Flashforge Finder not extruding during print, fine during Load Filament

Hi All, I've been using my Flashforge Finder for about 5 weeks now without any problems, however recently i changed the filament in the usual way and now it wont extrude PLA when printing. When I use the Load filament option, the filament is grabbed by the motor and drawn down, I can leave this a minute or so and see that the filament is moving freely through the extruder.

However when I print, nothing wants to come out. I first thought the bed was too close to the nozzle, so moving this away, even creating a large gap that should make the filament just extrude everywhere doesn't work. I don't hear any noises coming from the motors like the filament is blocked. I'm printing at 215c, although this is using the same .gx files as prior to the issue. I'm stumped as to what I should try to resolve this

So I followed Flashforge's video on cleaning the nozzle: https://www.youtube.com/watch?v=2Sm5hXN3mMg

It's printing at the moment, which is great news, but I don't think this is the fix to the underlying problem. I managed to get a print out last night after loading and unloading filament about 5 times. Could the root cause be something as simple as the nozzle needing to sit pre-heated for a few minutes prior to a print if the printer has had chance to completely cool?

Following the clean, it printed a model nicely, then when I started another, it laid down the first layer and stopped! I have no idea how to resolve this now

Does anyone have any advice please? I have attached an image below of what I am getting printed sometimes, this is when I actually manage to get filament out of the extruder.

So far I have;
- Calibrated the extruder head, followed by a bed level (this calibration sorts the auto leveller). Tested the print level height with a piece of paper between the nozzle and print bed
- Run the "Load Filament" option which feeds filament through the extruder smoothly, there doesnt appear to be any issue here
- Removed the extruder cover, taken off the stepper motor, then checked that the print nozzle is clear
- Looked at the stepper gear, this is clean. The pinch wheel or whatever it's called has a good grip on the filament, it actually leaves marks on the filament when it has passed through

Sometimes when printing a raft this comes out ok, my settings are 20mm/s to print this off. However the infill then either does not stick to the bed, or when it does it comes out very inconsistent. I can hear the extruder motor making a click noise and the filament is being fed about 1mm every half second or so. Should this be a smooth continuous push?

The printer has 552 hours on it, although I think thats powered on time, not pure print time. I have another Flashforge Finder that is a month older than this one and it is going strong, I have no issues with that. Although the printer is in a different location so it will be hard to chop and change parts for testing.



Attachment 11367
Attachment 11368

I've got a similiar problem on my creator. Loads filament fine, just doesn't print.
Thinking about changing the stepper motor controllers on the motherboard.

be easier for you as you can just try the ones from the working machine.

I’ve just swapped the stepper motor and attached cog with the working printer.

My “dodgy” motor in the working printer prints perfect.
My “dodgy” printer with other motor behaves the same.

This puts me back to either the nozzle or PTFE tube, heating not working correctly, or a software issue where it doesn’t want to extrude whilst printing.

One thing I did notice tho is that when I ran the heater to clear the nozzle on the working printer, it allowed me to push out the filament at around 190c, whereas on my dodgy printer I have to leave it a minute at 220c before I can push the filament through. When I get home I’ll take off the nozzle and inspect the tube and look for anything blocking it. Strange how the “load filament” facility works though.

ok, so after a few glasses of gin and some more checks on the printer, I took the heater assembly apart and it turns out that my PTFE tube is melted at the tip where the extruder is, and there is a hole half way down.

Firstly, I'm a complete n00b to printing, my printer has 550 hrs logged on it and its been running pretty much 24/7 since I bought it. For those who dont know, filament isn't the only consumable on a Flashforge printer! To protect the cooling tube and/or the extruder parts, there is a non-stick PTFE plastic liner that runs up from the nozzle to the stepper motor gear. This needs replacing every so often apparently!

I don't know if this tube exists on other models of printer, but it seems like a common replacement or upgrade for people is to replace this with a completely metal one, Micro Swiss seems to be a popular supplier when I stumbled across some YouTube videos for taking apart the hot end.

So my tube looked like this;
Attachment 11369

I'd appreciate it if anyone could tell me what could have caused this hole in the middle, as that is likely the root cause. Knowing the fix is good, but knowing how to stop it being a problem is better!

Also, if anyone has any other tips, or something that may seem completely simple, I'd love to hear it as I am learning as I go along. Spending a week on this issue has actually taught me a lot about 3D printers and in a broad sense how they work. Maybe starting off with a kit would have been better than a completely assembled printer so that I could get familiar with these things up front.

Same problem, please you know Diameters (ID, OD) of this tube?

Can you put in a link of the replacement part? I got the same problem.
Do you know wy the printer works fine while loading and not while printing? what does that hole got to do with that ?

I think sometimes the tubes just wear out.
Had the same issue recently on my delta. The tube actually managed to snap in half !
Look on amazon for 3mm ptfe tubing with 2mm internal diameter.
It's cheap and easily cut to size.

Quote:

---

Originally Posted by curious aardvark

I think sometimes the tubes just wear out.
Had the same issue recently on my delta. The tube actually managed to snap in half !
Look on amazon for 3mm ptfe tubing with 2mm internal diameter.
It's cheap and easily cut to size.

---

I found a plastic one. Did anyone manage to find a metal one?

You can buy a micro swiss all metal throat tube, although to be honest i had less luck with that than with the PTFE tube. I found that the temps needed to be higher, but the whole thing was more susceptible to jamming.

The best solution is to get any PTFE tube from Amazon (4mm outer, 2mm inner), and cut it to the right length.

I found that the hole being created in the tube was due to the loading procedure. First you heat the hotend to required temp, the pull out the old filament, this temp must be enough to soften the PTFE ready for the actual cause, which is when you then put the new filament in it grabs the side and pokes a hole in it. I found the best way to swap filament in this printer is to make sure the hot end is cool before inserting new filament, press it all the way until it stops in the nozzle, then heat it to loading temp and then start pushing it through the nozzle. Haven't lost a tube by doing this so far! Although I do also replace the PTFE on a semi regular basis.