A New Hot-end Makes all the Difference...

[The Hat]

Ok, the hot-end on my CR-10 was constantly getting clogged up and blocking every 15 minutes or so, I didn’t have a clue till @Nija mentioned that if you exceed a certain temperature in the head the Teflon lining can get damaged and can cause the filament to become trapped.

I went about pulling everything apart, but I couldn’t get the throat, (it’s also called a heat brake) separated from the heat block and it snapped, with half still stuck in the heat block, when I examined the throat later the Teflon lining was crumpled and blackened, and I reckoned that was the cause of my problem.


I purchased two new hot-ends form AliExpress along with a few other pieces like three new point 4 brass nozzles, several extra heat brakes (throats) , which were the wrong type, but I’ll get the right one’s next time, I wanted the heat brake with the Teflon lining.

Here are the remains of my old hot-end, I salvaged the thermistor and cartridge heater out of the heat block, so I could use them in the new upgraded one, I also got some new needles.

When you get a new Hot-end it usually comes in one piece, but you must separate all the parts before you can start to assemble them properly, this give you a chance to see all the bits and pieces up close.


You start by screwing in the brass nozzle into the head block tight first, but back it off a quarter turn, then put in the thermistor and screw that in tight, but don’t crush the wire, follow that up with the cartridge heater, centre it in the heat block and tighten.

Next you can screw the throat into the heat block, but first it’s better to have a heat sealing paste on the threads to help it seat properly, and while you’re at it also helps to put a little paste on the head of the brass nozzle, I forgot to mention that earlier, sorry.

You can now tighten the brass nozzle into the heat block bot not to tight, because you may need to remove that if it ever becomes blocked, the last thing to add is the heat sink, you can tighten that down by hand but don’t forget to lock it in place with the tiny screw on the side.

The Pneumatic connector can be placed on the top and tightened by hand also, now all you got to do is attach it to the printer with the two screws that held on the old hot-end, and fix the cooling fans in place.


It’s best to heat the hot-end up to 190 c for a few minutes and then hand feed a piece of filament through the top and check that the filament is passing through the head and exiting the nozzle smoothly it should come out of the nozzles with a wiggle and then go straight, then pull out the test filament and in shove the PTFE feeding tube into the top and you’re ready to start printing...

My printer hasn’t stopped since...

 

[Nifty]

Wow, fantastic write-up @The Hat !!

I've seen a bunch of similar situations... PTFE / Bowden tube melting / causing problems, throat / snapping in half, etc. This is part of the many reasons whey I don't want to mess with hotter temps.

Some people are saying that the capricorn bowden tubes are a good upgrade since they have better tolerances, are smoother, and can take higher temps: https://www.captubes.com/

This is the hot-end you're using, right? https://www.aliexpress.com/item/Ful...32825427805.html?spm=a2g0s.9042311.0.0.wjqf8n

Again, thanks for this fantastic post!

 

[Redbrickman]

Great write up The Hat. Wil be useful in the future when I need to change it.

 

[Nifty]

In the same vein as my fear of swapping nozzles, I've been interested in swapping out one my CR10 hotend with one of the 3 SUPER cheap ones from China, but again, I don't want to mess with something that's working.

I guess I don't really have a real reason to swap out the hot end... more curiosity than anything.

I wish there were some good videos of people swapping out these hot-ends for these Chinese ones. I'm having a hard time wrapping my head around what all I need to do besides screwing it into place... mostly, what to do with the thermisor and heater cartridge wires. Can I just use existing? Do I need to run them all the way to the CPU/board? etc.

 

[The Hat]

what to do with the thermisor and heater cartridge wires. Can I just use existing? Do I need to run them all the way to the CPU/board? etc.

If I need to swap any or all the hot-end pieces, I usually like to keep and reuse the heater cartridge and thermistor, my last change was to install a heat brake (Throat) without the Teflon liner. (It’s easier to replace the whole hot-end in one go), I got a couple of them spare..

Most of the time both the heat cartridge and thermistor don’t need to be replaced, but if they do I locate each of the wires and cut them just about 10” from the Fang.

It’s a straight forward job using inline crimps or just use solder, which ever is most convenient, I’ve had to replace both units a couple of times due to some problems, and if you can fit the Fang onto your printer then replace the hot-end is just one step more, just don’t overtighten the screw holding the thermistor wire (I did), Ops...

The more you change on the printer the more knowledgeable and comfortable you get using the printer, because there’s nothing you haven’t done before, so everything becomes easy-peasy...

 

[Nifty]

Brilliant, thanks!

I've got 3 "spare" hotends, two of the clones of the one that's on the CR-10 (is this an MK8 hotend? J-head hotend? I don't understand all the naming conventions?) and a e3d V6 clone.

One of the CR-10 hotends has the same coloring and insulation as the one on my CR10, the other doesn't. Not sure if there are more differences between these two or not?

 

[Nifty]

Also, I noticed that the orientation of the nozzle and headsink / throat were different on the ones I received vs. the one on the CR10. I assume these can be switched / flipped to match the orientation (so the wires come out the right side, etc.) without any issues?

 

[The Hat]

@Nifty, OK the other hot-end you have in the bag (Top) as far as I can tell is a V6 head hot-end extruder with the remote Bowden (Long Distance).

Here is a photo of both heads... with the short on the left.
and here is the heat sink with a proper gap between it and the heat block...

The silver coloured one looks ok to use, but I wouldn’t use the red coloured one till you extend the heat sink a bit further away from the heat block.

The orientation can be altered if necessary by twisting it by hand using brute force or loosen the small grub screw on the front of the heat sink, also you can have the wires coming out whichever side suits the hot-end your using, and cable ties will do the rest...


Have fun...

O’ you may also need one of these....
Ops...

 

[Nifty]

Thanks man!

OK the other hot-end you have in the bag (Top) as far as I can tell is a V6 head hot-end extruder with the remote Bowden (Long Distance).

Correct! It was just too cheap not to pick one up "just in case"

O’ you may also need one of these

I just ordered a few silicone socks from ebay. I wasn't 100% sure if I should get the MK9 or MK10 one... but at $1.55 each, I figured I could get both

Hopefully those will work fine on their own and I won't have to deal with tapes, insulation, etc.

 

[The Hat]

I just ordered a few silicone socks from ebay. I wasn't 100% sure if I should get the MK9 or MK10 one...

These silicone socks don’t fit the V5 or V6 heads properly, so you’ll have to apply a little work around to hold them on, I used steel spring wire (Unravelled) to hold my sock on successfully, otherwise they have a tendency to slip off when things start to get hot...

Looking from the back, the wire is visible ..