@Karass3D That copper heatsink looks nice.
Would you share the step or stl file?
Might give it a try.
@SnapSnap
Heatsink_SJ1_v2.step (305.7 KB)
Here you have it! I had it originally as dxf and made *.step only because of posting rules here on forum. Using dxf contour only I made it from 10mm piece of copper slab by wire EDM technology, 0.25mm wire used. Copper cuts like charm that way - fast and very precise.
I have no bore for heatbreak and top adapter in particular STEP file disclosed. First I made D5mm pilot hole all the way trough heatsink and then threaded from both ends length necessary for thread to be matching my taps and also the pieces to be accommodated. That way spacer between inlet adapter and cold part of heatbreak is centered by D5 bore, not tip of the thread. This gives extra centering precision for spacer. D5 bore and piece of stock D5 copper bar fits perfectly!
If I would need to make this heatsink again I would make some 3-4mm extension on bottom part to cover also protruding piece of heatbreak - the most dangerous one for heat creep. But be aware to be able to reach deep enough with tap you use! M6 taps are somewhat dangerous - shank might be a bit larger than thread making part. Needless to admit - any drilling and threading in copper only with cutting oil applied!
However there is another path to follow instead of modifying heatsink - to accommodate piece of silicone or ceramics around that protruding part of heatbreak to protect cold part of it from radiated and convected heat that comes from heaterblock (top part of it is still open regardless of stock silicone sock around). Such an approach shall be verified, I have not tried it. But it can allow protruding part to be cooled even better exploiting great thermal conductivity of copper on particular heatbreak.
But to tell the truth - I am working now 12-15 hour jobs on a regular basis with my âalfa versionâ (as published) and since this modification I never had any clog using PLA. And I am working with both extruders in duplication mode all the time. I would avoid to use mirror mode without some trial prints because then both printheads from time to time are coming too close so heatsink cooling fans blow warm air one into the other. In duplication mode they keep constant distance and thermal balance within printer housing remains stable.
In addition I print with 52 Celsius temperature on print bed, the PEI side, to avoid unnecessary generation of heat, top and doors open, no additional fans anywhere.
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Hello Jade
Thank you for the update. It good to see that you are taking action on this very serious issue. I suspect your real issue was poor manufacturing. I notice as i was cleaning a clogged unit there seem to be some burrs on the heatbreak. I took a drill and gently removed it as best as I could. I also checked the other set of heads and noticed the same problem. Removing the burrs and reducing speed seemed to eliminate the problem for me. However I would like to get back to full speed printing and therefore eagerly await for solution that has been thoroughly tested. Please update us any progress you make. Thanks.
Would have been nice if it had been just such an issue, but rest assured checking the inside of the heatbreak was among the very first things I did when I had these clogging issues. Mine looked perfectly - almost mirror-like inside, no chips or burrs at all⊠the clogging happened nevertheless 
@Karass3D Thanks for the files and the detailed description how you made it.
EDM is not in my toolset. Can only do CNC routing. The slots are very narrow. 1.5 mm router bits usually are not long enough to cut stock with 10 mm depth. Ordered a special one with 12 mm lengths. Do some tests with aluminum and if that works will try copper.
@SnapSnap Copper is very nasty when chips to be made. Easy to ruin drills, router bits, taps because chip is very plastic and tends to clog flutes of tools. I have different experience in machining copper but still the collected one tells do not try it dry - some oil containing mist coolant suitable for copper (some can blacken it) will help to be on safe side.
1.5mm router bit in 10mm depth is sort of challenging so I wish you success!
Hi there,
I have installed the GammaMaster AP3X 0.4mm. It does work well for all the calibration steps.
My setup is a kind of a mix of what has been suggested by @3DPrintMunich and @StephenM.
- Bondtech MK8 Copperhead heatbreak
- GammaMaster AP3X 0.4mm
- CNC Kitchen Volcano Adapter Version 2
I had to shorten the Volcano adapter to about 6 mm. For this I have used a lock nut, inserted the volacano adapter âbottom-downâ until it was blunt. Then I used a metal file to remove the part above the nut. Make sure you keep the part of the Volcano adapter with the hole for the Allen key.
I just printed the XY belt calibrator with eSun Gold silk PLA: no issue but I had no issue before as well.
Then I tried a calibration cube with FilaFlex 60A and it printed very easily. Before I had a lot of troubles printing with this flexible filament. It was clogging randomly. I suspect this was some kind of heat creep as described earlier.
Iâve not tried abrasive filaments yet.
So far I just upgraded the left hot end. Iâll do some more tests in the coming weeks. If anyone is interested I can post some pictures as well.
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I posted this on FB group, but wanted to share this here too.
Top to bottom:
Custom steel spacers, 2.3mm ID, 4.8mm OD, 5mm long.
Copperhead heatbreaks
AP3X GammaMaster 0.6 nozzles.
