<p>As suggested in comments, I've installed Luke Hatfield's captive PTFE tube fix using high temperature Capricorn PTFE tube inside the heat break, and this seems to have solved the problem, while accomplishing the main thing I wanted an all metal hot end for: allowing higher print temperatures for filaments that require it.</p>
<p>In my case, I had to modify the classic procedure a bit; careful measurement of my heat sink required printing a custom &quot;washer&quot; with top end diameter of 8 mm, bottom (against the heat break) diameter of 5 mm, 4 mm taper length, 1 mm thick non-tapered top extension (so the coupler could compress the washer into place); I drafted a 2.25 mm bore (after an initial prototype at 2.1 mm wouldn't pass filament with marks from the extruder teeth; there's probably some shrinkage in the printing process) and an entry cone of 3.125 mm diameter, tapering to bore diameter after the first 3 mm.</p>
<p>I cut a piece of Capricorn PTFE tube 1 mm longer than the heat break; assembled heat break to heat sink (to ensure it was bottomed against the shoulder in the bore), then screwed heat break into the heat block to set depth, ensuring that the nozzle would tighten against the heat break before bottoming the hex against the heat block.  Hot tightening the nozzle, followed by tightening the coupler, gave about 3% compression of the captive Capricorn tube, ensuring a good seal against the nozzle.</p>
<p>I kept the stock, translucent PTFE for the Bowden tube, so I can see the filament (at least as a shadow) when I load it, but where it matters, I now have captive, compression sealed PTFE that's rated up to 300 °C -- and this has so far worked perfectly for a number of prints.</p>

CC BY-SA 4.0
2021-07-26T11:26:21.853Z
2021-07-26T11:26:21.853Z
Zeiss Ikon
<p>I was having heat creep related hot end clogs leading to skipped layers or plain old air printing (with extruder stepper skipping).  Since I'd just received the all metal hot end I ordered a while back (Chinese knock-off, verified 2 mm heat break bore), I installed that and tried a print without changing settings.</p>
<p>Amazon Basics PLA, 200 °C at 0.4 mm nozzle, 50 mm/s (which gives walls and first layer at 25 mm/s), and 30% tri-hex infill -- and instead of clogging an hour an a half into the print, the new setup clogged after only about half an hour.</p>
<p>There is little retraction in this part -- every layer is continuous (that is, there are no travels between sections, only between infill lines and after layer end, it's a simple extruded shape from the first layer to the last), so I wouldn't expect excessive retraction to be a major issue.</p>
<p>Is this likely to be due to printing with the same settings I had for the original hot end?  If so, what should I change (retraction, obviously, but temperature, print speed, etc.?).</p>
<p>EDIT: Reinstalling the previous (stock type) hot end after clearing filament material from the heat break has restored normal-seeming operation, at least when starting a print from cold.  Parts are on the way to apply the <a href="https://www.thingiverse.com/thing:3203831" rel="nofollow noreferrer">PTFE fix</a>.</p>

