Notifications
Clear all

Hot end lifespan  

  RSS
bowtie6
(@bowtie6)
Eminent Member
Hot end lifespan

Hello -

My MK4 -> MK4S converted printer has been working very well.  It took a little time to dial in a few things but overall I am very pleased with the results.  Today, I powered up and immediately had hot end issues.  After running calibration many times, I kept getting the hot end temp failure error.  I also tried the option to bring the printer up to temp, selected PLA or PETG and either way it would only make it up to a certain temp...  Then it would start falling back.

At first, I thought the firmware was at fault so I dialed it back a release and that did not help matters.  I have a brand new spare hot end, installed it and ran the calibration again.  This time, all tests completed with the green checkmark and all is good.  

I bought my printer about a year ago.  When I upgraded it to MK4S, I took extra care not to pinch any wires when it came installing the new fan assembly.  So I have a few questions...

  • How long does a hot end last?  I realize these are consumable parts that won't last forever.  Has anyone replaced their hot end assembly?
  • What can be done with the 'bad' one?  Toss it, or can I replace the parts on it?  I noticed there are three small hex screws - I take it that is what holds the heater element in place.  Is this something that can be replaced?
  • Finally, are there any tricks to make these hot ends last longer?    

Thanks for any info...  

Posted : 05/12/2024 11:43 pm
FoxRun3D
(@foxrun3d)
Famed Member
RE: Hot end lifespan

I have machines that have run for years and never needed any hotend components replaced. I don't consider the hotend a "consumable". But heater elements and thermistors do break. You can check out the Prusa Knowledgeable articles for how to replace them. It's pretty easy.

https://help.prusa3d.com/guide/how-to-replace-a-hotend-thermistor-mk4-mk3-9_635632

https://help.prusa3d.com/guide/how-to-replace-a-hotend-heater-mk4-mk3-9_634849

Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...

Posted : 06/12/2024 12:38 am
bowtie6 liked
bowtie6
(@bowtie6)
Eminent Member
Topic starter answered:
RE: Hot end lifespan

Thank you @fuchsr for the links.  After reading the links you gave me, we have this:

It looks like the thermistor might have had an issue.  I expected that to come out like the heater did in one piece, but it looks like the ceramic-like material separated.  Perhaps that lead to inaccurate readings?  At any rate, I have ordered a new thermistor and heater and will be putting this together when they come.

One final observation:  when I put all this back together it will be assembled with some high-temp copper anti-seize.  This should help those threads - you don't want to have any of this galling...

Posted : 06/12/2024 9:10 pm
Share: