How to change the nozzle
Hi,
this should be a fairly straightforward topic, with help pages etc, but I'm a little obsessive, and after reading the help and watching the prusa video, I have a couple of things that I'd like to verify first. I tried searching the forum but couldn't find an answer. I apologize.
Starting point is the help page: Changing or Replacing the Nozzle :
- Step 1 has us remove the print fan and the shroud, laying it on the x cables
- Step 2 & 3 have us unload the filament and then move the extruder up the Z.
Question: Can I assume this is a mistake, and do first 2 and 3, and then 1? (it has been requested this change in the comments a few weeks ago, but hasn't been done. As it is, it's confusing, and potentially one risks breaking the fragile fan wires, if the extruder moves around and one has placed the fan there)
Second source: how to replace the extruder nozzle video, by Prusa. This is a few years old, but still the only one out there, and frequently referred to. In the video, once the extruder is up and hot, they instruct (at 55 seconds) to "use the wrench to unscrew the heater block a little bit". This step is NOT mentioned at all in the help article (where they actually say just to 'hold the heater block and unscrew the nozzle". Is it necessary? I personally would rather NOT unscrew it, but what do I know?
Also notice how in the video both print fan and shroud are still in place and there's no mention of removing them. Can i skip then the original step 1 (which should be after 3) altogether???
I understand that this may seem trivial, and i'm sure once i've done it once i'll think it was all silly. But I like to have an idea of what to do before i do it, and those instructions are not that clear. I can see from the help article comments that i'm not the only one wondering. This is such a common thing to do, that i feel instructions could be better.
So... How do you do it? Thank you!
RE: How to change the nozzle
Its trivial until you get it wrong and your nozzle leaks. To try and answer your questions
Yes you would move it up and to position first.
Ignore the unscrew the heater block. This is bad advice as it has a tendency over time to alter the position of the heatbreak too. If the heatbreak moves too far up the nozzle cant seal against it inside the heatblock and you get a leak. Which will ruin your day.
Just grip the heat block and make sure it cant turn and then unscrew the nozzle (while at temp). Same when screwing a new one back in, just make sure the block cant rotate and tighten the new nozzle against the heatbreak at the recommended temperature (around 285 will do).
RE: How to change the nozzle
Thank you!
do you think it’s beneficial to move the print fan out of the way, or not? I saw both options.
I have a tool to hold the heat block still, so hopefully that will help with keeping it in place 🙂
RE: How to change the nozzle
As long as you can grip the heatblock then there is no need to remove the parts fan. I don't use a standard fan shroud so I remove mine but I also have my fan wired with a connector so I can remove it completely and swap in different ones for testing as and when I need to.
RE: How to change the nozzle
I tried today and chickened out 🙁
I was not able by myself to hold the heatblock and with the other hand unscrew the nozzle (which seemed pretty stuck). I got the impression i was counterbalancing the unscrewing with the other hand holding the HB, and it seemed the HB was moving, so i pretty much gave up, not even sure if i messed up something. It seems to be printing still ok, but i'll have eventually to change the darn thing...
It doesn't take much force once hot but it can be fiddly.. You might find it easier to use slimline tools designed to go in a bicycle saddlebag.
Cheerio,