Hi @3DPrintMunich, I would like to try your sollution but the MK8 Heat Break For Copperhead seems to be out of production.
Any alternative you could suggest?
Hi Albert,
BR
Flo
The one in your image or the one in your link:
I have 2 piece of them, and may some other parts u may need
the transfernow link has expired, could you please repost
hi, is there any alternative to the Bondtech MK8 heat break? Because itâs out of production. Another question, do you think your setup can work with the Trianglelab MK8 nozzle without modifying the CNC Kitchen adapter?
I have been running my âall copperâ modification of J1 hotends since mid-June ( I guess I posted it here 19th of June or so) without a single heat creep clog, using various PLA filaments and over 40 kg of filament has been molten. So far so good 
Looking at disassembled J1 hotends in my drawer some soulful sadness came over me so I decided to give a try to recover original J1 design. Heatbreaks look rather well made, pity just let them be scrapped. It was visibly clear Snapmaker assembly staff has made great economy on thermal paste - it was almost none present. So I used all original J1 hotend parts, just installed heatbreak with rich use of boron nitride paste from Slice Engineering ensuring threads of heatbreak are in well thermal contact with aluminium heatsink. As I had one LDO fan available, I replaced original XYJ24B3010M with that one. The main idea was to eliminate fan noise as LDO fan is rather silent.
The only thing I finally did on the very printer is in picture attached - I did cut free air path into the encasing of toolhead. I was long time about to do this as it is clearly noticeable rhythm of plastic grid does not match with rhythm of cooler fins so air flow is heavily blocked due to this mismatch. So now air has free flow and full potential of tiny 30x30mm fan can be used.
To tell the truth - I am positively surprised with result. Already 6 kg of different PLA has been printed, most of the prints 6-7 h long, the longest yet has been 15h and hotend has been working flawlessly indeed - no clogs at all. I tried to use high temperatures of 215-220 C just to see it this hotend design fails. It did not.
Probably if Snapmaker staff has made their work on hotend assembly with due responsibility and air flow blocking design of toolhead case has not been used many of us have had been saved from nasty heat creep problem on this printer too many owners of J1 have been facing.
If I am not mistaken, the removal of the air grille was done before. I had this tested as well and it did not actually do anything. (edit: I had also tried back then to swap out the fan with the more powerful variant you can buy as a spare part from E3D. That did not help either. If the grille would have been the issue, this would have had some positive effect.)
But adding thermal paste does and did indeed help (which is why it is noted in the âthings to do first with J1â thread here), even if it did not cure the issue 100%.
If doing so suffices, depends in the filament you use, and on the retraction settings.
Thus: add thermal paste first, that is always a good idea. If that is not enough, consider changing the heat break, use another filament or reduce retraction. The latter one is what Snapmaker did in their software and Cura plugin at some point.
@Mechanikus. I completely agree thermal paste does most of the trick here! In my case it turned out to be sufficient cure as after another week of 24/7 operation on not the easiest PLA I have had zero clogs.
As for myself I did grille removal only now but for sure I am not pretending to be the first one doing this. Even it does not help a lot I do not see a good reason to have it there as any excessive resistance to air flow at its outlet will facilitate increase of overall temperature in the most critical part of heatsink. So letâs put it that way - even if it does not help at recognizable level, it will not harm for sure.
I have been running my SJ1 now for several weeks in Frankenstein mode - both extruders in copy mode all the time, just one of them is modified with Copperhead heatbreak + MK8 nozzle and the other one as recovered original. The copper one has better thermal inertia but apart from this both work flawlessly now.
The most likely I will recover second original hotend too and use vacated modified ones with Copperhead heatbreaks to be fitted with AP3X GammaMaster nozzles from SliceEngineering. Letâs see how it will turn out.
I donât know if removing that grille (or rather the lowermost part) might direct additional unwanted air flow towards a part if both hotends operate closely together - but apart from that I fully agree that it will not cause any harm 
When it comes to filament, my personal impression was that the original hotend had its very own thoughts about which filament it might like and which one might be difficult - and as noted, it highly depends on the retraction amount.
