Struggling with heat creep on Mk3s
I recently upgraded my Mk3 to Mk3s, and since upgrading I've been really struggling with heat creep. Prints jamming after just a few layers and having a large blob at the end of the filament, when removed after the jam.
The fan that is blowing on the heat break is installed correctly (the label is on the inside), and watching it spin, it is spinning in the correct direction to blow air over the heat sink. However when I put my hand near the fan, I feel air blowing in what feels like the opposite direction, away from the heat sink. Putting my hand on the opposite side from the heat sink, I feel little, or no air movement.
It is almost as if the air is being blown in, and bounces off the heat sync and comes back out the same side.
I had damaged my hot end a year or so ago, so replaced/upgraded it with an E3d V6 Gold hot end. I don't know if there is a difference in the heat sink size/density that might be causing this, but it worked just fine for months until I did the Mk3s upgrade. I did try reversing the fan, so the label side was out, and it felt like more air was being pushed away from the heat sink, but the heat creep was worse.
When I reversed the fan there was some filament stuck in there from a previous failed print. That could have caused the fan not to be spinning optimally, but I think I have it all cleaned out.
I'm just sort of searching for ideas where to go next. I'm contemplating replacing the Noctua 40x10mm fan, as perhaps I've damaged it somehow. I'm also contemplating replacing it with a 40x20mm fan wondering if I need the extra pressure and or volume of air would help. I've contemplated removing much of the Mk3s shroud around the heat sink, and replacing it with the fan/shroud that came with the E3d gold, but I'd rather not go that far. I've contemplating getting 2 fans and trying in a push/pull configuration.
Right now the Batman logo on the SD card is the only part I can print with any reliability with any sort of filament. Anything else that is larger, taller, or has more retractions is just causing jam after jam.
I've gone through some of the other heat creep threads, adjusted the bondtech gears, and have them pretty loose. It just seems I can't get adequate cooling to heat sink since upgrading to the Mk3s
RE: Struggling with heat creep on Mk3s
Now I want this: https://www.amazon.com/Genuine-E3D-Gold-HotEnd-V6-175-GOLD-12V/dp/B076BTL7H5#feature-bullets-btf
There was a firmware version on the 15th. Do you have that?
Reading the hot end description reveals the below. Have you lowered your nozzle temp?
Heater Block
We’ve switched the aluminium heater block for a plated copper-alloy block, again increasing heat transfer to the filament and reducing the chance of filament goo sticking to it. This reduces the need for a sock, so that you can show off the shiny engraving.
RE: Struggling with heat creep on Mk3s
Now I want this: https://www.amazon.com/Genuine-E3D-Gold-HotEnd-V6-175-GOLD-12V/dp/B076BTL7H5#feature-bullets-btf
If you're going to invest the money, at least get yourself the 24V version for the Mk3/Mk3s. 😉
RE: Struggling with heat creep on Mk3s
I recently upgraded my Mk3 to Mk3s, and since upgrading I've been really struggling with heat creep. Prints jamming after just a few layers and having a large blob at the end of the filament, when removed after the jam.
The fan that is blowing on the heat break is installed correctly (the label is on the inside), and watching it spin, it is spinning in the correct direction to blow air over the heat sink. However when I put my hand near the fan, I feel air blowing in what feels like the opposite direction, away from the heat sink. Putting my hand on the opposite side from the heat sink, I feel little, or no air movement.
It is almost as if the air is being blown in, and bounces off the heat sync and comes back out the same side.
That's what axial fans do, when they're struggling with too much air flow resistance. The flow in the fan turns into a radial flow instead and the fan will start blowing out and back to the sides instead of forward.
I had damaged my hot end a year or so ago, so replaced/upgraded it with an E3d V6 Gold hot end. I don't know if there is a difference in the heat sink size/density that might be causing this, but it worked just fine for months until I did the Mk3s upgrade.
The V6 Gold should be dimensionally identical to the normal V6. Just gold anodized and with the copper block.
I did try reversing the fan, so the label side was out, and it felt like more air was being pushed away from the heat sink, but the heat creep was worse.
Yes, these fans are even lousier at suction pressure than they're in a push configuration.
When I reversed the fan there was some filament stuck in there from a previous failed print. That could have caused the fan not to be spinning optimally, but I think I have it all cleaned out.
I'm just sort of searching for ideas where to go next. I'm contemplating replacing the Noctua 40x10mm fan, as perhaps I've damaged it somehow. I'm also contemplating replacing it with a 40x20mm fan wondering if I need the extra pressure and or volume of air would help.
The 40x20 fans will not fit, they will hit the left X end and homing will be off. For a 40x20 you'd need to print an angled adapter, and then most of the advantages are gone anyway.
I've contemplated removing much of the Mk3s shroud around the heat sink, and replacing it with the fan/shroud that came with the E3d gold, but I'd rather not go that far. I've contemplating getting 2 fans and trying in a push/pull configuration.
The fan is used as a structural part on the Mk3 and Mk3s extruders, it holds the extruder together. So I think that if you cut off most of the extruder, the whole thing would become rather flimsy and you'd lose rigidity and it'd show in prints.
Right now the Batman logo on the SD card is the only part I can print with any reliability with any sort of filament. Anything else that is larger, taller, or has more retractions is just causing jam after jam.
I've gone through some of the other heat creep threads, adjusted the bondtech gears, and have them pretty loose. It just seems I can't get adequate cooling to heat sink since upgrading to the Mk3s
Can you check what the heatsink temperature is after a longer print? Is it close to ambient air, warm or hot to the touch?
Did you assemble the Gold yourself, or did you get the pre-assembled one? Any chance the heatsink is close to the heater block without enough separation across the heatbreak or perhaps even touching it?
RE: Struggling with heat creep on Mk3s
So, to follow up on this. I disassembled the hot and, and it looked like during my upgrade to the mk3s, I must have loosened the heat sink from the heat break. It wasn't loosened much, but enough that there was probably air between the now dried bits of thermal compound on each side.
I cleaned everything out, applied new thermal compound, made sure things were good and tight, and now it seems to be working well again. Thanks for guidance on where to look.