Problem changing nozzle
Recently I've been "updating" my Pruza MK2/s kit and I've been using the same nozzle for 4 months now. It was a brass nozzle and I was able to get some very quality prints out of it. However, when I started to print some small parts with overhangs, I've noticed that instead of going down they warped up. Now usually when I see this it would be a good thing but the P.I.N.D.A. probe started to knock off the print from the build plate. I've done the standard procedure of trouble shooting by decreasing the build plate temperature and reapplying acetone but it still warps up and then gets knocked off. As I was looking trough the 3D Printing handbook, I read somewhere that if filament starts to come out and loops back around to touch the nozzle, which it was doing for the past 2 months, its time to change the nozzle.
So I followed the nozzle change procedure but I had a very hard time trying to unscrew it. I tried setting it to ABS, which I never printed with before, and it was still stuck on there. I gave up trying since I could see I was stripping the nozzle.
With this in mind I simply need help trying to take off the nozzle. I'm replacing it with a steel one I bought of e3d.
P.S. I'm posting this here because the MK3/S forum seems to be more active.
RE: Problem changing nozzle
The nozzle must be loosened at temp, E3D recommends 285c for the V6. And be sure you are righty-tighty lefty-loosy when maneuvering the wrenches (i.e., counter clockwise to loosen). When reinstalling, 3 mn is the proper torque.
RE: Problem changing nozzle
Your brass nozzle may be just partially clogged and not abraded yet. Cleaning it properly (a metal brush from the outside, several cold pulls to remove carbonized stuff inside and if that doesn't work, then a 0.4mm micro-drill and a 2mm drill from the other side plus a sharp needle to carefully scrape deposits off inside the conical part) may still revive it to original glory.
Nevermind, Tim is right that if you want to remove it, follow the E3D guide. Get a real 7mm socket wrench. Get a 16mm open end wrench. Both are rather non-standard, even in Europe, but will make removing a lot easier and damaging the heater block much less likely. Then heat to 285°C, the aluminium will expand much more than the brass, the block will loosen the grip on the nozzle, and the nozzle then can be removed easily. Keep in mind that the aluminium is rather soft at this temperature and so stripping the thread in the heater block is easy. Also avoid touching the heater wires with the wrench, they are bare and exposed where they enter the heater and this may result in some scary sparks and possibly even a blown fuse.
For putting the nozzle back, get a torque wrench, a digital torque adaptor (cheap on Aliexpress) or print one. Not enough tight can cause clogs, too tight can strip the thread, so doing it with a proper tool provides peace of mind. 🙂
RE: Problem changing nozzle
Hey, great news! I was able to change the nozzle with relative ez. I used the following tools below to change the nozzle. However I don't know if its tightened all the way since at one point it became very hard to turn without applying too much force. I'll reply if it works. 
RE: Problem changing nozzle
Its good, I also realize that it might of been the temp settings that caused the small parts to be knocked off since filament was oozing out but not looping. Thanks for the help 👍
RE: Problem changing nozzle
Hey, great news! I was able to change the nozzle with relative ez. I used the following tools below to change the nozzle. However I don't know if its tightened all the way since at one point it became very hard to turn without applying too much force. I'll reply if it works.
Be sure to tighten up while heated to 285C! Tightening cold may result in messy leaks.
Not to be judgmental, but your heater block needs a good cleaning. That black crud is likely to start flaking off into your prints. Hit it with a soft brass brush while you have it all heated up, taking care around the wires. Consider a silicone sock to keep filament from accumulating like that.
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RE: Problem changing nozzle
Thanks for the advice. You should of seen what happened to it one time while I was away from the printer. Any ways I think my problem is solved, now I just have to figure out why smaller parts keep getting knocked off the build plate. 🤔