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how hot does the heat break normally get?  

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neroes
(@neroes)
Eminent Member
how hot does the heat break normally get?

hi i'm assembling my hot end from new parts after a larger blob swallowed the last one

so i'm wondering what temperature does the thermal paste on the heat break need to handle

i mainly print pla and petg (215-230 Celsius)

Napsal : 09/05/2019 1:43 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: how hot does the heat break normally get?

The part in the Cold end  heatsink shouldn't get very hot at all

the part in the heat block will get much hotter... so I use coppaslip on the heater block threads.

 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Napsal : 09/05/2019 5:16 pm
neroes
(@neroes)
Eminent Member
Topic starter answered:
RE: how hot does the heat break normally get?

i was looking at Céramique™ 2 or Arctic Silver® 5 since i also need some for my desktop

doesn't coppaslip ignite fairly easy around 200 Celcius? i know the fan and all that should keep it cold but it does seem like a possible fire hazzard.

Napsal : 09/05/2019 6:36 pm
Chocki
(@chocki)
Prominent Member
RE: how hot does the heat break normally get?

I also use just a little smear (Think large grain of rice) on the threads going into the heater block and on my nozzle thread, wipe away any excess especially from the top of the nozzle (Use the edge of a paper towel to get into the gap), then as Joan advised me previously, put some paper towel underneath and bring the block up to temperature. If you have put too much on, the grease portion will melt and run out leaving a copper film behind which is not flammable. Also run some filament through, ideally a light colour (white) to purge any that may have got inside.

The part in the cooler will only get up to about 60 maybe for the first 1mm, then it should be ambient. the hotest it is likely to ever get, is if you lose power and the cooling fan stops, then heat from the block could creep up the heat break, but even then, I doubt you would see more than maybe 100 for a short distance and not for long. I have not heard of anyone ever having reported of an issue with the standard white stuff which the assembly comes with, this is just bog standard titanium dioxide based heat transfer paste, sometimes called metal oxide thermal paste.

 

Using ceramique or AS5 will not be a problem.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Napsal : 09/05/2019 7:10 pm
Chocki
(@chocki)
Prominent Member
RE: how hot does the heat break normally get?

This forum is driving me mad, time to edit way too short.

Using ceramique or AS5 will not be a problem in the heatsink end, but as Joan states and I concur, you are better off with a little coppaslip in the heater block, just not too much.

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.

Napsal : 09/05/2019 7:19 pm
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(@)
Illustrious Member
RE: how hot does the heat break normally get?

I just used normal Thermalloy Thermalcote paste, and it's working well. Thermalcote is rated to 200c.  By contrast, the  Arctic Silver paste is only rated to 180c. 

Doubtful the 20c difference is problematic since the heat sink should never get that hot, even the at lowest thread where the heat break enters. Most of my empirical experience shows the heat break is below PLA melt point just above the  heater block.

 

Napsal : 09/05/2019 8:33 pm
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