take some time), if there are failures you should remove the filament and try again from step 1. until it comes out linearly. Be sure that the extrusion speed is not too fast,
2.3 > If the filament is going out ok, try printing again, it should have worked. if not, you might need to open it and do a harder cleaning, with drill and some needles. try this tip a few times, remove and insert the filament and try to insert again.
3 > All-Metal extruder refrigeration
This is a common issue, the all-metal extruder is composed of three parts, Heat dissipator; Heat-break and the Heated block
The heat dissipator and the heat-break work together to keep the heat only at the block. a bad quality heat-break will let too much heat go up to the dissipator, which will get too hot and melt the filament where it was not supposed to and will make it jam. Make sure you use one with a PFTE core.
There is also the cooler! you need a good quality cooler to help the dissipator, if you don’t use one, this might be the problem
How to save a printing that is clogging?
First of all! pause the printing as soon as you hear the stepper motor skipping.
Pausing on LCD: do NOT pause on REPETIER! it don’t work fine and might lose the positions, you just need to navigate to quick settings then change filament *issue on 0.92, maybe its already fixed on other versions
Pausing on HOST: you need to locate the pause button in the host, after it pauses move the nozzle away from the printed part, a few mm is ok. now go to the lcd and navigate to quick settings then change filament. choose it
You need to remove all the filament from the extruder, now break some cm of filament, 10-20cm is ok, load the filament again and extrude at least 100mm of plastic, this will help to remove any dirt inside the nozzle.
After this, if the extruder is working fine, you just need to get out of the filament change menu, if you are on SD printing, the print will automatically resume, if you are printing with a host, click on resume and you are good to go (don’t worry about moving the head around,it will get back where it should)
Simply like this, you just saved a print!, you might have lost a few lines and maybe a layer, but at least it wasnt the whole print!