5 methods to unclog the nozzle of your 3D printer

This may be one of the most common problems you might meet with a 3D printer such as the Ultimaker2. Be realistic: the nozzle diameter is 0.4 mm, it’s tiny so it’s fair if it’s happening.

There are different ways to unclog it, but if the nozzle keep clogging, maybe you had to check something else in your printer.  In this post, again we’ll be focus on the Ultimaker2.

Atomic Method

One of the most efficient method is the Atomic Method. Follow the topic on Ultimaker Support website, it’s explained how to do it step by step.

It’s explained here to “Lower the temperature to 90 degrees (for PLA) or 110 degrees (for ABS)” (step 4). I tried ABS with 90 then with 110 degrees as indicated, but it didn’t seem efficient. In fact, it already happened to me that the filament breaks and exceed the heating block and it becomes hard to do this technic.

For this method, whatever the printer is clogged with PLA or ABS, I clean it with PLA. Be careful : I tried the atomic method using low quality PLA filament and it was the same result than doing it with ABS plastic.

To be more visual, here is a video about the Atomic Method:

In the comment section of the video, some people seem stocked and don’t now what to do because it doesn’t look efficient.

Sometimes, it takes time to remove the plastics residue of the nozzle, because there might be a lot of plastic in it. So it already happened to me to do it, like 20 times before being able to print again. But when it too much, then it’s time to do something else.

Well I use this printer since about a year and even if I didn’t get the time to experiment everything I wanted lately (especially because few days ago it was like  40˚C in Paris, too hot for 3D printing), I met enough clogging to make my own opinion on this. I think this method is efficient, but you had to be patient.

Korneel’s method

I discovered this method when I’ve got some troubles with the Ultimaker2. The method is fully described here, so I let you read the forum entry.

To be honest, I didn’t try this method for few reasons. First of all, when I tried to remove the nozzle for the first time, I couldn’t remove the screw which maintains the sensor and the cartridge inside the nozzle. Also, I didn’t (and still don’t have) a gas burner. Also, since the Ultimaker2 is a property of the University I’m working for, there isn’t good place to do it safely.

Nevertheless, it’s seems quite efficient, so it’s still interesting and thanks you Korneel to share your method. Maybe I’ll got the chance to do it later.

Blow torch method

Ok, so I was looking for a video (which is actually the one of the following point), but I found this one:

This quite crazy. I don’t have a blow torch, I don’t need one, so I’m not sure I’ll try it one day. It seems quite unsafe – especially for me because I don’t feel comfortable playing with fire. I didn’t try it and I don’t want, but if you’ve got a blow torch, maybe it is useful for you!

Acetone method

I found this video couple months ago :

It’s quite interesting because Eric William explains how important it is to clean the nozzle. Indeed, it’s acting directly on the printing quality. The method here consists to use acetone. Be careful again, this product is not really compatible with the two previous technics due to the use of fire and Acetone is highly flammable.

I tried this method as explained in the video. I let the nozzle in the acetone for few days (2 – 3) and it actually worked! To improve the cleaning, I remove the residue of plastic inside the heating block time to time so the product can be more efficient.

Smarty-pants method

This method is efficient as well, but I wasn’t gentle enough and I broke the two wires connected to the heating block.

First, unmount the nozzle following this video:

The thing is I wanted to do Korneel’s method but arrived at 7th min 50 of the video, I couldn’t remove this screw, even with a 1.5 mm hex key. With the help of springs, I unclenched the screw then I could remove it.

After, I let the heating block hanging with the help of the sensor and the cartridge. I heat it up to 180-250 degrees (depends if PLA or ABS). The plastic inside starts to melt and I can remove it using a needle. To have a better support, I hold the nozzle with springs.

Well, it’s working quite well but,as said above, I broke wires. I mean I thought the sensor was broken first, because the protection was damaged and the electric wires were visible. I was wrong, because when the PT100 B Sensor broke, the Ultimaker2 indicated an error on the screen. The heater cartridge is quite fragile and even if it doesn’t look so, it might be damaged inside.

The technic itself is well intentioned, but there is too much stress on the wires and I finally had to change both of them.

Those are 5 methods. Don’t know which one is better. I guess the best one is the one which is working good for your printer. Using Acetone is nice because it’s acting in all inaccessible part, but if you’re in a emergency and you want to clean it quickly, atomic or Korneel methods are better.

If you have any feedback to do, please share it in the comment section!
Also, they might have plenty of efficient methods I didn’t talked about, so you can share them as well!


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