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[Jules]

Shoot! Just a handy tip....when you break down your hot end to unclog it - remember to put the little black sleeve back on. (Could not figure out why all my temps had changed so dramatically, until i sat on the freaking thing. My poor little hot end is freezing its buns off. )

On another note - if you do take your fan guards off - prepare to rework your temps. The fan cools the nozzle and the bed a lot more without the guards, you'll probably need to increase the temps for both by a few degrees. (Complete common sense, i know, but i've got nothing else to do while waiting for this print to finish, so I can put the little sleeve back on. )

[insta]

I have a chronic shortage of those sleeves ... whenever I fail a print, I fail it in a BIG way and usually encase the hotend in a few ounces of plastic. The hotends usually survive (usually...) but the sleeves never do. I need to find what that stuff is at McMaster and just order a small spool of it.

[CCVirginia]

Since you guys are so great at posting instructions, it would be useful to have one on "breaking down a hot end" - something I have avoided thus far.

Questions that come to mind:
* Do you unscrew the nozzle hot or cold? If cold, wouldn't internal plastic make it hard? If hot - ouch!
* The nozzle fits a wrench, but there is nothing on the other side - how do you keep from breaking things? What do you hold onto?
* What parts (like the sleeve) will be needed to put it back together.
* Any general disassembly/assembly hints?
* Any special tools?
* Is it the same for a V3b and V4?

Thanks!

[thunderbt3]

V3B instructions:
Just reverse the assembly instructions
http://makergear.wikidot.com/m2-hotend-assembly

V4 instructions:
My thermistor was just sitting in there and the ceramic heater is held in by a grub screw. I used a 13mm? box wrench on the heater block and 11mm? box wrench on the nozzle. Crescent wrenches will work just fine. The stainless steel tapered "heat zone" part of the nozzle is pressed into the heater block, or least it seems pressed in. With a little heat on the heater block, it will come right off.

[insta]

For the V4...

My process (not the right one, just mine) is usually:

* Collect tools: 14mm wrench, 11mm wrench, tweezers, 618 Nylon or eSUN cleaner filament, blowtorch
* Cool the hotend to room temperature
* Pull the black sleeve off with tweezers
* Loosen the screw that holds the hotend in place, but don't remove the hotend
* (optional) touch the brass tip of the hotend with the torch for like 2 seconds, just enough for it to feel warm to the touch
* Place the 14mm wrench on the body of the hotend
* Place the 11mm wrench on the nozzle of the hotend
* Loosen the nozzle, using the 14mm wrench to ensure the hotend does not move
* Fully remove the nozzle, set aside, leave the hotend core in the machine
* Tighten the hotend mount screw
* Heat the hotend to 220C, purge with cleaner filament or Nylon -- this will be amazingly nasty and gross with all the crap that comes out
* Blowtorch the everloving piss out of the brass nozzle, until its glowing a dull red, let cool to room temperature on its own
* Loosen the hotend screw again
* Reassemble the hotend
* Reheat the hotend to 220C
* Give a final tweak on the nozzle ... don't gorilla-fist it, just a little "erk" on the nozzle
* Home Z, let the hotend bump back into place, tighten the screw

[Jules]

Since you guys are so great at posting instructions, it would be useful to have one on "breaking down a hot end" - something I have avoided thus far.

Questions that come to mind:
* Do you unscrew the nozzle hot or cold? If cold, wouldn't internal plastic make it hard? If hot - ouch!
* The nozzle fits a wrench, but there is nothing on the other side - how do you keep from breaking things? What do you hold onto?
* What parts (like the sleeve) will be needed to put it back together.
* Any general disassembly/assembly hints?
* Any special tools?
* Is it the same for a V3b and V4?

Thanks!

ROFL! I'm still laughing at insta's description - You should not need to break down the hotend unless you are bouncing back and forth between PETG and PLA frequently without cleaning in between - but I did finally manage to get a bit of smut in there and the cleaning filament was quite jammed.

The V4 is very simple to break down, and if you don't have a death wish - you can actually wait until it cools down to take it apart. (These guys are muy macho hombres, I tell ya! ) And here's the plus to cooling it off first- if you wait until it's cool, when you pull the nozzle off, all the crap in the barrel just slides right out attached to the nozzle. (Should have taken a picture of that, it was cool.)
It's like the ultimate cold-pull.

So what i did (V4):

Retracted the filament and made sure it was clear of the hotend. Cut the power.
Let the nozzle cool.
Removed the hotend. (Probably not necessary, but it was my first time and i wanted to see what was going on.)
Removed the little black cloth cover thing.
Took two pairs of adjustable wrenches and unscrewed the nozzle. Nothing more than a snug fit - the barrel comes all the way down to touch metal on the nozzle. It is not filled with plastic around the threads.
Took off the nozzle, and all the (not yet melted) filament in the barrel came out - still attached to the nozzle.
That was handy, because it gave a nice long handle that i could grab with the pliers and just sloooowly twist against the top rim of the nozzle. After a bit, the plug (with little bits of carbonized smut) popped right out of the nozzle.
Still some stuff left in there cooked to the walls, but it wasn't interfering with extrusion so i just put it back on. (You can blow torch it or dissolve the smut if you are so inclined - i just didn't have time to mess with it this time.)
Reset the Z and i was off and running again.

Pic of the plug that came out - that tube is hollow, and it's the residue left on the walls of the barrel after you retract. (Caught most of the crap that was left on the walls, too.) The crimped spot is where i caught it with the tweezer nose pliers and pulled it out of the nozzle.

Eeeew! All that carbonized crud on the tip!

Plug.jpg (187.9 KiB) Viewed 8421 times

[insta]

I sorta want to try printing with just the hole from the V4, no nozzle on it. E3D Volcano? childs play

[Jules]

I sorta want to try printing with just the hole from the V4, no nozzle on it. E3D Volcano? childs play

Yep! Scary!