Nozzle change is too complicated and dangerous  

RE: Nozzle change is too complicated and dangerous

There have been a few discussions of this topic somewhere in this forum, all along the lines that the "quick" change is not really that. I for one have damaged a thermistor cable on my XL using the official procedure by trying to squeeze it through the channel behind the fan. Since then, I've been changing nozzles on the Mk4 and XL using a procedure similar to the one used on my MK3S, by just leaving the hotend in place, holding the heater block with the universal wrench and unscrewing the nozzle in place. On the Mk4 that's super easy with the fan neatly folding away, exposing the heater block for easy access. On the XL, I have enough practice now to do it the same way, but it's a bit easier if you release the grub screw and drop the hotend down a little bit (without releasing the cables). Doesn't feel any less "quick" than the official procedure and I see less harm for the thermistor and heater wires.

RE: Nozzle change is too complicated and dangerous

Thanks for reply.

I have went through the forum and found possible resolutions to the point /2/ and /3/.

1. I have found a discussion describing performance of self-build assemblies ( https://forum.prusa3d.com/forum/user-mods-enclosures-nozzles/quicker-nozzle-swaps/) but I'm not going to go this way.
2. An user has posted a modified version of X Carriage  https://www.printables.com/cs/model/587007-mk4-x-carriage-with-wider-cable-channel?_gl=1*y22vhx*_ga*Mjk0Nzg5NTcwLjE2OTc5NzMwMTA.*_ga_3HK7B7RT5V*MTY5ODU3NDM4MS45LjEuMTY5ODU3NDQ5Mi41NS4wLjA.
3. An user has posted a modified version of Love Board cover https://www.printables.com/cs/model/539125-loveboard-cover-with-nozzle-swap-hinge?_gl=1*1j79l7r*_ga*Mjk0Nzg5NTcwLjE2OTc5NzMwMTA.*_ga_3HK7B7RT5V*MTY5ODU3NDM4MS45LjEuMTY5ODU3NDQwNy4zNC4wLjA.

I'm probably going to solve the issue by printing those modifications.

RE: Nozzle change is too complicated and dangerous

Take a look at these two parts:

MK4 Nextruder Nozzle Change Heater Block Clamp and Nextruder nozzle wrench V2

I just used them for the first time, and they work really well. No plugging or unplugging cables, just unscrew the nozzle leaving the heat block in place.

RE: Nozzle change is too complicated and dangerous

Take a look at these two parts:

MK4 Nextruder Nozzle Change Heater Block Clamp and Nextruder nozzle wrench V2

Or this MK4 Nextruder nozzle change tool

RE: Nozzle change is too complicated and dangerous

Agree on this. These make changing nozzles on the MK4 as easy as on my MK3 with the Revo6 hotend - provided you use Nextruder nozzles and not the adapter with v6 nozzles

Posted by: @tom-horsley

Take a look at these two parts:

MK4 Nextruder Nozzle Change Heater Block Clamp and Nextruder nozzle wrench V2

I just used them for the first time, and they work really well. No plugging or unplugging cables, just unscrew the nozzle leaving the heat block in place.

RE: Nozzle change is too complicated and dangerous

I'm still interested in the idea of being able to quickly swap nozzles by hand.  My idea was to cut the thermistor cable and install a connector designed for repeated connects/disconnects on it, mounted in an easily accessible place.

RE: Nozzle change is too complicated and dangerous

Have just completed the Mk3s+ to Mk4 upgrade.  All has gone well until swapping the standard brass 0.40 nozzle with the hardened version.  Did not remove the wires, just loosened the two thumb screws slightly to drop the heat block about 1/4".  In the process, the hotend sensor wires came right out of the sensor cap.  Is there an approved glue for reinsertion.  I get intermittent errors on the heatblock test, as the wires are not stable when reinserted.

RE: Nozzle change is too complicated and dangerous

I find that the easiest was to change nozzles on the MK4 is by just unscrewing the nozzle from the heatblock and screwing in the new one again. Much easier than plugging out cables etc. Apart from waiting for the heatblock to cool (after unloading filament) the whole process of screwing it out and back in takes maybe 1 min.

I would appreciate a faster and tool-free solution. But to be honest I don't find the nozzle changes to be a major point of frustration. 

RE: Nozzle change is too complicated and dangerous

I assume you have the V6 Nozzle Adapter, otherwise the heatblock is held in place by the nozzle itself.

However, for me, this is not the point. Coming from the Prusa Mini, I have swapped my nozzles regularly. My issue is, that I was specifically sold on the proposition, that swapping nozzles is easy on the MK4 - which is not the case. Some (including me) might even argue, it even more prone to user damage than on previous models.

