Blob of death with nozzle adaptor
I had shared my thoughts and experiences with the different kinds of nozzle swaps on the XL over in the Mk4 forum, where the question of Prusa nozzles vs adaptor had come up: https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-general-discussion-announcements-and-releases/question-re-nozzle-adapter-vs-full-nozzle-assembly/
With this update, I'm moving the discussion back here where it feels like a better fit.
I recently replaced the original 0.6mm nozzle with the adaptor and a tungsten carbide 0.4mm nozzle. Initially, things looked good but today the tell tale signs of a leak: big black blobs on the models. I should say that on my various Mk3S and Minis I have changed nozzles literally a hundred times, and I can count the number of leaks on the fingers of one hand.
So I disassembled the nozzle, and sure enough heater block and nozzle were baked in a thick layer of black crud. Took me a half hour with the heat gun to get to a point where things looked halfway decent again and I was able to screw the original nozzle back in. I was sure I had followed the instructions to a tee, but I guess there must have been gap with the sausage oozing out of the upper side of the heater block. And yes, I did hot tighten the nozzle with a torque wrench at 280 degrees…
Just when I convinced myself I would prefer the adapter and my trusted TC nozzles, now I'm wavering and considering buying a few Prusa nozzles, in case this is more than a one-off user error.
What makes this particularly vexing is the fact that you can't (yet) buy separate heater blocks. So I have to clean the one I have to continue printing and pray to God that I don't damage the cables.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blob of death with nozzle adaptor
When I moved to a tungsten carbide nozzle on my Mk3s+ I also swapped the beer block to a copper plated one. I had read beforehand that this was required due to the tungsten carbide nozzle won’t to hard to tighten and make a good seal otherwise…
I realise that perhaps doesn’t make much sense as the nozzle it being tightened against the heat break but that’s what I’d read anyhow.
and also it allows the nozzle to heat more like it was brass.
Im hoping a Prusa release a copper plated version the the heat block… or could you fit an E3D one?
RE: Blob of death with nozzle adaptor
Probably to do with things like thermal expansion of the different materials.
One other thought might be time to go the diamondback route so then it’s still a brass nozzle but suitable for abrasives.
RE: Blob of death with nozzle adaptor
I also think it's thermal expansion. This issue is actually quite common when using a V6 aluminium heater block with a TC nozzle. Google for "tungsten carbide nozzle site:reddit.com" and you will see quite a few comments about leaks with aluminium. The thermal characteristics are so different between these materials that the nozzle unscrews itself over time. Some people don't have this issue, some do. This is why I've changed my heater block to a copper one on my MK3S+ before I installed the TC nozzle.
I really hope Prusa will release a copper heater block. If not them, then some third party. I want to reuse my TC nozzle in a MK4 without risking a blob.
RE: Blob of death with nozzle adaptor
Sounds reasonable. I've been using Dragon hotends and never had an issue. I just checked, and indeed it uses a nickel-plated copper heater block.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
When installing TC nozzles on my MK3S+, I added boron nitride paste to the nozzlw threads. I was wondering if you did the same on your adapters?
RE: Blob of death with nozzle adaptor
I don’t know if it’s a good idea to use boron nitride on the nozzle threads. Afterwards it could be more difficult to change nozzles. Also, any residue of the paste migrating to the top of the nozzle might prevent a good seal between nozzle and heatbreak.
Just saying, but Slice Engineering recommends to apply boron nitride only to the cartridge heater and the thermistor.
RE: Blob of death with nozzle adaptor
When installing TC nozzles on my MK3S+, I added boron nitride paste to the nozzlw threads. I was wondering if you did the same on your adapters?
I did use thermal paste for the heat break on the Mk3S but did not use it for the nozzle on the adaptor. If it's a differential heat expansion issue due to material differences between heat break and nozzle, I'm not sure how thermal paste would make a difference as all it does is facilitate heat transfer.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blob of death with nozzle adaptor
To be honest, I hadn't really thought of it initially, but after reading some of the reviews of tungsten-carbide-reprap-m6-nozzle on the Spool3d site, I was concerned about leakage so I reached out to them and they are the ones who told me to use boron nitride paste to help "seal" it.
