Atomic method, what do I do wrong?

[Erik-RS 0]

I've got extrusion problems (and even full stops of extrusion during printing) with my almost new UM2+.

So I first want to make sure all is clean.

I've tried the atomic method for cleaning several times, but when I do the "cold"pull I always break the filament and the end stays in the hot end. I've tried the standard temps according to UM and several others (higher and lower) and tried different materials (PLA, ABS and nGen). Since I read a lot of people use the method to satisfaction I'm wondering what I'm doing wrong.

Anyone?

[IRobertI 520]

Do you pull slowly or quickly? A quick yank usually works better.

[Erik-RS 0]

Pulling slowly doesn't work, because then I lift the printer

[DidierKlein 729]

Then it means that your cold temperature is too low

I usually pull at 90°c for PLA but it may vary... try a bit hotter. And apply a firm pull, it should pop out nicely, you can first try slowly to see how it reacts (you don't want to throw your printer to the ceiling )

[Erik-RS 0]

I sort of figured that out, I'll try cleaning with pla instead of abs. Though it didn't work with pla at 90 degrees neither when I just had the printer 2 weeks back and changed the nozzle.

[DidierKlein 729]

Well the temperature depends on your printer, but it should be around 90°c maybe 95°c if it's too soft when you pull try 2°c less. It's all about finding the perfect temp.

For ABS it's around 130°c

[Erik-RS 0]

I give up. As far as I understand this method is THE way to clean your nozzle. What material or temp I use, the filament breaks off at the entrance of the nozzle. I have the idea that some abs is baked to the side of the nozzle's interior and is narrowing the channel. That's maybe where my underextrusion and blockage comes from. I'll think about some sort of internal nozzle cleaner for the future (or just see what they would cost in larger quantities from a cnc machine and make them throwaway parts/disposables). For the moment I swap the 0,6 for the 0,4 nozzle, so the printer can at least go back to work. I'll try to get some proper aceton and soak the nozzle in that. See if that works. Amazing how hard it is to get proper aceton these days. The stuff they sell in the diy shop doesn't smell like aceton and won't melt my abs neither :(

[Morandir 3]

Erik,

I too thought I'd make a more determined effort to have a successful cold pull Atomic Method cleaning of my nozzle, to no avail. My filament always breaks off at the inlet to the heater block. I took my teflon isolator out and it looks like it's probably time to be replaced, or there was ABS baked on it. I cleaned it out (rather than replaced) and it had quit a bit less friction.

I wasn't able to try the pull again, but because I noticed a significant necking in the filament that broke off, I thought you may have a similar issue. When I get my up and running again, I'll try once more.

In lieu of that, you can always remove the olsson heater block and clean it out by hand at least. A little tedious, but I've been successful with a Xacto knife and a moment of zen. Just have whatever is left in the nozzle then.

Hopefully I'll be able to have a successful Atomic Pull one day...

[yellowshark 153]

Erik I have had success in the past by removing the nozzle and indeed the extruder and placing it/them in a pan of boiling water for several minutes. I then use a BBQ thingly (grip) to extract the piece and hold  the bore up to a light and use an implement to scrape/push pieces away/out from/of the bore.

Edited January 31, 2016 by Guest

[Erik-RS 0]

I succeeded finally (one time) with some PLA.

Already decided that I will have some more nozzles made, so I can replace them if need be.

Same goes for the teflon couplers.

Next time if I find myself in trouble I'll try heating the (loose) nozzle with a little gaz torch and clean with some alloy wire or something like that.

My extrusion problem proved to be a non-working hot-end cooling fan in the end. Took me some time (days :() to find out, but problem solved.

Cheers for the input, guys;)

[zoev89 73]

I wrote a gcode for atomic pull on my ultimaker original. It heats to 190 degress then turns the fan on and cools to 90 degrees. When reaching 90 it will turn the fan of and wait until you press the button (once you have pulled the filament). Once the key is pressed it turns the heater off.

It is a very simple gcode and instead of doing the setting in the menus again and again just start this print:P

Here is the gcode save it to your sd card and enjoy it. When other temperatures are needed just modify the temperatures. You can create different files with different temperatures for different materials.

(Don't know why it indents the G21 just remove the indent)

 

G21        ;metric valuesG90        ;absolute positioningM109 S190  ; set extruder op 190 and waitM106 S255  ; set fan op maxM109 S90  ; set extruder op 90M106 S0  ; set fan uitM117 Even wachten en pullM0 ;PauseM104 S0   ; extuder op 0

 

[gr5 2,178]

Nylon is a fantastic material to use for cold pulls. The "low" temp is closer to 130C though.

It's great because even when it is cold it is a bit flexible and when you pull hard it shrinks in cross section (pulls away from internal walls). Also it sticks to everything (burnt abs, burnt pla, dust, etc) and cleans things up nicely.

I used to do cold pulls all the time but I found that they aren't all that necessary - I rarely do them now.

[SyntaxTerror 344]

The few times I've had something completely and utterly stuck in my nozzle, I've resorted to the option of unscrewing the nozzle, grabbing it with a pair of tweezers and heating it gently (yeah, I said that!) with a small blowtorch. The filament runs out on its own in moments. Then you can cold pull out any leftovers afterwards, if need be. It's certainly a quick unclog.

[drayson 75]

I always change material (PLA, colors) this way to make sure to start with the new color without any mixing. I even don´t dismount the bowden, just pull.

It works nice when doing at the right temperature (~90-100°C) and with the right amount of "pull" :-)

[KevinWood 0]

I have a UMO with heated bed and hot end upgrades (does that make it a UMO+?). It has printed well for years but is now jamming and stopping extruding. I have replaced everything past the bowden tube, including a PTFE coupler and still having the same problem. The first layer is usually perfect, but at some point after that it stops extruding. I never get a finished print. I'm printing ABS at 242 and bed temp of 111. I've tried Atomic pulls but the filament always breaks in the coupler. I've even tried putting a cooling fan on the PTFE coupler. Every time it jams I have to take the whole hot end apart, soak in acetone and gradually remove all the ABS, which takes days. Any suggestions? I've getting desperate!