Dim3nsioneer 558
When you already have the camera in hands, please perform a cold pull and take a picture of the filament end.
When you already have the camera in hands, please perform a cold pull and take a picture of the filament end.
I'm with neotko on this one. I suspect that there's a small gap between the PTFE and the hotend causing plastic to leak out into the gap and locking things in place when it cools down.
Another option is that the third fan isn't running but I think that should be causing issues a bit later on in the print.
Just wild guessing. Make a photo of the head to see if you left the 1mm gap between the stainless part and the ptfe coupler. That if too loose or too tight can make a gap or make more preassure I think...
possible but i got an L2K insulator in between my coupler and the stainless part, so the gap is bigger than 1mm, it always worked before like this...
anyway, this is my printhead :
When you already have the camera in hands, please perform a cold pull and take a picture of the filament end.
I changed the PTFE and the nozzle today, so a cold pull would show a perfect clear filament I think?
The other area where filament residue can place it's on the barrel of the hotend... I think that's what @dim3nsioneer suspects
Edited by GuestI'm with neotko on this one. I suspect that there's a small gap between the PTFE and the hotend causing plastic to leak out into the gap and locking things in place when it cools down.
Another option is that the third fan isn't running but I think that should be causing issues a bit later on in the print.
I got an Olsson block with the other upgrades from 3Dsolex, I probably forgot to mention that. And my TF2K teflon is pushed correctly in the hot end coupler. (there is a L2K insulator in between though)
The 3rd fan is also running, I checked this
The other area where filament residue can place it's on the barrel of the hotend... I think that's what @dim3nsioneer suspects
I opened up my UM2 today to check the PTFE (it was still snow white on both sides and no deformation) and there was no filament in my hotend. (you mean this part right?)
All there parts on my printer are from 3Dsolex fyi.
No I mean on the barrel area of the block. Try to do the atomics
No I mean on the barrel area of the block. Try to do the atomics
Ok will do, I got the day off tomorrow (my UM2 is located in my office) so I will be able to do this thursday morning.
I wonder... I thought about this but never got the time to do it. @dim3nsioneer @IRobertI has anyone ever think about doing a gcode ending sequence that makes an auto atomic?
Something like
Gcode allow cold extrude
Wait for X temp
g1 e-X F fast initial speed
G1 e-X(10cm more) F slower speed
Gcode disable coldextrude
Ofc it would need tweaking to find the good speeds to make it right but sound doable?
Edited by GuestI have thought of it also.
You would also need to keep some pressure on the filament as it cools so it doesn't ooze and cause air pockets in the head.
I guess you would risk grinding but would be an interesting test.
Yeah, what Labern said. I've thought about it, but I feel like there's too much that can go wrong that would just end up costing you time regardless.
@neotko: My thoughts went the same way as @Labern's. I really would appreciate to have an automated cold pull as I always remove filament that way (the change filament routine of the UM2 is useless for me as it always produces a filament strain inside the Bowden tube which then blocks the filament flow.
@frederiekpascal: This might also be a source of your problems by the way... and @neotko was right with his assumption: the shape of the filament end is interesting - especially at the spots where there are transitions from one part of the hotend to the other. At the right temperature you might e.g. see a tiny gap which could result in a clog. The other advice I always give concerning clogs and chronic underextrusion is to use something to clean the filament before it enters the feeder.
An atomic pull device that is external of the printer for when you have just removed a nozzle could be doable.
would be nice to also have something clean up the outside of the tip 2.
@neotko: My thoughts went the same way as @Labern's. I really would appreciate to have an automated cold pull as I always remove filament that way (the change filament routine of the UM2 is useless for me as it always produces a filament strain inside the Bowden tube which then blocks the filament flow.
@frederiekpascal: This might also be a source of your problems by the way... and @neotko was right with his assumption: the shape of the filament end is interesting - especially at the spots where there are transitions from one part of the hotend to the other. At the right temperature you might e.g. see a tiny gap which could result in a clog. The other advice I always give concerning clogs and chronic underextrusion is to use something to clean the filament before it enters the feeder.
Thanks for your feedback. I forgot to mention, I also replaced the bowden tube and the problem continued...
As of today (after +750 printing hours in 4 months) I always use the "change material" on my UM2 when I change filament, I probably should start following this procedure? (found on 3dverkstan)
Doing it the lazy way
Now that you've read how to do the Atomic the traditional way here's an alternative method that you can do as well. We like to do this every time we change material. Instead of removing the bowden tube you can actually just push and pull filament at the feeder end. As long as the feeder motor is powered down (easily accomplished by power cycling the machine) it's not difficult to manually push filament into the hot end or pull it out.
So what we do when changing filament is to heat the print head up to printing temperature. Then push filament manually until it starts coming out of the nozzle. Then lower the temperature and finally pull the filament out with a quick tug once the temperature reaches ~85-90C. When you now insert the new material you wont have to flush the old colour out, you'll get the new colour immediately and you will have cleaned the nozzle at the same time.
You should snip off the cone shaped tip of the old filament as it will be slightly thicker and can be difficult to load properly.
Indeed. To manually pull the filament you might want to change to IRobertI feeder. Ofc users install it when they have problems, but the most instant improvement it's that you can 'release' the filament and push/pull manually.
Edit: So many typos omg...
Edited by GuestI don't think you might want to change to @IRobertI's feeder, it is a must. With the stock Ultimaker 2 I don't think you can push the filament in, and pulling it out can damage your electronics with the current it generates through the feeder-motor.. (I believe. No?)Indeed. To manually pull the filament you might want to change to IRobertI feeder. Ofc users install it when they have problems, but the most instant improvement it's that you can 'release' the filament and push/pull manually.
Edit: So many typos omg...
You pull it out when the feeder motor is not active.
I thought that when it is inactive it could also generate current that damages your electronics, but I stand corrected Better safe then sorry right
you could be right. i miss understood what you were saying.
I don't think you might want to change to @IRobertI's feeder, it is a must. With the stock Ultimaker 2 I don't think you can push the filament in, and pulling it out can damage your electronics with the current it generates through the feeder-motor.. (I believe. No?)
You can push it in. I've loaded that way since the UM2 first came out. It takes a bit of force to get it to "open up" though so for me it usually means I have to use two hands. But that's only when you load completely new filament in. Pushing and pulling the filament when it's already inserted is easy as long as the motor is powered off.
I've done the "lazy atomic" on all three of my machines here at home (many, many times), I've done it on all the demo machines at work and on every single machine I've tested before being shipped to a customer. Either I've been extremely lucky or it's not an issue.
And the same could be said for moving the head around manually. That also creates current that gets fed "backwards" to the board (it's enough power to light up a 3W LED I've put on one of my machines).
True that led light, my PWM external control connected to the 19-24v when the machine it's off and even unplugged, if I push down the bed the led goes on. Been wondering for months if that was good or bad or neither XD
If i recall correctly the UM2 should have protections in place for moving the motors by hand. The UMO not so much.
I havent read all replies, but you might want to try and loosen the feeder screw a bit. Having it too tight can cause grinding.
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Just wild guessing. Make a photo of the head to see if you left the 1mm gap between the stainless part and the ptfe coupler. That if too loose or too tight can make a gap or make more preassure I think...
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