CC BY-SA 4.0
2021-07-19T13:45:11.937Z
Extruder cooling fan isn't powerful enough? Have you changed your hotend fan?
FrontENG
CC BY-SA 4.0
2021-07-19T13:46:37.943Z
@FrontENG Still running the stock fan for both heat sink and part cooling.
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T14:02:06.313Z
This kind of all metal hotend is not recommended for just PLA.It's not an "upgrade".The metal throat tube actually make it easier for heat to creep up unless you install a more powerful fan. 0scar explains this in his answer https://3dprinting.stackexchange.com/a/11979/19888
FrontENG
CC BY-SA 4.0
2021-07-19T14:05:43.283Z
And did you try the [PTFE fix for creality MK8 hotend](https://www.thingiverse.com/thing:3203831)?There could be a gap between nozzle and ptfe tube which increases drag and causes "clog" looks like heatcreep
FrontENG
CC BY-SA 4.0
2021-07-19T14:26:10.600Z
@FrontENG Why does everyone assume that someone who's had a printer for two months has read every word on every source about it?  " the PTFE fix" is what?  I'm pretty confident that I didn't have a gap on the old hot end; I installed the Bowden tube cold, and got a pretty solid bottom out when I did.  The tube was cut with a tubing cutter, so I'm confident the end is square.
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T15:58:35.443Z
@FrontENG Okay, that's the *captive, high temperature* PTFE mod, with spacer under the coupler fitting.  Nope, haven't tried it.  Sounds like you're saying I should.
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T18:31:20.867Z
All metal hot ends conduct more heat to the filament in the heatbreak.  Thus, it's easier to get heat creep.
Perry Webb
CC BY-SA 4.0
2021-07-19T18:35:13.140Z
@PerryWebb Hence why the heat break is made of titanium or stainless (both relatively poor heat conductors), and often has a reduced diameter neck between the heat block and heat sink, to control this heat transfer.  Apparently, it's not enough.  Or the tube should be chromed inside or coated with boron nitride or similar to prevent adhesion...
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T18:40:06.113Z
Yes, but if the heatbreak is lined with PTFE or has the PTFE bowden tube go all the way to the nozzle, the filament is even better isolated.
Perry Webb
CC BY-SA 4.0
2021-07-19T18:44:17.463Z
Maybe replace the PTFE in the heatbreak with high-fire glazed ceramic.
Perry Webb
CC BY-SA 4.0
2021-07-19T18:44:19.867Z
But then we're limited by the breakdown temperature of PTFE.  I've ordered a Capricorn tube kit, and I'll find or make a spacer to recreate the "PTFE fix" in one of my lined hot ends, then clean up the all metal one and save it for high temperature.  At least I didn't pay name brand price...
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T18:45:42.800Z
@PerryWebb "Maybe replace the PTFE in the heatbreak with high-fire glazed ceramic."  Hmm.  Porcelain tube, 2mm ID, 4 mm OD, high glaze...  Sounds expensive...
Zeiss Ikon
CC BY-SA 4.0
2021-07-19T18:54:26.803Z
Change the heaterblock and heatsink to copper, then you would have an extruder capable of very high temperature.  But, too expensive unless you really need it for the material being printed.   Back from chasing the rabbit, even a poor thermal conducting metal conducts much more than PTFE.
Perry Webb
CC BY-SA 4.0
2021-07-19T18:56:47.883Z
Maybe a Pyrex or quartz tube would work and be less expensive.
Perry Webb
CC BY-SA 4.0
2021-07-20T14:39:32.247Z
Print faster, increase cooling. What is your speed?
FarO
CC BY-SA 4.0
2021-07-20T14:41:36.050Z
No settings were changed (in fact, I used a .gcode file already on my microSD for the parts I was printing); full speed at Cura default 50 mm/s, walls and first layer at 25 mm/s.  Layer height 0.28 mm, 30% tri-hex infill.
Zeiss Ikon
CC BY-SA 4.0
2021-07-22T14:54:31.303Z
Anyway the Ender 3 should not have heat creep in its standard configuration. Yes all-metal may worsen it, but if you have it with the stock hotend, something else may be wrong. I had heat creep with PLA in the past, I solved it by adding a fan to cool the filament before it enters the extruder+hotend, however it was direct drive and easy to do. Try to cool the bowden tube near the hotend and see... maybe the air is too warm
FarO
CC BY-SA 4.0
2021-07-22T15:46:47.253Z
@FarO As others have suggested, this might be due to the Bowden tube backing up under pressure.  I haven't had a clog since reinstalling the stock type hot end, and I'll be installing the "PTFE fix" (captive high temp PTFE inside the heat break) this weekend.
Zeiss Ikon
<creality-ender-3><all-metal-hotend><heat-creep>
Ender 3 Upgraded to All Metal Hot End -- Heat Creep?
Zeiss Ikon
# Ender 3 Upgraded to All Metal Hot End -- Heat Creep?

(Asked by: username_0 on 2021-07-19)

I was having heat creep related hot end clogs leading to skipped layers or plain old air printing (with extruder stepper skipping). Since I'd just received the all metal hot end I ordered a while back (Chinese knock-off, verified 2 mm heat break bore), I installed that and tried a print without changing settings.

Amazon Basics PLA, 200 °C at 0.4 mm nozzle, 50 mm/s (which gives walls and first layer at 25 mm/s), and 30% tri-hex infill -- and instead of clogging an hour an a half into the print, the new setup clogged after only about half an hour.

There is little retraction in this part -- every layer is continuous (that is, there are no travels between sections, only between infill lines and after layer end, it's a simple extruded shape from the first layer to the last), so I wouldn't expect excessive retraction to be a major issue.

Is this likely to be due to printing with the same settings I had for the original hot end? If so, what should I change (retraction, obviously, but temperature, print speed, etc.?).

EDIT: Reinstalling the previous (stock type) hot end after clearing filament material from the heat break has restored normal-seeming operation, at least when starting a print from cold. Parts are on the way to apply the [PTFE fix](https://www.thingiverse.com/thing:3203831).

