Replacing the Heat Break
Hello,
I just received my i3 MK3S kit in the mail. Preemptively, I've purchased an original E3 V6 heat break to replace the modified one that comes standard with the Prusa MK3. I have zero plans to ever get the MMU2 and after reading and watching many problematic posts and videos I decided it would be best to get a head of the jamming problems.
I wanted to replace the heat break before assembling the printer. My idea is to simply unscrew the heatsink to access the heat break, instead of removing the nozzle and heat block. I'm wondering, will I have to heat up hot end in order to take off the heatsink? Or should it unscrew fairly easy on its own?
P.S. I also picked up some thermal paste for the replacement.
Thank you for your help!
RE: Replacing the Heat Break
you will need to heat it up as it's installed at the factory at 280C
RE: Replacing the Heat Break
Just what I needed. Thank you so much!
RE: Replacing the Heat Break
But, why replace a V6 Heat Brake against an equal one? There is nothing to win from it.
What would be better with the new component?
I don't think you will experience any difference between them. 🙁
Bear MK3 with Bondtech extruder
RE: Replacing the Heat Break
I'm not going to pretend to be an expert, but my understanding is the heat break for the MK3 is designed differently than the original E3 heat break to aide with the MMU. This causes PLA to jam, especially with more frequent retractions.
This is sums up the issue and solution I've read in other places, including here:
RE: Replacing the Heat Break
But, why replace a V6 Heat Brake against an equal one? There is nothing to win from it.
What would be better with the new component?
I don't think you will experience any difference between them. 🙁
Pruse vs E3D-V6 original:
Prusa has E3D drill the bore to 2.2 mm down to the heat break thermal transition zone, but not into the typical melt zone within the heater block. As a result, pumping of filament retractions will cause ozze to extrude upwards into the 2.2 mm bore of the transition zone where it cools and solidifies, forming a 2.2 mm plug that can no longer be pushed into the 2.0 mm bore and subsequent melt zone.
Filament unloads following a jam showing a very typical 2.2 mm stub are indicative of the issue.
Filament stubs:
E3D heat break:
Prusa mod:
RE: Replacing the Heat Break
As for procedure to replacing the heat break: please, save yourself a LOT of grief, and read these before taking things apart and reassembling. Trust me, you'll thank yourself for understanding the procedure and following it to the letter ... especially keeping nozzle to heater block spacing correct and observing torque temperatures.
https://wiki.e3d-online.com/E3D-v6_Assembly
ps:
The heat sink will come loose at room temperature.
The nozzle-heat break connection is a different story: it "might" come loose, but might not; people often bend the heat break or break the nozzle trying. It's best done at 280c.
RE: Replacing the Heat Break
Thank you @groc426 and @tim-m30 for the information.
For my CAD drawings I have used drawings from E3D-online and I therefore did not know that Prusa had another heat-break.
But you have now convinced me of the problem with Prusa's heat-break.
I have not experienced any problems with this, but if I ever need to change heat-break then it will be a V6 from the E3D.
Bear MK3 with Bondtech extruder
RE: Replacing the Heat Break
Hi all... I'm seriously thinking into changing for the heat break for the E3D original design.
Still, I have two questions, I would like your feedback:
1) E3D also offers a titanium heat break. Will it be an improvement? Is it worth it?
2) after this "mod" do you keep using the prusa PTFE tube?
MK3 updated to MK3S / mainly textured steel sheet (also have a smooth one) / PLA and PETG
RE: Replacing the Heat Break
Titanium is supposed to work better as Ti doesn't conduct heat as well as SS. It is a direct replacement, though you will need to add heat sink grease to the heat sink threads for assembly. And follow the E3D assembly instructions to the letter.