Change dead nozzle

[dahunter 0]

Hi guys,

I have a Ultimaker 2+ extended here in our company. Sadly the 0.4 nozzle is gone and all attempts to change it failed. Yesterday we even tried pliers.

 

The tools that came with the printer did not work, nor proper new tools from the tool shop. The provided tool and the nozzle have rounded edges.

 

Is there any way to remove the nozzle in such cases?

 

Thanks for your help.

[SandervG 1,519]

Hi @dahunter, welcome to our community. 

Perhaps it would be helpful if you could provide a photo to illustrate your situation.

 

First thing that comes to mind if it is indeed ruined and completely round; could you flatten two sides on your nozzle with a tool (like a dremel?) to give more grip to a pair of pliers or something?

[dahunter 0]

Thanks for the quick reply!

 

I just changed the nozzle. It looks like as it was changed before and not properly turned into the print head, plastic went into the coil and backed there.

[SandervG 1,519]

Good to hear you managed to solve it. It is an always a good idea to replace nozzles when they're hot. 

[yellowshark 153]

Lol thanks @SandervG I want to change a nozzle at the weekend and was about to ask that question - a long time since I have changed one and memory was letting me down!

[gr5 2,094]

I was going to say - heat the block before changing the nozzle as plastic can act like threadlock.  150C is plenty warm for this purpose.  Now that you have some plastic in the threads you will have to do this going forward.  Forever.  But don't worry - it's no big deal.

 

If you do damage something you can always get a brand new Olsson block.

 

[SandervG 1,519]

But I thought you didn't have an ultimaker, or do you? Thought I read that recently. (Shouldn't necessarily stop you from replacing someone else's nozzle.. if they consent :p) 

[yellowshark 153]

 Hi @SandervG, was that aimed at me? No I do not I have a 3ntr and that is the printer I want to change the nozzle on; I could just not remember if it was best done hot or cold. Indeed the 2nd or 3rd time I did a change the nozzle broke off the screw thread which cost me a new nozzle and extruder, so I certainly would not offer to do it for someone else without a cast iron contract!!

[SandervG 1,519]

yes, sorry that was aimed at you. And why hot / warm? (I always find things easier to remember when I know why. Otherwise it is just this random disconnected piece of information). After you have used a nozzle in your 3D printer, imagine that not just the nozzle, but the chamber above and most of the hot end are still full with solidified filament. Doesn't really matter if it is PLA or ABS or whatever, but it ensures a proper seal and makes you apply a lot of pressure getting it lose. Which comes with a significantly increased risk of breaking your nozzle or other part of your hot end. By heating it up you melt or depending on your temperature, soften up the filament inside and it will be much easier to replace the nozzle. That is why it is better done hot. 

[yellowshark 153]

Thanks that is really helpful and what you say makes a lot of sense. I suspect I was impatient and did it cold when I broke that one

[dahunter 0]

Another idea to change a nozzle is to drill a hole sidewars through it (2mm). Then you can use a 30-50mm M2 screw to turn it.

 

One last question: Is there a chemical/liquid to remove left over plastic in the coil?

[yellowshark 153]

I am not sure quite what referring to with the word "coil" but I have had, on a couple of occasions, needed to remove filament from the inside of the nozzle's threaded shaft and have just used boiling water to soften the plastic then scraped it away. I use isopropyl alcohol to remove filament off a hot nozzle but I do not know if it would clean off cooled plastic chemically.