MakerGear Forum

Hi all.

Quick question:
Is the v4 hot end all metal?

my nozzle (and borderline entire hot end) is very clogged to the point I may need to do something drastic. I can barely push pla through it.
Maybe it is easier to declog it with ABS ? cold pull method?

(I generally print PLA, had a few early signs of string pulling towards one side but not more than that. I printed a bit of Pet(g) then back to PLA. I let quite a bi tof filaments run through at higher temps without issues, but now, it just stopped extruding and managed only to push through small, tiny strings, so something big has clogged it.

I figured if this does not work, the clogging seems to go half a cm up the hot end, I may need to bring out the blowtorch....

Here is what I would do, and actually do when this happens.

1) Remove the hotend from the printer. There is a very good chance of snapping the neck/barrel off the hotend if you do not. (Ask me how I know. )
2) Remove the nozzle.
3) Connect the hotend wires and turn the heat on, and you should get some of the clog to start to drip out if its in the barrel. Most of the time its in the nozzle.

I wouldn't blowtorch the whole thing, there is a PTFE tube inside that will burn/melt and make things worse. You can blowtorch the nozzle after you remove it in step 2.

Thanks, that's why I asked if it was all metal...

I thought there might be a PTFE tube inside the but wasn't sure... better ask first, I thought.

and yes... I know .. I've bent one v4 hot end when doing ... something.

I've clear snapped two of them so far. I promised myself to never do that again...lol...

I've only snapped one ... so far.

Oh... and I start to think there is something wrong with my filament, at least this roll.
I haven't had a clogged nozzle in a year and a half.

It clogged on me bad yesterday. I swapped it out for a brand new v4 nozzle I had lying about, and guess what.. second print in (same filament roll as before), THIS one clogs on me as well!

The roll was taken out of its packaging 2 days ago, plastic wrapped with silica gel, so I am starting to suspect something is fishy with the roll...

Filament is honestly the biggest variable in 3d printing. I know that is quite obvious, but sometimes, unrealized.

I try for the most part to use the same brand of filament if possible. Most of the worst clogs have happened from using a random filament, where the temps were hard to get right. Some filament, even just regular PLA is just hard to print, settings need to be worked on so much to get it good, that honestly, I end up just sealing them back up and putting them in a pile.

And there is always the possibility of a bad roll.

You should always run a cleaning filament through the hotend which switching types of filament.

You be surprised on how much old filament can be left in the nozzle/hotend (say stuck to the sides) even when just switching colors. I was running black PLA and then switched to blue and ran a 12 hour job with out any issues. I started a new job the next day with the same blue loaded and the first layer had signs of black in it.

I bet the same thing happened in your case... but worse because you ran PLA then changed to PETG and with the higher temp and PLA in the nozzle finally cooked off the sides and baked solid and probably clogged the nozzle.

Even something as simple as dust can clog a nozzle you should also run a dust wiper. (Simple solution).

Overall... clogs can just happen no matter what. On one of my presses I run nothing but black abs always using the same brand and it still occasionally clogs. One tell tale sign that a partial clog is start is when purging filament you can see it start to curve out of the nozzle. (it doesn't always mean it going to clog but its a good sign something is starting.) I routinely swap out nozzles and blow touch them before full clogs can happen.

-Steve

the Teflon lining makes things much less clog prone these days. many of you guys missed out on the old v3a and v3b days. you get about 5-10 plastic changes before that brass barrel was so tight you couldn't get filament through it anymore.

jimc wrote:the Teflon lining makes things much less clog prone these days. many of you guys missed out on the old v3a and v3b days. you get about 5-10 plastic changes before that brass barrel was so tight you couldn't get filament through it anymore.

I got really good at declogging those ... heat them up over a half-hour, twist a 1/16 drill bit by hand into the plastic goop, let cool to room temperature. Then command it to heat again while pulling the drill-bit out with pliers. At some point the barrel got just warm enough to let loose and a giant clump of plastic would come out on the drill bit.

Yeah. Monday roll. I tried a third time....

One roll has caused:
2 extruder clogs and today the filament broke off (or was broken in the roll) while I was aeay.

Into the bin!