Currently I'm satisfied with the solution I have posted earlier - and partially because assembled hotends are still out of stock. 

Don't get me wrong, I'm happy with my MK4. And I'm not one to throw around big words like "deceptive marketing." But I totally expect Prusa to acknowledge and fix this issue in some future Nextruder revision. In my view, there is no spinning this around. I didn't make them to describe this as "quick-swap nozzles" and I maintain my position, that the cable management is a major hurdle.

RE: Nozzle change is too complicated and dangerous

Posted by: @stuchlej

I assume you have the V6 Nozzle Adapter, otherwise the heatblock is held in place by the nozzle itself.

It's totally possible to unscrew the nozzle and let the heatblock just dangle by its cables while screwing the new nozzle in. Or, if one wants it a bit easier, you can always usethat MK4 nozzle clamp everybody loves. 🙂

RE:

the heatblock just dangle by its cables while screwing the new nozzle in

Seriously? 😑

you can always usethat MK4 nozzle clamp everybody loves. 🙂

I agree, this is a good workaround. This is definitely not how the printer is being marketed as.

It's as if a car manufacturer would present a car with new electrically operated windows. It would turn out, that it does not work (and didn't work at any point), but worry not - you can still 3D print a crank and crank the window down as you're used to. 

I'm not complaining that it is literally impossible to change a nozzle. I'm complaining that if Prusa markets is as a "quick-swap nozzle," we have a very different idea of what the process should look like. Maybe, just maybe, it should look like Prusa presents in their own marketing materials. Just maybe. And not involving any "3D printing" or "dangling components" etc. I don't think this is an unreasonable expectation.

RE: Nozzle change is too complicated and dangerous

Revo leaves the heat block and thermistor dangling

RE: Nozzle change is too complicated and dangerous

Revo leaves the heat block and thermistor dangling

Sorry, but I fail to see how this justifies anything. The marketing is quite explicit about how the procedure should look like: . No dangling involved. No "clips" etc. 

RE:

Posted by: @stuchlej

the heatblock just dangle by its cables while screwing the new nozzle in

Seriously? 😑

Seriously. 🙂

you can always usethat MK4 nozzle clamp everybody loves. 🙂

I agree, this is a good workaround. This is definitely not how the printer is being marketed as.

It's as if a car manufacturer would present a car with new electrically operated windows. It would turn out, that it does not work (and didn't work at any point), but worry not - you can still 3D print a crank and crank the window down as you're used to. 

I'm not complaining that it is literally impossible to change a nozzle. I'm complaining that if Prusa markets is as a "quick-swap nozzle," we have a very different idea of what the process should look like. Maybe, just maybe, it should look like Prusa presents in their own marketing materials. Just maybe. And not involving any "3D printing" or "dangling components" etc. I don't think this is an unreasonable expectation.

I agree in principle. The mechanism Prusa created is crap, the marketing is pure hot air and the nozzle change is advertised more complicated than necessary. We have no discussion there.

Yet, I don't think it's quite as bad as you put it. I have changed the nozzle multiple times using only the supplied tools (those two puny things) and it works without any issues. One could say that the documented procedure is totally brainless and that would be true, but the hardware as such works OK. Compared to the song and dance one has to perform when using V6 nozzles, it's still an improvement, albeit not the earth-shattering kind that Prusa advertises. Using that nozzle clamp it actually becomes quite acceptable, if you ask me.

Finally, one should not forget that Prusa is a brand for tinkerers. They are working towards the mainstream and I wish them all the luck they can have with that, but as of now, one should only buy a Prusa when a certain amount of screwing around with the device (pun intended) is acceptable.

The marketing is quite explicit about how the procedure should look like

Yeah, Hitachi's marketing also advertises the magic wand as a massager for your shoulders and the manufacturer of Q-Tips assumes that nobody will ever put them in their ear canals. 🙂

RE: Nozzle change is too complicated and dangerous

Hey guys! I really don't understand the fuss about changing nozzles. I'm new to 3d printing and what was my first thought? I have to buy separate heater block, heater and thermistor. So I have separate sets for each of my nozzle. Changing is very very easy. Even without a hinge or modified x carriage. Maybe its like that because I went through whole kit assembly recently. So this looks like easy now for me. I don't know. But it's really easy.

RE: Nozzle change is too complicated and dangerous

Wait until you've done the song and dance a few times. There will be a moment when you'll start hating the person who designed the "cable channel" on the Nextruder.