All assembled with Slice boron nitride paste.
Everything is printing well now.
Hereâs a sample print, two-material, PLA and TPU print-in-place assembly. Great result.
Source: IDEX one-piece robot hand by Tsukasa-3D - Thingiverse
Cheers,
Stephen
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@StephenM. Seems I have been indirectly influenced by your approach as few days ago got AP3X shaped GammaMaster 0.6 nozzle too to give it a try in my SJ1.
I am using my iteration with copper heatsink, Copperhead heatbreak and MK8 0.4mm nozzles on both extruders for several weeks now and run printer on PLA 24/7 with 11.5 h print jobs in duplication mode. Not a single clog so far.
Just nozzle calibration using MK8 fails for about 0.05mm on X and 0.10-0.15 mm on Y axis. Not disturbing me in particular but still not OK. Could be because of more fat shape of MK8. GammaMaster AP3X seems to address nozzle form factor better, letâs see later if it helps.
@Mechanikus I am experiencing an issue a LOT which I think is what is being described here - not with silks, but with PEBA (A flexible that is derived from Nylon). Typically I have been printing this material on the right extruder (With Nylon in the left extruder) and with pretty high temperatures (240 left, 260 right, and 100c bed with enclosure closed - it is reaching up to 45-50c inside the enclosure)
I get the dreaded âclack clackâ sound on the right (PEBA) extruder a LOT - recently to the point where I cannot even get one 1.5hr print done before it completely jams up.
I have recently started loading the left extruder with PEBA instead, which seems slightly better, but after having done that for a few days, the left extruder seems to be deteriorating too and itâs happening more frequently on that now.
Anyway, to the point of my post - what exactly is the âclack clackâ noise? Is whatever causes it damaging the printer (eg gears or something)?
@evilC The âclack clackâ sound has two possible causes:
- the extruder stepper motor skips a step which will be heard as a âclackâ
- the extruder gears slip on the filament which may also cause a similar sound.
Please note both of these have the same basic reason âtoo much counterforce from the hotend onto the filament for the extruder to overcomeâ. This causes the extruder to fail to drive the filament forward. In both cases, it should be unlikely the printer will suffer permanent damage, at least judging from my personal experience - but your print will suffer for sure.
Thanks. I just used a marker to put a line on the axle of the gear - ie when the printer is extruding, I can now see the line rotate. When I hear the sound, the line stops rotating, so I am guessing this means that in my case the sound is the stepper motor skipping a step?
Exactly. Your extruder gears are fine and grip the filament you tested reliably (otherwise your marking would rotate) - but the stepper skips one step for each âclackâ since it would need more force to move the filament forward than it can create. The most likely cause for this is the unfavorable melting zone of the original J1 hotend as described in the first post; the extruder itself has plenty of power.
Right, when the stars align, I am able to print this material at ~50mm/s
When things are going horribly wrong, I have seen it struggle at 5mm/s
I am just fiddling with it now, and it seems that massively slowing down the deretraction speed (I have minimized the retractions as much as I can, but I need some) and extruder acceleration can significantly alleviate this issue - which seems in-line with the theory that itâs the melt zone not performing properly
Yes, that fits to what we found when we did our tests 
But it is interesting to read that this also happens with high temp materials to such a degree. We did not test those. I can only suggest to replace the heatbreak and nozzle as noted above - AFAIK it does not seem to matter if you follow our initial solution or one of the alternatives others created from what we did. I had not a single problem ever since.
I am tempted to try your mod, but I am certainly not capable of fabricating the parts myself.
Do you know of anyone who could ship to the UK who could make them for me?
Am also thinking of maybe just putting up with it for now and waiting for the mod that Jade mentioned, but this whole âDoing away with threadsâ bit she mentioned fills me with dread. It sounds to me like it will be proprietary nozzles, which is moving in the exact opposite direction I would like to see things move.
The one thing that slightly puts me off your mod is the mention of the calibration being more finnicky - itâs already not really that great for me as-is. I need things REALLY precise, because the parts I print suffer extreme physical abuse (Drone crashing into wall at high speed) and any mis-alignment impacts robustness significantly
Theny maybe try the variant some posts above first - that one uses an adapter you can buy instead of the self-made part. And the nozzle comes down further with that one as well, which means calibration becomes easier as well.
Edit: scroll up to post 133 (from 3DPrintMunich) if I just looked correctly - that is the variant I meant. Just be careful when it comes to assembly - you tighten three threads in a series in that case which means you need to take care the heatbreak is actually locked in place.
The AP3X nozzle mentioned in the posts above that one might further simplify calibration since they also seem to feature a 90° cone as the original nozzle.
Can you clarify this please? Is this talking about solely the CHT nozzle configuration, or both configurations?
Take the MK8 instead of the MK6. Then you donât have to shorten anything.
Are you folks using this heat break and nozzle as direct replacements for the stock ones? Would love to see some photos of this in action