Nozzle change on the MK4  

RE: Nozzle change on the MK4

They were referring to these parts on Printables:
https://www.printables.com/model/624027-mk4-nextruder-nozzle-change-heater-block-clamp
https://www.printables.com/model/571031-nextruder-nozzle-wrench-for-prusa-mk4
If you use them you don't have to detach the cable plugs from the Nextruder.

RE: Nozzle change on the MK4

One thing to keep in mind though.  You need to tighten the nozzle down good and tight, if it is not plastic will start pushing out the top of the heater and make a real mess.  First hand experience here...... 😬 

RE: Nozzle change on the MK4

I think this is a mixup of different things. This is not referring to the nozzle adapter for old V6 nozzles, because that part cannot be 3D printed and still requires hot tightening. The quick change process for nozzles is only possible for the Nextruder Nozzles, where the change is performed without heating the hotend. The printed tools (clamp and wrench) would not withstand a heated nozzle.

RE: Nozzle change on the MK4

This video doesn't use the same printable parts that  @walter-layher  mentioned, but it's the same concept.

RE: Nozzle change on the MK4

Posted by: @walter-layher

I think this is a mixup of different things. This is not referring to the nozzle adapter for old V6 nozzles, because that part cannot be 3D printed and still requires hot tightening. The quick change process for nozzles is only possible for the Nextruder Nozzles, where the change is performed without heating the hotend. The printed tools (clamp and wrench) would not withstand a heated nozzle.

Oh Yeah, got it.  I miss understood. 

RE: Nozzle change on the MK4

Posted by: @walter-layher

I think this is a mixup of different things. This is not referring to the nozzle adapter for old V6 nozzles, because that part cannot be 3D printed and still requires hot tightening. The quick change process for nozzles is only possible for the Nextruder Nozzles, where the change is performed without heating the hotend. The printed tools (clamp and wrench) would not withstand a heated nozzle.

I must have missed the part about changing the old V6 nozzle with a HOT hotend, no wonder it didn't work when I tried to use one of my old V6 nozzles.

RE: Nozzle change on the MK4

That link shows the change in the MK4, in the MK4s, with the new fan, it can no longer be used.

Posted by: @fabnavigator

This video doesn't use the same printable parts that  @walter-layher  mentioned, but it's the same concept.

RE: Nozzle change on the MK4

RE: Nozzle change on the MK4

I know that there are two prints that allow quick change of the nozzle: the one you indicate and the one designed by the Prusa guys. The second, due to the new fan system, is no longer useful. The first one, to which you put the link, I am not sure that due to the final nozzle of the fan, it can be used.

If anyone receives the Prusa MK4s these days, could you check it out?

Posted by: @walter-layher

They were referring to these parts on Printables:
https://www.printables.com/model/624027-mk4-nextruder-nozzle-change-heater-block-clamp
https://www.printables.com/model/571031-nextruder-nozzle-wrench-for-prusa-mk4
If you use them you don't have to detach the cable plugs from the Nextruder.

RE: Nozzle change on the MK4

Ah, I forgot that the fan and shroud are fixed now on the MK4S, so the clamp won't fit any more. But I am sure that somebody will come up with a modified version that will fit. There is a bit of space left between the heater block and the rim of the fan shroud.

RE: Nozzle change on the MK4

Well if noone does it, I'll have to design it when I receive the MK4s update 🙄 

RE: Nozzle change on the MK4

I expect as soon as more people have the new printers the modified or a newly designed part will appear. Until then you could just loosen the thumb screws, lower the hotend/nozzle a little bit and use the spanner that came with the original MK4 to hold the hotend in place while you change the nozzle. Since I installed an ObXidian nozzle I only need to change it if I want to use another nozzle size, which I do not need to do a lot.

RE: Nozzle change on the MK4

I came looking for the way to replace the nozzle too. I'm on with the support and they pointed me to the mk4 adapter. I pointed out that it doesn't fit because of the new fan and they said "you will need to [re]move the hotend and take the nozzle from there".

I pointed out that the mk4s blog post says "Swapping the nozzles is still extremely easy – simply loosen two thumbscrews (no tools required) and disconnect the entire hotend assembly, or simply use a 3D-printed nozzle adapter and swap just the nozzle (it takes about 30 seconds)." and they just pointed me to the step about pulling out the hotend to replace again. *sigh*

RE: Nozzle change on the MK4

😓 I think the Prusa guys are in vacation mode. 😜 

Posted by: @prusa3-55

I came looking for the way to replace the nozzle too. I'm on with the support and they pointed me to the mk4 adapter. I pointed out that it doesn't fit because of the new fan and they said "you will need to [re]move the hotend and take the nozzle from there".

I pointed out that the mk4s blog post says "Swapping the nozzles is still extremely easy – simply loosen two thumbscrews (no tools required) and disconnect the entire hotend assembly, or simply use a 3D-printed nozzle adapter and swap just the nozzle (it takes about 30 seconds)." and they just pointed me to the step about pulling out the hotend to replace again. *sigh*

RE: Nozzle change on the MK4

Gee whiz. compared to my MK3s, the nozzle swap on the MK4s is such a cruise!  I'm kinda surprised that anyone wants to crane under the hot end and fiddle where they can barely see, just to avoid disconnecting two wires. But, I know - we're all makers and natural born fiddlers, so I guess that explains it. We'll go to any amount of trouble to avoid a little work ha ha.

RE: Nozzle change on the MK4

The issue is: it could be less work even. The 2 plugs are of a type that is made for easy connecting and occasional disconnection/reconnection, not for frequent operations like changing nozzles. One of the wire sets, the thermistor, is pretty fragile. Routing the wires is unnecessary difficult. Somebody decided the most user friendly solution for the black wires was to have them behind black thumbscrews into a slot in a piece of black plastic,  the slot directed such that you cannot see it from the front of the printer.

It is really odd the new fan arrangement does not come with a replacement for the block you can put on to keep the heater block in place when changing the nozzle.

For use with the V6 adapter I would welcome a set of dedicated connectors so you can do the heating/tightening away from the Nextruder, say holding the heater block in a small metal vise. 

RE: Nozzle change on the MK4

Posted by: @efvee

For use with the V6 adapter I would welcome a set of dedicated connectors so you can do the heating/tightening away from the Nextruder, say holding the heater block in a small metal vise. 

Nice idea, but you might want to use some thermally insulating soft jaws on that vise (custom garolite?). Otherwise the metal vice will be a heatsink that would take ages to heat up.