Hotend disassembly & heatbreak stuck in the heatsink

This guide is for the E3D V6 Hotend on the MK-series. NOT FOR THE PRUSA MINI!

You can find the complete E3Ds assembly manual of the V6 hotend, which can be followed backward for disassembly. This is the stock hotend on an Original Prusa MK3S/MK2.5S/MK2S. However, as the manual works with brand new parts, it does not consider the changes that happen when being heated repeatedly to hundreds of degrees, again and again. Metal contracts and expands and thermal paste will turn crusty over time. Therefore there are some changes to the procedure when disassembling after a long time of use.

To extract the hotend follow this simple guide for MK3S/MK2,5S/MMU2S, and for MK3/MK2.5.

Disassembly

The assembly manual for the V6 is still optimal for most of this procedure, with a few exceptions. Moving backward, you are first removing the nozzle (at 280 °C) to release the heatbreak. However, this makes it harder to remove the heatbreak from the heat sink in later steps.

For replacing certain parts of the V6 hotend, like heatsink, heater block, thermistor, etc. you can follow our guide How to replace a heatbreak/heaterblock/heatsink (MK3/MK2.5).

As the heatbreak can be quite fragile, and its threads me be damaged if you try to grip it with pliers, we recommend that you unscrew the heatsink from the heatbreak, before removing the nozzle, which locks the heatbreak in place. A Heatbreak can still bend and break so do not unscrew it at an angle. A bend will create a whole range of printing issues.

After you have unscrewed the heat sink from the heatbreak, proceed with the E3Ds assembly manual, by heating the block and unscrewing the nozzle.

Too late, it is already stuck!

Follow this procedure to resolve the issue.

Without any heat, manually screw your nozzle into its threaded hole in the heater block.
Screw it all the way in, then loosen it back a full turn (as described in step 3 of the E3D V6 Hotend assembly) creating a gap of about 1mm between nozzle and block.
Then screw the heatbreak, with the attached heatsink, into the heatblock from the other side as far as it will go.
Tighten the nozzle with a pair of pliers and you now have a better handle. You can also grab this with pliers for some leverage when unscrewing the stuck heatsink.

6 comments

NKT

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8 months ago

The links to the manual are broken!
Useful info to add would be which tools to use - Allen key sizes, primarily - since everything is likely covered in melted and burned plastic!

Alessandro Pantaleo

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7 months ago

Hello, thank you for your comment! The broken links are now fixed for the newer version of the assembly guide from E3D.
For the tools info, I'd recommend referring to the other guide mentioned in the article, made from our side, the guide on how to replace heater block or heatsink, it can be used as a reference for hotend dismantling and has all the details.

KellisRJ

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almost 2 years ago

The link after "Disassembly" goes to a non-maintained page: "This Wiki is not looked after anymore :( Please navigate to e3d-online.dozuki.com for up to date and improved documentation. The link from that page goes to a "Site Not Found.

Giuliano - Official Prusa CS

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almost 2 years ago

Hello. Thank you for bringing this to our attention.

Miguel Barroso

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almost 4 years ago

I went to the E3D V6 assembly guide and they use a hotend sock made of silicone. Is it beneficial to use this sock on a MK3S hotend?

David

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almost 4 years ago

Hi Miguel! It may be beneficial under very specific conditions, for example, if you print with high-temperature filaments and a hardened steel nozzle, the nozzle tip doesn't cool down as quickly and the printed part is stronger. But it has disadvantages too, like it blocking some air from the print fan-shroud resulting in worse PLA and PETG prints. Some of the silicone socks also do not hold well on the heaterblock and tend to fall off.

ZachBourdeau

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over 4 years ago

Ben, I think the article you are looking for is here: https://help.prusa3d.com/en/guide/how-to-replace-a-hotend-mk3s_161575

BRSlicer

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over 4 years ago

Thanks zach but that page is for the mk3s. I found the page. It didn't work and my heatbrake is now stuck in my heat block. Then I was pointed to this page: Prusa Knowledge Base | Hotend disassembly & heatbreak stuck in the heatsink (prusa3d.com)And I really think that all of these pages should also be linked together.

BRSlicer

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over 4 years ago

I do not want to sound mean, but I want to point out some problems I see as an end user with my background. Keep up the good work! :)I WOULD like to see an article about dissassembling the hotend for Prusa Printers running default configurations. As a out of the box user, this entire page is confusing. I own an MK3 and I want to dissasemble the hot end. I clicked on a link that says "hotend dissasembly and heatbreak stuck in the assembly" The link is listed right next to other topics that all address Prusa products running Prusa configurations. Furthermore, there isn't a different link that addresses this issue for unmodified printers, so one would assume that this is the page where all of the information for hotend dissasembly.As a simple users: Do I own a V6? What is a V6? Are there pictures of the heatsink and heatbreak? Isn't E3D a different printer? Why are we referencing it on a top level topic page in the category of "Maintenance"? It says "This guide is for the E3D V6 Hotend on the MK-series. NOT FOR THE PRUSA MINI!" Ok, so we know that it is NOT for the Mini, but what is it FOR, EXACTLY? Maybe a statement such as "this article is for users who have replaced their OEM hot end with E3D V6 option." It has a bunch of printers listed as "relevant". I guess some people have installed custom parts, but right now, maintenance for the custom parts is the only help article for hotend dissasembly?I'm sure it's good info, but I think the page needs more background and info about the context, and I don't know if it belongs under "Printer maintenance". Maybe it should go under a section for V6 hotends or for modifications?

William H. - Official Prusa

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over 4 years ago

Hello Ben. The MK-series (Like the MK3 you have) has an E3D V6 hotend. This covered in the Handbook of your printer. I would recommend reading that back to back before taking things apart, as it outlines all the components on your printer.

E3D makes nozzles and hotends and dabble with printers, but E3D is a manufacturer, not a Printer. The Original Prusa MK3 (and MK2/S) has stock/OEM a E3D V6 hotend. The full disassembly guide you request is linked in the second line of this article and the first line of the first two paragraphs.

As is instructed in the text, this is just a small addendum to the official E3D guide on their V6 hotend.

BRSlicer

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over 4 years ago

OK OK OK first off, you are skipping over the point. What is your job? Is it to tell users to read the manual or to make your help page helpful? Because this help page needs improvement. It is a poor help page. It is the worst help page I have found in the kb. I do not feel like you understood my message. I am not telling you that I don't know things. I am telling you that your help article would be more clear and easier to read if you simply added "The v6 hotend, WHICH IS THE DEFAULT HOTEND FOR MK3 PRINTERS".And then the problem is gone. In fact, your response hopefully will give people in the future the information they need. It's a shame you couldn't be bothered to update the help page instead of getting in digs about reading the manual. A person is here because their printer is broken. They are not going to sit down and read the manual before looking up how to fix their printer. That's not how life works.And I'm coming from a place where I've written technical support documents and provided support for 10 years as a job. When in doubt, be specific.

William H. - Official Prusa

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over 4 years ago

This is mentioned in the first red box of the article, but I also added a line for it:)