So ordered the paste and the nozzle and didn't have any issues. Maybe it was luck.. I don't know
RE: Blob of death with nozzle adaptor
Best resolution to this issue would be for Prusa (or rather E3D, since they're the actual manufacturer of these new Prusa hotend parts) to start selling copper heater blocks. The adapter, however... I have no clue what it's made of. I wonder if it would cause leaks even with a copper block in place... That threaded part looks like brass. I've never seen a TC nozzle screwed against brass, so I have no idea if it would cause leaks.
Honestly, the more I look at it, the more worried I am I might have to sell my TC nozzle for cheap just to recuperate some of the costs and go for something bi-material like a Diamondback... Which I don't like because it has the same issue as hardened steel nozzles, while TC had none. I wanted a nozzle that can withstand the most abrasive stuff I throw at it while keeping my brass profiles exactly the same, no changes necessary. A hardened steel nozzle is solving the abrasion issue, but requires upping temps to maintain the utmost quality. Diamondback? Same thing, but reverse - lowering temps is necessary, even more so than steel. TC was very resistant to abrasion and conducted temps almost the same as brass, which was perfect. But the darn thing unscrews itself very easily on aluminium...
Honestly, what should I do? I hate changing nozzles, TC was solving all my issues perfectly on a modded MK3S+, but if it doesn't stay put on the stock Nextruder hotend and Prusa doesn't provide proper parts for sale, what's the alternative? Is there any? I could deal with Diamondback requiring a complete overhaul of all my brass profiles, but the darn thing is even more expensive than TC and I have to pay 23% VAT on top + draconian shipping. First world problems, I know...
RE: Blob of death with nozzle adaptor
Sorry for the double post, I cannot edit the previous one. I've started googling for an alternative and I saw that E3D will release a V6 ObXidian nozzle in the future. I know that Revo versions are already in the wild - how do they fare thermals-wise compared to brass? I remember some old E3D info graphics claiming that ObXidian nozzles are resistant like TC and have thermals close enough to brass to reuse the profiles. Is it true for the Revo version?
RE: Blob of death with nozzle adaptor
E3D already make a copper heater block. Is this not conpatible?
RE:
For Nextruder? They don't.
They do for V6, and I already have it on my MK3S+. But I need one for MK4 as well to continue using TC nozzles without leaking. That or a new nozzle with similar properties.
RE: Blob of death with nozzle adaptor
Are the threads not the same?
RE: Blob of death with nozzle adaptor
Still trying to wrap my head around this… Why would the material of the heater block even matter? The only contact interface through which anything can leak is between the nozzle and the heat break.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blob of death with nozzle adaptor
The heater blocks threads is what keeps the nozzle held in. Due to thermal expansion at different rates the nozzle will become lose in the heater block.
RE: Blob of death with nozzle adaptor
Got it. So if the heater block slightly expands at a different rate than the nozzle it would allow for some tiny wiggle room for the top of the nozzle to disconnect from the bottom of the heat break. Makes sense.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blob of death with nozzle adaptor
Exactly.
As for the Nextruder, the threads are the same, but nothing else is. The design of the new heater block is different than V6, the heater cartridge + thermistor look different too. So I don't think it's compatible.
As a side note, I've been playing with the new IS profiles for MK4 today and I think I will get a Diamondback after all. The temp differences are big enough with these new speeds that I'd have to mod my profiles anyway and a Diamondback being so thermally efficient would actually be an advantage. Rip my wallet.
RE: Blob of death with nozzle adaptor
I don't know if they ship overseas, but this nozzle pretty much checks all your needs. We have 9 currently running on our Prusas and we constantly switch from TPU75A, 85A, PETG, PC CF without any issue. We use the same profiles on the printers that runs with brass nozzle and everything is going smoothly.
RE: Blob of death with nozzle adaptor
The new ObXidian V6 nozzles are out. How do they compare with the Diamondback nozzles? I bought the Diamondback on Amazon, but I might cancel it to save $50 if the E3D nozzle will fair better because the entire nozzle is the same rigid material, and the coating is applied through the entire surface, but the Diamondback is less prone to clogs and can print up to 30% faster due to thermal conductivity being higher than brass.