**Tags:** creality-ender-3, all-metal-hotend, heat-creep

> **Comments:**
> **username_1**: Extruder cooling fan isn't powerful enough? Have you changed your hotend fan?  
> **username_0**: @username_1 Still running the stock fan for both heat sink and part cooling.  
> **username_1**: This kind of all metal hotend is not recommended for just PLA.It's not an "upgrade".The metal throat tube actually make it easier for heat to creep up unless you install a more powerful fan. 0scar explains this in his answer https://3dprinting.stackexchange.com/a/11979/19888  
> **username_1**: And did you try the [PTFE fix for creality MK8 hotend](https://www.thingiverse.com/thing:3203831)?There could be a gap between nozzle and ptfe tube which increases drag and causes "clog" looks like heatcreep  
> **username_0**: @username_1 Why does everyone assume that someone who's had a printer for two months has read every word on every source about it?  " the PTFE fix" is what?  I'm pretty confident that I didn't have a gap on the old hot end; I installed the Bowden tube cold, and got a pretty solid bottom out when I did.  The tube was cut with a tubing cutter, so I'm confident the end is square.  
> **username_0**: @username_1 Okay, that's the *captive, high temperature* PTFE mod, with spacer under the coupler fitting.  Nope, haven't tried it.  Sounds like you're saying I should.  
> **username_2**: All metal hot ends conduct more heat to the filament in the heatbreak.  Thus, it's easier to get heat creep.  
> **username_0**: @username_2 Hence why the heat break is made of titanium or stainless (both relatively poor heat conductors), and often has a reduced diameter neck between the heat block and heat sink, to control this heat transfer.  Apparently, it's not enough.  Or the tube should be chromed inside or coated with boron nitride or similar to prevent adhesion...  
> **username_2**: Yes, but if the heatbreak is lined with PTFE or has the PTFE bowden tube go all the way to the nozzle, the filament is even better isolated.  
> **username_2**: Maybe replace the PTFE in the heatbreak with high-fire glazed ceramic.  
> **username_0**: But then we're limited by the breakdown temperature of PTFE.  I've ordered a Capricorn tube kit, and I'll find or make a spacer to recreate the "PTFE fix" in one of my lined hot ends, then clean up the all metal one and save it for high temperature.  At least I didn't pay name brand price...  
> **username_0**: @username_2 "Maybe replace the PTFE in the heatbreak with high-fire glazed ceramic."  Hmm.  Porcelain tube, 2mm ID, 4 mm OD, high glaze...  Sounds expensive...  
> **username_2**: Change the heaterblock and heatsink to copper, then you would have an extruder capable of very high temperature.  But, too expensive unless you really need it for the material being printed.   Back from chasing the rabbit, even a poor thermal conducting metal conducts much more than PTFE.  
> **username_2**: Maybe a Pyrex or quartz tube would work and be less expensive.  
> **username_3**: Print faster, increase cooling. What is your speed?  
> **username_0**: No settings were changed (in fact, I used a .gcode file already on my microSD for the parts I was printing); full speed at Cura default 50 mm/s, walls and first layer at 25 mm/s.  Layer height 0.28 mm, 30% tri-hex infill.  
> **username_3**: Anyway the Ender 3 should not have heat creep in its standard configuration. Yes all-metal may worsen it, but if you have it with the stock hotend, something else may be wrong. I had heat creep with PLA in the past, I solved it by adding a fan to cool the filament before it enters the extruder+hotend, however it was direct drive and easy to do. Try to cool the bowden tube near the hotend and see... maybe the air is too warm  
> **username_0**: @username_3 As others have suggested, this might be due to the Bowden tube backing up under pressure.  I haven't had a clog since reinstalling the stock type hot end, and I'll be installing the "PTFE fix" (captive high temp PTFE inside the heat break) this weekend.  

---

## 1 answers

### Answer by username_0 on 2021-07-26. Score: 1 | Accepted answer

As suggested in comments, I've installed Luke Hatfield's captive PTFE tube fix using high temperature Capricorn PTFE tube inside the heat break, and this seems to have solved the problem, while accomplishing the main thing I wanted an all metal hot end for: allowing higher print temperatures for filaments that require it.

In my case, I had to modify the classic procedure a bit; careful measurement of my heat sink required printing a custom "washer" with top end diameter of 8 mm, bottom (against the heat break) diameter of 5 mm, 4 mm taper length, 1 mm thick non-tapered top extension (so the coupler could compress the washer into place); I drafted a 2.25 mm bore (after an initial prototype at 2.1 mm wouldn't pass filament with marks from the extruder teeth; there's probably some shrinkage in the printing process) and an entry cone of 3.125 mm diameter, tapering to bore diameter after the first 3 mm.

I cut a piece of Capricorn PTFE tube 1 mm longer than the heat break; assembled heat break to heat sink (to ensure it was bottomed against the shoulder in the bore), then screwed heat break into the heat block to set depth, ensuring that the nozzle would tighten against the heat break before bottoming the hex against the heat block. Hot tightening the nozzle, followed by tightening the coupler, gave about 3% compression of the captive Capricorn tube, ensuring a good seal against the nozzle.

I kept the stock, translucent PTFE for the Bowden tube, so I can see the filament (at least as a shadow) when I load it, but where it matters, I now have captive, compression sealed PTFE that's rated up to 300 °C -- and this has so far worked perfectly for a number of prints.


---