All in all, it is really great that it works for you now! But I do not trust the original variants and would therefore keep at least a set which I could quickly swap in case of issues.
@Belvis you seem right - that is really sad! I had hoped Copperhead would keep those :-\
Apart from the nice coating only Copperhead uses which helps to reduce the issue, I guess any bimetal heat break should work - you only need to adapt the length of the spacer since the Aliexpress clones seem shorter than what Copperhead has designed.
Take care though: there are two variants of those: one is âcopper heatsink thread - stainless or titanium pipe - copper heatblock threadâ (sold e.g. by Bigtreetech), while the other and seemingly cheaper one is âcopper thread - stainless or titanium pipe and heatblock thread in one pieceâ.
Judging from what we found to be the source of the issues, my stomach feeling tells me to probably avoid the latter ones.
@Mechanikus I completely share the points you stand! I âreinventedâ original SJ1 hotend for myself just because of sudden engineerial curiosity with no particular expectations on result. Even better when result seems to be on positive side
But I am still surprised Snapmaker J1 assembly staff has not used thermal compound almost at all. Or they have invented some very special one - with completely disappearing traces of application 
That stuff is not new or special, it is called âwaterâ. Cheap and quite capable of transferring heat, but only below 100°C in such an unsealed system⌠and it has a bad tendency to simply disappear over time, leaving almost no traces⌠fits perfectly to what you found, doesnât it? 
could you post a link to what you would recommend getting from AliExpress?
@Belvis as far I can judge from pictures alone (I have the original Copperhead heat breaks in all my J1 hotend inserts), the MK8 variant of this one looks as if it might do the job: https://de.aliexpress.com/item/1005004521472527.html
But, as noted, you need to make the spacer slightly longer for this one if the dimensions noted in the offer are correct. The original Copperhead heat break has 27mm length.
thanks, Iâll ask you one last question⌠having the Slice Engineering thermal paste, can I put it on the heat break also on the heat block side?
@Belvis I would avoid thermal paste on heatblock side of heatbreak at least due to two reasons. The primary: as less heat is transferred into heatbreak as better (we need to keep heat away from it as much as possible) and improvement of thermal transfer from heatblock to heatbreak is to be avoided. The secondary: any tiny residue of thermal paste there might get compressed between heatbreak and nozzle. Tiny gap there will form a pocket where molten filament can flow into and create unwanted resistance to filament flow up to risk of clogging. In case you need to do cold pull this brim around filament can be that strong you tear off filament somewhere in heatbreak leaving part of it in nozzle thus running into even more trouble.
I would suggest to do âdryâ assembly (no thermal paste) of hotend first just to be sure all parts fit mechanically and are within needed dimensions and do it just by force of your fingers and if everything fits well, go on with final assembly using thermal compound.
When applying thermal paste on heatbreak-heatsink joint use old rule of woodworking - put glue into hole, not on the dowel = fill about 10 mm of thread of heatsink with paste from the hot part of heatsink and, of course, paste on external thread of heatbreak as well. When screwing heatbreak into heatsink, observe rib of excess paste that will form on heatbreak when threaded joint is squeezing paste out. When rib is there, screw heatbreak out for 1-2 turns, re-apply that excess paste evenly around the remaining protruding part of heatbreak thread and do it several times, every time going 0.5-1.0 turns deeper until you reach desired position of heatbreak. If paste has been applied filling threaded part only with no excess, all of it will go into thread and form a good thermal between heatbreak and heatsink. Clean filament path with some piece of filament with square as possible end - just to be sure there is no paste remaining in unwanted places. If paste residue will be pushed into nozzle, it can form a very nasty clog, hard to remove thoroughly.
I was looking for nozzles to use with abrasive materials⌠the Bondtech CHT MK8 Bimetal have a totally different shape from the originals and Iâm afraid that they will cause alignment problems between the 2 extruders, am I right? I would have found these,
https://a.aliexpress.com/_EjRsgVL
but they leave me highly doubtful because they seem to be made backwards with the copper part inside, so I imagine they would be abraded just like the normal ones, am I right?
I also use this MK8 and have had no problems.