re-order received today 
, not tested yet
Your received the order very quickly 
@DzzD did you made already some tests with the new nozzles?
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Iāve been using the steel cht clone nozzle for the past 2 weeks. PLA flow for Polyterra starts showing defects at 34-35 mm3/sec. Petg around 20-22. ABS I havenāt tried maxing the flow yet but prints great at 25.
In general I did notice some leakage from the nozzle threads. Quite a bit of tightening solved that. Other than that it works brilliantly.
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I started a flowtest a few min. ago. The PLA leaked out of the silicone sockā¦ The thread was full of filament. Cleaned the nozzle and saw that:
I did not found the missing part. IDK if it was out of the factory
Maybe a little too much torque, or a too low temperature when you screwed the nozzle ?
I think I read somewhere that It is recommended to use about 275Ā°c when mounting/screwing such nozzle
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I think aluminum and steel have very different expansion rates. IIRC, its about double (aluminum expands around twice as much as steel), so if it where put in cold, I would think the aluminum would crush down on the steel (while the steel is pushing out). And if this was done cold, you could easily over tighten it when there are no expansion forces in the aluminum and have a problem after they both expand.
Just a guess though. Anyone else know the thermal physics behind it?
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I never changed a nozzle cold. I always heat the block and nozzle to round about 300Ā° with a heat gun before screw them together. But it doesnāt matter - can happen and there is always the first time xD
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Well, maybe this particular nozzle was having a micro crack, we will see with more user if it happen often, still not tested mine.
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For true bontech CHT Nozzles they recommend at least 280-300C before tightening and not too much force. Or at least above 250C, anything below that will lead to problems.
1.5newtonmeter for CHT Mos (brass) and 1 for CHT BiMetal. So yeah it might be a manufacturing defect or overtightening.
I have started to test the Hardened 0.6 CHT nozzle and it works great but require some tuning. This is printing nearly 25% faster for objects that does not requiere small details, using 0.3mm layers height.
Some issues / requirments I found for now are :
- need to reduce flowrate from 35mmĀ³/s to 30mmĀ³/s for Sunlu PLA+ (not tested other PLA yet like eSun PLA+, I will do)
- increase printing temperature by 5Ā°C to 10Ā°C
- need to reduce outer walls acceleration from 5000mm/sĀ² to 1000mm/sĀ², seems that corners with 0.6mm nozzle work a lot better with a lower acceleration, even if 5000 works very well with 0.4 nozzle
- for an obscure reason need to disable slowdown on overhang, that give better results on overhangsā¦
I will do some more tests and try to get the best from this nozzle, but it is already really pleasant to be able to print that fastly big objects, like boxes or others.
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New Hotend is out on Aliexpress, V2.
Please provide a link - there are zillions of sellers on Aliexpress. āV2ā of course means the same as āupgradedā in product descriptions - nothing.
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That item does not have CHT nozzles. The description is similar to a kit I ordered but had to return (was supposed to include CHT nozzles but didnāt.)
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very nice, nozzle change will be easier that with previous version
Please clean your Ali Links (we dont need the tracking information). Remove all characters after ?
https://de.aliexpress.com/item/1005005742658746.html?
or better is the EN Version for all here: https://www.aliexpress.com/item/1005005742658746.html?
I dont like the V2 design. Okay it can be more reliable. But the larger contact surface to the heat sink is bad for heat creep.
The heat sink is already very small and I think the small 30mm fan we have cant handle the additional heat creep in the closed printhead.
I had no problems so far with the V1 design.
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I did not read whole thread, but at the beginning, there is talk about heigh issues - I assume this has been fixed, because there are special Bambu CHT nozzles, right? I have purchased few, plus hotend that allows me to use them. But, there are no steel CHT nozzles available, or?
EDIT: I found steel CHT 0.4 and 0.6. Guess they have made them since I checked last time. Are there also 0.8 steel and bigger ones, such as 1.0 and 1.2? If anyone knows. Thanks!
I bought the hotend with 0.4 and 0.6mm hardened steel nozzles from AliExpress here and can confirm they work great.
There is a 0.8mm hardened steel nozzle available there but I do not have that one.